Articoli di riviste: "LITHIUM /PVDF"

1

Hu, Yinglu, Li Liu, Jingwei Zhao, Dechao Zhang, Jiadong Shen, Fangkun Li, Yan Yang et al. "Lithiophilic Quinone Lithium Salt Formed by Tetrafluoro-1,4-Benzoquinone Guides Uniform Lithium Deposition to Stabilize the Interface of Anode and PVDF-Based Solid Electrolytes". Batteries 9, n. 6 (12 giugno 2023): 322. http://dx.doi.org/10.3390/batteries9060322.

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Poly(vinylidene fluoride) (PVDF)-based composite solid electrolytes (CSEs) are attracting widespread attention due to their superior electrochemical and mechanical properties. However, the PVDF has a strong polar group -CF2-, which easily continuously reacts with lithium metal, resulting in the instability of the solid electrolyte interface (SEI), which intensifies the formation of lithium dendrites. Herein, Tetrafluoro-1,4-benzoquinone (TFBQ) was selected as an additive in trace amounts to the PVDF/Li-based electrolytes. TFBQ uniformly formed lithophilic quinone lithium salt (Li2TFBQ) in the SEI. Li2TFBQ has high lithium-ion affinity and low potential barrier and can be used as the dominant agent to guide uniform lithium deposition. The results showed that PVDF/Li-TFBQ 0.05 with a mass ratio of PVDF to TFBQ of 1:0.05 had the highest ionic conductivity of 2.39 × 10−4 S cm−1, and the electrochemical stability window reached 5.0 V. Moreover, PVDF/Li-TFBQ CSE demonstrated superior lithium dendrite suppression, which was confirmed by long-term lithium stripping/sedimentation tests over 2000 and 650 h at a current of 0.1 and 0.2 mA cm−2, respectively. The assembled solid-state LiNi0.6Co0.2Mn0.2O2||Li cell showed an excellent performance rate and cycle stability at 30 °C. This study greatly promotes the practical research of solid-state electrolytes.

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Barbosa, João, José Dias, Senentxu Lanceros-Méndez e Carlos Costa. "Recent Advances in Poly(vinylidene fluoride) and Its Copolymers for Lithium-Ion Battery Separators". Membranes 8, n. 3 (19 luglio 2018): 45. http://dx.doi.org/10.3390/membranes8030045.

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The separator membrane is an essential component of lithium-ion batteries, separating the anode and cathode, and controlling the number and mobility of the lithium ions. Among the polymer matrices most commonly investigated for battery separators are poly(vinylidene fluoride) (PVDF) and its copolymers poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and poly(vinylidene fluoride-cochlorotrifluoroethylene) (PVDF-CTFE), due to their excellent properties such as high polarity and the possibility of controlling the porosity of the materials through binary and ternary polymer/solvent systems, among others. This review presents the recent advances on battery separators based on PVDF and its copolymers for lithium-ion batteries. It is divided into the following sections: single polymer and co-polymers, surface modification, composites, and polymer blends. Further, a critical comparison between those membranes and other separator membranes is presented, as well as the future trends on this area.

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Kim, Min Ji, Chang Hee Lee, Mun Hui Jo e Soon Ki Jeong. "Electrochemical Decomposition of Poly(Vinylidene Fluoride) Binder for a Graphite Negative Electrode in Lithium-Ion Batteries". Materials Science Forum 893 (marzo 2017): 127–31. http://dx.doi.org/10.4028/www.scientific.net/msf.893.127.

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To clarify the electrochemical decomposition of poly (vinylidene fluoride) (PVdF) used as a binder for lithium-ion batteries while simultaneously verifying the correlation between electrode resistance and the PVdF content in graphite negative electrodes, in this study, we applied lithium bis (trifluoromethanesulfonyl) imide, which suppresses graphite exfoliation, as a salt. As a result, the electrochemical decomposition of PVdF was observed at a higher potential than that at which the electrolyte was decomposed during the reduction process. Additionally, this study demonstrated (through electrochemical impedance spectroscopy analysis) that electrode resistances such as solid electrolyte interface and charge transfer resistance proportionally increased with the PVdF content.

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4

Nikodimos, Yosef, Wei-Nien Su e Bing-Joe Hwang. "Lithium Dendrite Growth Suppression in Anode-Free Lithium Battery Using Bifunctional Electrospun Gel Polymer Electrolyte Membrane". ECS Meeting Abstracts MA2023-01, n. 6 (28 agosto 2023): 998. http://dx.doi.org/10.1149/ma2023-016998mtgabs.

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Anode free Li metal battery (AFLMB) are being intensively investigating in recent years as a means to achieve higher capacity when compared with standard Li metal batteries. However, the severe electrolyte decomposition during plating/stripping cycles, that causes fast Li dendrite growth and quick capacity fading, is challenging for its commercialization. Herein, poly (vinylidene fluoride-hexafluoropropylene) polymer containing Li1.6Al0.4Mg0.1Ge1.5(PO4)3 ceramic filler (90:10 w% ratio, PVDF-HFP-10) gel polymer electrolyte (GPE) is employed for the first time in AFLMB to suppress the Li dendrite growth and homogeneous Li deposition is achieved during Li metal plating/stripping. The PVDF-HFP-10 based membrane is manufactured using electrospinning technique, which is well known and effective technique to increase the amount of crystalline β-phase of PVDF-HFP, on Cu collector foil. Particularly, a pure crystalline β-phase of PVDF-HFP has been observed in the adhesion layer sticked with Cu collector as confirmed from the analysis of Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy measurements. The adhesion layer is further investigated using X-ray absorption spectroscopy (XAS), grazing angle X-ray diffraction (GAXRD) and X-ray photoelectron spectroscopy (XPS) techniques. The GAXRD analysis reveals Cu collector undergoes slight reconstruction of its (100) facets surface to (200) facets in the presence of the adhesion layer. Moreover, depth XPS analysis confirmed that the alignment of F atoms in the adhesion layer is toward the Cu collector which can play an important role for homogeneous Li deposition. Based on these findings, a novel approach is developed to prepare GPE, without peeling off the electrospun PVDF-HFP membrane from Cu collector to take advantage of the adhesion layer. The electrospun PVDF-HFP membrane GPE unpeeled off from its Cu collector (Cu@PVDF-HFP-10) prepared using novel method provides bifunctional applications, as electrolyte and as an artificial solid-electrolyte interphase (ASEI). The strong electrostatic interaction between the fiber sheet and its collector foil forms an adhesion layer (⁓0.5μm) which acts as ASEI prevents electrolyte decomposition. The Cu@PVDF-HFP-10|Li anode free cell enables uniform and highly compacted Li platting, excellent electrochemical performance, and high coulombic efficiency (CE) even at a high current density up to 5 mA cm− 2 (CE, 97.14%) after 200 cycles using 2 mAh cm− 2 capacity loading. Conversely, nonuniform and thick Li deposition is observed in the GPE prepared by conventional method (PVDF-HFP-10), due to poor contact between the membrane and the electrode, achieved only 90.08% CE after 100 cycles at 5 mA cm− 2. Post-cycling analyses using titration-gas chromatography (TGC) and XPS techniques indicated that the new strategy is conducive to prevent dead Li metal formation as well as to create a carbonate-free, robust, and stable SEI convenient to develop sustainable AFLMB system. Cycling performance of the Cu@PVDF-HFP-10 GPE utilized in the Cu|NMC AFLMB configuration delivered much better electrochemical performance than the PVDF-HFP-10 GPE (prepared by traditional method) and organic liquid electrolytes.

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5

Wang, Zhiqun, Shaokang Tian, Shangda Li, Lei Li, Yimei Yin e Zifeng Ma. "Lithium sulfonate-grafted poly(vinylidenefluoride-hexafluoro propylene) ionomer as binder for lithium-ion batteries". RSC Advances 8, n. 36 (2018): 20025–31. http://dx.doi.org/10.1039/c8ra02122h.

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6

Castillo, Julen, Adrián Robles-Fernandez, Rosalía Cid, José Antonio González-Marcos, Michel Armand, Daniel Carriazo, Heng Zhang e Alexander Santiago. "Dehydrofluorination Process of Poly(vinylidene difluoride) PVdF-Based Gel Polymer Electrolytes and Its Effect on Lithium-Sulfur Batteries". Gels 9, n. 4 (14 aprile 2023): 336. http://dx.doi.org/10.3390/gels9040336.

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Gel polymer electrolytes (GPEs) are emerging as suitable candidates for high-performing lithium-sulfur batteries (LSBs) due to their excellent performance and improved safety. Within them, poly(vinylidene difluoride) (PVdF) and its derivatives have been widely used as polymer hosts due to their ideal mechanical and electrochemical properties. However, their poor stability with lithium metal (Li0) anode has been identified as their main drawback. Here, the stability of two PVdF-based GPEs with Li0 and their application in LSBs is studied. PVdF-based GPEs undergo a dehydrofluorination process upon contact with the Li0. This process results in the formation of a LiF-rich solid electrolyte interphase that provides high stability during galvanostatic cycling. Nevertheless, despite their outstanding initial discharge, both GPEs show an unsuitable battery performance characterized by a capacity drop, ascribed to the loss of the lithium polysulfides and their interaction with the dehydrofluorinated polymer host. Through the introduction of an intriguing lithium salt (lithium nitrate) in the electrolyte, a significant improvement is achieved delivering higher capacity retention. Apart from providing a detailed study of the hitherto poorly characterized interaction process between PVdF-based GPEs and the Li0, this study demonstrates the need for an anode protection process to use this type of electrolytes in LSBs.

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7

Yang, Shan Shan, Xiong Liu, Jiang Nan Shen e Cong Jie Gao. "Comparison Study of PVDF-HMn₂O₄ and PES-HMn₂O₄ Membrane-Type Adsorbents for Lithium Adsorption/Desorption". Applied Mechanics and Materials 633-634 (settembre 2014): 517–20. http://dx.doi.org/10.4028/www.scientific.net/amm.633-634.517.

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Much attention has been paid to membrane-type lithium adsorbents to overcome the shortages of the leakage of powder, poor permeability and difficult recycle for powder lithium adsorbents. In this work, a series of membrane-type adsorbents of spinel-type manganese oxides were converted from lithium manganese oxide precursor membranes by acid treatment. Precursor membranes were prepared by solvent exchange method using polyvinylidene fluoride (PVDF) and Polyether sulphone (PES) respectively as binders, powder LiMn2O4 as the precursor and N,N-dimethyl acetamide (DMAc) as the solvent. The preparation conditions were investigated by changing the binder and the concentration of powder LiMn2O4. The surfaces and morphology of membrane-type adsorbents were observated by scanning electron microscope. The comparation of the capacities of lithium desorption from precursor and adsorption for membrane-type adsorbents based on different binders shows that PVDF is more suitable to be the binder than PES with liquid film thickness of 0.25mm, and the proper concentration of PVDF and powered LiMn2O4 are respectively 12% and 60%.

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8

Zhu, Shu Guang, e Wen Zhi He. "Removal of Organic Impurities in Lithium Cobalt Oxide from Spent Lithium Ion Batteries by Ultrasonic Irradiation". Advanced Materials Research 864-867 (dicembre 2013): 1937–40. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.1937.

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In the present work, spent LiCoO2 was processed to remove impurities by ultrasound with the aim to renovate its electrochemical characteristics. The composition and amount of organic materials remained in the LiCoO2 particle surface were characterized by GC-MS, FT-IR and TGA, respectively. The morphology and particle sizes of PVDF (Polyvinylidene fluoride) was analyzed by SEM. Experimental results show that ultrasonic cavitation could be effectively used to remove organic substance stuck on LiCoO2 surface. At room temperature, the spent LiCoO2 was successfully remove impurities, including EC (Ethylene carbonate) and PVDF, with ultrasound applied for 12 h. It can be considered that most of the PVDF (82.0 wt.%) has decomposed under ultrasonic irradiation. Furthermore, the EC has completely decomposed under such ultrasonic irradiation.

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9

Zhu, Pei, Jiadeng Zhu, Jun Zang, Chen Chen, Yao Lu, Mengjin Jiang, Chaoyi Yan, Mahmut Dirican, Ramakrishnan Kalai Selvan e Xiangwu Zhang. "A novel bi-functional double-layer rGO–PVDF/PVDF composite nanofiber membrane separator with enhanced thermal stability and effective polysulfide inhibition for high-performance lithium–sulfur batteries". Journal of Materials Chemistry A 5, n. 29 (2017): 15096–104. http://dx.doi.org/10.1039/c7ta03301j.

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A novel, bi-functional double-layer reduced graphene oxide (rGO)–polyvinylidene fluoride (PVDF)/PVDF membrane was fabricated by a simple electrospinning technique and was used as a promising separator for lithium–sulfur batteries.

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10

Kim, Gyuyoung, Jin-Hee Noh, Horim Lee, Jaehak Shin e Dongjin Lee. "Roll-to-Roll Gravure Coating of PVDF on a Battery Separator for the Enhancement of Thermal Stability". Polymers 15, n. 20 (16 ottobre 2023): 4108. http://dx.doi.org/10.3390/polym15204108.

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The polyethylene lithium-ion battery separator is coated with a polymer by means of a roll-to-roll (R2R) gravure coating scheme to enhance the thermal stability. The polyvinylidene fluoride (PVDF) or polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) is gravure-coated, and the pores are fabricated based on online nonsolvent-induced phase separation (NIPS). N-methylpyrrolidone is used as a solvent, and deionized water or a methanol mixture thereof is exploited as a nonsolvent in NIPS. Scanning electron microscopy confirms that the polymer film is formed and that the pores are well developed. The thermal shrinkage decreased by 20.0% and 23.2% compared to that of the bare separator due to the coating of PVDF and PVDF-HFP, respectively. The R2R gravure coating scheme is proven to be fully functional to tailor the properties of lithium-ion battery separators.

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11

Tizzani, Cosimo, Giovanni B. Appetecchi, Maria Carewska, Guk-Tae Kim e Stefano Passerini. "Investigation of the Electrochemical Properties of Polymer–LiX–Ionic Liquid Ternary Systems". Australian Journal of Chemistry 60, n. 1 (2007): 47. http://dx.doi.org/10.1071/ch06293.

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The electrochemical properties of ternary systems that consist of a polymer, a lithium salt, and an ionic liquid that shares the same anion (TFSI, bis(trifluoromethansulfonyl)imide) are reported and compared. The investigation involved two different polymers (PVdF-HFP and PTFE) that were selected because of their common use in lithium-based electrochemical devices. It was found that PVdF-HFP swelled by the ionic liquid used in the work while porous PTFE remained inert. The ternary electrolytes showed interesting ionic conductivities. However, the presence of fluorinated polymers resulted in poor interfacial properties with lithium metal electrodes.

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12

Li, Wenjun, Zhaohui Li, Chenlu Yang, Qizhen Xiao, Gangtie Lei e Yanhuai Ding. "A capsule-type gelled polymer electrolyte for rechargeable lithium batteries". RSC Advances 6, n. 53 (2016): 47833–39. http://dx.doi.org/10.1039/c6ra07341g.

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13

Sung, Sang Hoon, Sunhyung Kim, Jeong Hoon Park, Jun Dong Park e Kyung Hyun Ahn. "Role of PVDF in Rheology and Microstructure of NCM Cathode Slurries for Lithium-Ion Battery". Materials 13, n. 20 (13 ottobre 2020): 4544. http://dx.doi.org/10.3390/ma13204544.

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A binder plays a critical role in dispersion of coating liquids and the quality of coating. Poly(vinylidene fluoride) (PVDF) is widely used as a binder in cathode slurries; however, its role as a binder is still under debate. In this paper, we study the role of PVDF on the rheology of cathode battery slurries consisting of Li(Ni1/3Mn1/3Co1/3)O2 (NCM), carbon black (CB) and N-methyl-2-pyrrolidone (NMP). Rheology and microstructure of cathode slurries are systemically investigated with three model suspensions: CB/PVDF/NMP, NCM/PVDF/NMP and NCM/CB/PVDF/NMP. To highlight the role of PVDF in cathode slurries, we prepare the same model suspensions by replacing PVDF with PVP, and we compare the role of PVDF to PVP in the suspension rheology. We find that PVDF adsorbs neither onto NCM nor CB surface, which can be attributed to its poor affinity to NCM and CB. Rheological measurements suggest that PVDF mainly increases matrix viscosity in the suspension without affecting the microstructure formed by CB and NCM particles. In contrast to PVDF, PVP stabilizes the structure of CB and NCM in the model suspensions, as it is adsorbed on the CB surface. This study will provide a useful insight to fundamentally understand the rheology of cathode slurries.

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Muzadi, Hasim, Nayla Zahra Kamalia, Titik Lestariningsih e Yayuk Astuti. "Effect of LiTFSI Electrolyte Salt Composition on Characteristics of PVDF-PEO-LiTFSI-Based Solid Polymer Electrolyte (SPE) for Lithium-Ion Battery". Molekul 18, n. 1 (20 marzo 2023): 98. http://dx.doi.org/10.20884/1.jm.2023.18.1.6446.

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A lithium-ion battery with PVDF-PEO synthetic polymer sheet added by LiTFSI electrolyte salt has been made by assembling method. This study aims to determine the effect of LiTFSI salt concentration on the performance of lithium-ion batteries. The composition of LiTFSI electrolyte salts was varied into 5%; 10%; 15%; and 20%. Several characterizations were carried out to determine battery performance, including Electrochemical Impedance Spectrometry (ElS), Cyclic Voltammetry (CV), Charge/Discharge (CD), and Lithium Transference Number (LTN). The results showed that the synthesized separator sheet with a LiTFSI salt composition of 20% producing voltage, ionic conductivity, and lithium-ion transfer number of 0.72 V; 3.94 x 10-8 SCm-1; and 0.895, respectively is potential for lithium-ion batteries application. These results indicate the use of LiTFSI electrolyte salts with a concentration of 20% shows the best performance for PVDF-PEO-LiTFSI-based lithium-ion batteries.

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Gong, Wenzheng, Xinyu Wang, Zheng Li, Junfeng Gu, Shilun Ruan e Changyu Shen. "A high-strength PPESK/PVDF fibrous membrane prepared by coaxial electrospinning for lithium-ion battery separator". High Performance Polymers 31, n. 8 (28 novembre 2018): 948–58. http://dx.doi.org/10.1177/0954008318814154.

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Electrospinning fibrous membranes have attracted a great deal of attention because of their advantages, including uniform pore size, large ratio surface area, and high porosity. For extended application in lithium-ion battery, it is essential to further improve their electrochemical, mechanical, and thermal properties. In this work, a new poly (phthalazine ether sulfone ketone) (PPESK)/polyvinyli-denefluoride (PVDF) core/shell fibrous membrane was fabricated via the coaxial electrospinning technique, followed by hot press. The PPESK/PVDF membrane hot pressed at 160°C exhibits excellent comprehensive performance, including large porosity (80%), high electrolyte uptake (805%), and excellent thermal stability (at 200°C). Moreover, due to the improved bonding effect derived from the solidification of the PVDF shell layer after the hot press, the mechanical property of the membrane is effectively enhanced. The electrochemical tests also indicate that the PPESK/PVDF membrane shows larger ionic conductivity and lower interfacial resistance when compared with commercial microporous polypropylene separator. In addition, simulated cells assembled with the PPESK/PVDF membrane present superior discharge capacity, stable cycle performance, and excellent rate capability. Therefore, the hot-pressed coaxial PPESK/PVDF fibrous membrane has the potential to be a promising candidate as the separator for high-performance lithium-ion battery.

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Zhang, Congli, Zeyu Geng, Ting Meng, Fei Ma, Xueya Xu, Yang Liu e Haifeng Zhang. "Multi−Functional Gradient Fibrous Membranes Aiming at High Performance for Both Lithium–Sulfur and Zinc–Air Batteries". Electronics 12, n. 4 (9 febbraio 2023): 885. http://dx.doi.org/10.3390/electronics12040885.

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Lithium–sulfur batteries have been considered one of the most promising energy storage batteries in the future of flexible and wearable electronics. However, the shuttling of polysulfides, low sulfur utilization, and bad cycle stability restricted the widespread application of lithium–sulfur batteries. Currently, gradient materials with multiple functions can solve those defects simultaneously and can be applied to various parts of batteries. Herein, an electrospinningtriple−gradient Co−N−C/PVDF/PAN fibrous membrane was prepared and applied to lithium–sulfur batteries. The Co−N−C fibrous membrane provided efficient active sites, excellent electrode conductivity, and boosted polysulfide confinement. At the same time, the PVDF/PAN membrane enhances electron transfer and lithium−ion diffusion. As a result, the integrated S@Co−N−C/PVDF/PAN/Li battery delivered a high initial capacity of 1124.1 mA h g−1. Even under high sulfur loading (6 mg cm−2), this flexible Li–S battery still exhibits high areal capacity (846.9 mA h cm−2) without apparent capacity attenuation and security issues. Meanwhile, the gradient fibrous membranes can be used in zinc–air batteries, and the same double−gradient Co−N−C/PVDF membranes were also used as a binder−free air cathode with bifunctional catalytic activity and a facile hydrophobic and aerophile membrane, delivering remarkable cycling stability and small voltage gap in aqueous ZABs. The well−tunable structures and materials of the gradient strategy would bring inspiration for excellent performance in flexible and wearable energy storage devices.

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Wang, Yuan, Chuanqiang Yin, Zhenglin Song, Qiulin Wang, Yu Lan, Jinpeng Luo, Liwen Bo, Zhihao Yue, Fugen Sun e Xiaomin Li. "Application of PVDF Organic Particles Coating on Polyethylene Separator for Lithium Ion Batteries". Materials 12, n. 19 (25 settembre 2019): 3125. http://dx.doi.org/10.3390/ma12193125.

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Surface coating modification on a polyethylene separator serves as a promising way to meet the high requirements of thermal dimensional stability and excellent electrolyte wettability for lithium ion batteries (LIBs). In this paper, we report a new type of surface modified separator by coating polyvinylidene fluoride (PVDF) organic particles on traditional microporous polyethylene (PE) separators. The PE separator coated by PVDF particles (PE-PVDF separator) has higher porosity (61.4%), better electrolyte wettability (the contact angle to water was 3.28° ± 0.21°) and superior ionic conductivity (1.53 mS/cm) compared with the bare PE separator (51.2%, 111.3° ± 0.12°, 0.55 mS/cm). On one hand, the PVDF organic polymer has excellent organic electrolyte compatibility. On the other hand, the PVDF particles contain sub-micro spheres, of which the separator can possess a large specific surface area to absorb additional electrolyte. As a result, LIBs assembled using the PE-PVDF separator showed better electrochemical performances. For example, the button cell using a PE-PVDF as the separator had a higher capacity retention rate (70.01% capacity retention after 200 cycles at 0.5 C) than the bare PE separator (62.5% capacity retention after 200 cycles at 0.5 C). Moreover, the rate capability of LIBs was greatly improved as well—especially at larger current densities such as 2 C and 5 C.

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Xiong, Xiaosong, Ruoyu Zhi, Qi Zhou, Wenqi Yan, Yusong Zhu, Yuhui Chen, Lijun Fu, Nengfei Yu e Yuping Wu. "A binary PMMA/PVDF blend film modified substrate enables a superior lithium metal anode for lithium batteries". Materials Advances 2, n. 13 (2021): 4240–45. http://dx.doi.org/10.1039/d1ma00121c.

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Lee, Kibae, Yoonsang Jeong, Chong Hyun Lee, Jongkil Lee, Hee-Seon Seo e Yohan Cho. "Impedance Coupled Voltage Boosting Circuit for Polyvinylidene Fluoride Based Energy Harvester". Sensors 23, n. 1 (23 dicembre 2022): 137. http://dx.doi.org/10.3390/s23010137.

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Polyvinylidene fluoride (PVDF) is an emerging method for energy harvesting by fluid motion with superior flexibility. However, the PVDF energy harvester, which has a high internal impedance and generates a low voltage, has a large power transmission loss. To overcome this problem, we propose an impedance-coupled voltage-boosting circuit (IC-VBC) that reduces the impedance of the PVDF energy harvester and boosts the voltage. SPICE simulation results show that IC-VBC reduces the impedance of the PVDF energy harvester from 4.3 MΩ to 320 kΩ and increases the output voltage by 2.52 times. We successfully charged lithium-ion batteries using the PVDF energy harvester and IC-VBC with low-speed wind power generation.

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Widiyandari, Hendri, Nur Ahmad Fauzan, Risa Suryana e Oki Ade Putra. "Synthesis of PVDF-SiO₂ nanofiber membrane using electrospinning multi-jet vertical on conveyor collector as a lithium-ion battery separator". Journal of Physics: Conference Series 2498, n. 1 (1 maggio 2023): 012002. http://dx.doi.org/10.1088/1742-6596/2498/1/012002.

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Abstract Research on synthesis of PVDF-SiO2 nanofiber membrane by electrospinning multi-jet vertical method on conveyor collector as a lithium-ion battery separator was systematically investigated. Various voltages of 15 kV, 16 kV, and 17 kV and types of PVDF such as Aldrich, Solvay, and both mixtures were used for nanofiber membrane synthesis. The nanofiber membrane was synthesized for 4 hours with a distance between the tip of the needle, and the collector was 10 cm, with a flow rate of 2.6 mL/hour and a collector speed of 37 rpm. Furthermore, the results were tested for the physicochemical properties of the nanofiber. Solution B (PVDF Solvay) treated with 17kV has the largest porosity percentage value of membrane, which was 84.659%. The optimum shrinkage ratio test was from solution A (PVDF Aldrich) with 15 kV, 16 kV, and 17 kV voltages. The smallest average diameter nanofiber was obtained from solution B (PVDF Solvay) with a voltage of 15kV. The FTIR spectrum was not affected by voltages variations. In addition, the nanofiber membrane was assembled in the battery using Aldrich, Solvay, and mixed PVDF types. The battery was then tested for the electrochemical properties of the lithium-ion battery. Solution B (Solvay) has the optimum charge-discharge results showing a specific charge of 107.472 mAh/g and a specific discharge of 77.990 mAh/g.

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Mohanty, Debabrata, Shu-Yu Chen e I.-Ming Hung. "Effect of Lithium Salt Concentration on Materials Characteristics and Electrochemical Performance of Hybrid Inorganic/Polymer Solid Electrolyte for Solid-State Lithium-Ion Batteries". Batteries 8, n. 10 (9 ottobre 2022): 173. http://dx.doi.org/10.3390/batteries8100173.

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Lithium-ion batteries are popular energy storage devices due to their high energy density. Solid electrolytes appear to be a potential replacement for flammable liquid electrolytes in lithium batteries. This inorganic/hybrid solid electrolyte is a composite of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, (poly(vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) polymer and sodium superionic conductor (NASICON)-type Li1+xAlxTi2−x(PO4)3 (LATP) ceramic powder. The structure, morphology, mechanical behavior, and electrochemical performance of this composite solid electrolyte, based on various amounts of LiTFSI, were investigated. The lithium-ion transfer and conductivity increased as the LiTFSI lithium salt concentration increased. However, the mechanical strength apparently decreased once the percentage of LITFSI was over 60%. The hybrid electrolyte with 60% LiTFSI content showed high ionic conductivity of 2.14 × 10−4 S cm−1, a wide electrochemical stability window (3–6 V) and good electrochemical stability. The capacity of the Li|60% LiTFSI/PVDF-HFP/LATP| LiFePO4 solid-state lithium-metal battery was 103.8 mA h g−1 at 0.1 C, with a high-capacity retention of 98% after 50 cycles.

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Wu, Yi-Shiuan, Chun-Chen Yang, Sin-Ping Luo, Yi-Lin Chen, Chao-Nan Wei e Shingjiang Jessie Lue. "PVDF-HFP/PET/PVDF-HFP composite membrane for lithium-ion power batteries". International Journal of Hydrogen Energy 42, n. 10 (marzo 2017): 6862–75. http://dx.doi.org/10.1016/j.ijhydene.2016.11.201.

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23

Zhang, M. Y., M. X. Li, Z. Chang, Y. F. Wang, J. Gao, Y. S. Zhu, Y. P. Wu e W. Huang. "A Sandwich PVDF/HEC/PVDF Gel Polymer Electrolyte for Lithium Ion Battery". Electrochimica Acta 245 (agosto 2017): 752–59. http://dx.doi.org/10.1016/j.electacta.2017.05.154.

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Ahmad, A. L., U. R. Farooqui e N. A. Hamid. "Porous (PVDF-HFP/PANI/GO) ternary hybrid polymer electrolyte membranes for lithium-ion batteries". RSC Advances 8, n. 45 (2018): 25725–33. http://dx.doi.org/10.1039/c8ra03918f.

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25

Liang, Yin Zheng, Si Chen Cheng, Jian Meng Zhao, Chang Huan Zhang e Yi Ping Qiu. "Preparation and Characterization of Electrospun PVDF/PMMA Composite Fibrous Membranes-Based Separator for Lithium-Ion Batteries". Advanced Materials Research 750-752 (agosto 2013): 1914–18. http://dx.doi.org/10.4028/www.scientific.net/amr.750-752.1914.

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Abstract (sommario):

The poly (vinylidene fluoride)/poly (methyl methacrylate)(PVDF/PMMA) composite fibrous membranes with different blend ratio for use as separator of lithium-ion batteries have been developed by electrospinning technique. The surface morphology and crystal structure of electrospun PVDF/PMMA composite fibrous membranes are characterized using scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and differential scanning calorimetry (DSC).The results indicated that the addition of PMMA into PVDF increased the fiber diameter, decreased the crystalline of electrospun composite fibrous membranes and the good molecular level interaction between these two polymers were obtained. Meanwhile,electrospun PVDF/PMMA (90/10) composite fibrous membranes exhibited the highest ionic conductivity of 2.54×10-3S/cm at room temperature with electrochemical stability of up to 5.0V.

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26

Seidel, S. M., S. Jeschke, P. Vettikuzha e H. D. Wiemhöfer. "PVDF-HFP/ether-modified polysiloxane membranes obtained via airbrush spraying as active separators for application in lithium ion batteries". Chemical Communications 51, n. 60 (2015): 12048–51. http://dx.doi.org/10.1039/c5cc04424c.

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27

Basri, N. H., S. Ibrahim e N. S. Mohamed. "PVDF-HFP/PVC Blend Based Lithium Ion Conducting Polymer Electrolytes". Advanced Materials Research 287-290 (luglio 2011): 100–103. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.100.

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Abstract (sommario):

Flexible free standing polymer electrolyte films have been successfully prepared using a blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(vinyl chloride) (PVC) doped with lithium perchlorate (LiClO4). The conductivity of the film was influenced by salt concentration and the degree of crystallinity. An optimum room temperature conductivity obtained was 2.10 x 10-4S cm-1for PVDF-HFP/PVC containing 35 wt.% LiClO4. The temperature-dependent conductivity of the polymer films exhibited VTF-type behaviour.

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28

Luo, Jing, Rung-Chuan Lee, Jian-Ting Jin, Yu-Ting Weng, Chia-Chen Fang e Nae-Lih Wu. "A dual-functional polymer coating on a lithium anode for suppressing dendrite growth and polysulfide shuttling in Li–S batteries". Chemical Communications 53, n. 5 (2017): 963–66. http://dx.doi.org/10.1039/c6cc09248a.

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29

Ahmad, Azizah Hanom, Ri Hanum Yahaya Subban, R. Zakaria e A. M. M. Ali. "Comparative Studies on Li/LiI-Li₂WO₄-Li₃PO₄/Metal Oxide Electrochemical Cells". Materials Science Forum 517 (giugno 2006): 275–77. http://dx.doi.org/10.4028/www.scientific.net/msf.517.275.

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Abstract (sommario):

A series of experiment has been carried out to study the electrochemical performances of lithium primary cells using different cathode materials. The cathode material was made of metal oxide, electrolyte, activated carbon, and PVdF with a wt. ratio of 60: 20:10:10. PVdF was added as a binder. The metal oxides used are MnO2 and V2O5. The anode was made up of lithium metal and LiI-Li2WO4-Li3PO4 compound is used as an electrolyte. In this work the open circuit voltage (OCV) of Li/MnO2 and Li/V2O5 obtained is about 3.0 V and 3.2 V respectively. This shows that LiI-Li2WO4-Li3PO4 compound is lithium ion conductor. Lithium cell showed better performance at 100º C than at room temperature. Among these two types of cells investigated, cell Li/V2O5 worked better than the Li/MnO2 cell at room temperature and at 100°C as this cell exhibits the longest continuous discharge time and the highest OCV.

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Boudin, F., X. Andrieu, C. Jehoulet e I. I. Olsen. "Microporous PVdF gel for lithium-ion batteries". Journal of Power Sources 81-82 (settembre 1999): 804–7. http://dx.doi.org/10.1016/s0378-7753(99)00154-8.

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31

Yen, Dean, Sha Tan, Xiao-Qing Yang, Yu-chen Karen Chen-Wiegart e Enyuan Hu. "Electrochemical and Structural Study on PVDF-Based Polymer Electrolytes for Solid-State Batteries". ECS Meeting Abstracts MA2022-02, n. 4 (9 ottobre 2022): 425. http://dx.doi.org/10.1149/ma2022-024425mtgabs.

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Abstract (sommario):

Lithium-ion batteries are widely used today in powering devices from portable electronics to electric vehicles. Despite their great success, this battery chemistry relies on organic solvent-based liquid electrolytes which are highly flammable, leading to major safety concerns. In contrast, solid-state batteries, which are based on solid-state electrolytes, are regarded to have much better safety characteristics and potentially higher energy density than the conventional lithium-ion batteries. Solid-state electrolytes usually include ceramics, polymers, gels, and composites. Among them, polymer materials have attracted considerable attention due to their great interfacial contact, flexibility, and easy fabrication. In particular, polyvinylidene fluoride (PVDF) polymer electrolyte is a promising candidate as it can potentially provide a high voltage window and enable high energy density solid-state batteries. However, the current PVDF-based polymer electrolyte is still not compatible with high voltage cathodes, such as layered lithium transition metal oxides and the interaction between the salt and PVDF polymer has not been fully elucidated. We have systematically studied the PVDF-based electrolytes with different salts and salt combinations, including lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and lithium bis(pentafluoroethanesulfonyl)imide (LiBETI). The optimized electrolyte delivers excellent performance for solid-state Li||LiFePO4 cells, achieving a specific capacity of over 150 mAh/g and lasting more than 50 cycles with over 99% capacity retention. Similar tests have also been applied to lithium nickel manganese cobalt oxides (NMC), and the preliminary results show promising cycling stability and capacity retention. In addition to electrochemical study, we employed a range of synchrotron-based X-ray techniques, including diffraction, pair distribution function analysis, and absorption spectroscopy, to investigate the interactions between the polymer and lithium salt in the polymer electrolytes. This knowledge will provide valuable information for designing new polymer electrolyte systems. Acknowledgments: The work at Brookhaven National Laboratory was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Vehicle Technology Office of the U.S. Department of Energy through the Advanced Battery Materials Research (BMR) Program under contract DE-SC0012704. This research used beamline 23-ID-2 and 28-ID-2 of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704.

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32

Osaka, Noboru, Yuichi Minematsu e Masatoshi Tosaka. "Influence of lithium salt-induced phase separation on thermal behaviors of poly(vinylidene fluoride)/ionic liquid gels and pore/void formation by competition with crystallization". RSC Advances 8, n. 71 (2018): 40570–80. http://dx.doi.org/10.1039/c8ra08514e.

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33

Hsu, Chang-Yu, Ren-Jun Liu, Chun-Han Hsu e Ping-Lin Kuo. "High thermal and electrochemical stability of PVDF-graft-PAN copolymer hybrid PEO membrane for safety reinforced lithium-ion battery". RSC Advances 6, n. 22 (2016): 18082–88. http://dx.doi.org/10.1039/c5ra26345j.

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34

Li, Haijuan, Ling Li, Shuaizhi Zheng, Xinming Wang e Zengsheng Ma. "High Temperature Resistant Separator of PVDF-HFP/DBP/C-TiO2 for Lithium-Ion Batteries". Materials 12, n. 17 (2 settembre 2019): 2813. http://dx.doi.org/10.3390/ma12172813.

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Abstract (sommario):

To improve the thermal shrinkage and ionic conductivity of the separator for lithium-ion batteries, adding carboxylic titanium dioxide nanofiber materials into the matrix is proposed as an effective strategy. In this regard, a poly(vinylidene fluoride-hexafluoro propylene)/dibutyl phthalate/carboxylic titanium dioxide (PVDF-HFP/DBP/C-TiO2) composite separator is prepared with the phase inversion method. When the content of TiO2 nanofibers reaches 5%, the electrochemical performance of the battery and ion conductivity of the separator are optimal. The PVDF-HFP/DBP/C-TiO2 (5%) composite separator shows about 55.5% of porosity and 277.9% of electrolyte uptake. The PVDF-HFP/DBP/C-TiO2 (5%) composite separator has a superior ionic conductivity of 1.26 × 10 −3 S cm−1 and lower interface impedance at room temperature, which brings about better cycle and rate performance. In addition, the cell assembled with a PVDF-HFP/DBP/C-TiO2 separator can be charged or discharged normally and has an outstanding discharge capacity of about 150 mAh g−1 at 110 °C. The battery assembled with the PVDF-HFP/DBP/C-TiO2 composite separator exhibits excellent electrochemical performance under high and room temperature environments.

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35

Zhu, Chun Liu, Can Tao, Jun Jie Bao, Yi Ping Huang e Ge Wen Xu. "Waterborne Polyurethane Used as Binders for Lithium-Ion Battery with Improved Electrochemical Properties". Advanced Materials Research 1090 (febbraio 2015): 199–204. http://dx.doi.org/10.4028/www.scientific.net/amr.1090.199.

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Abstract (sommario):

LiFePO4based Lithium-ion batteries are prepared by nonionic waterborne polyurethane with different soft segments which act as binder. FTIR is used to characterize the structure of waterborne polyurethanes .The emulsion viscosity, mechanical properties of films are measured. The result shows that, the emulsion viscosity and tensile strength of polyurethane based polyether glycol are smaller than polyurethane based polyester. Charge-discharge, cycle performance and AC impedance spectroscopy measurement indicat that the first charge-discharge efficiency is 92%, the biggest discharge capacity is 115 mAh/g for lithium-ion batteries based on waterborne polyurethane as adhesive which equaled to PVDF, the batteries have a good cycle performance and high cycle efficiency and the impedance of batteries are small than PVDF.

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36

Liang, Xinghua, Yu Zhang, Yujuan Ning, Dongxue Huang, Linxiao Lan e Siying Li. "Quasi-Solid-State Lithium-Sulfur Batteries Assembled by Composite Polymer Electrolyte and Nitrogen Doped Porous Carbon Fiber Composite Cathode". Nanomaterials 12, n. 15 (29 luglio 2022): 2614. http://dx.doi.org/10.3390/nano12152614.

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Abstract (sommario):

Solid-state lithium sulfur batteries are becoming a breakthrough technology for energy storage systems due to their low cost of sulfur, high energy density and high level of safety. However, its commercial application has been limited by the poor ionic conductivity and sulfur shuttle effect. In this paper, a nitrogen-doped porous carbon fiber (NPCNF) active material was prepared by template method as a sulfur-host of the positive sulfur electrode. The morphology was nano fiber-like and enabled high sulfur content (62.9 wt%). A solid electrolyte membrane (PVDF/LiClO4/LATP) containing polyvinylidene fluoride (PVDF) and lithium aluminum titanium phosphate (Li1.3Al0.3Ti1.7(PO4)3) was prepared by pouring and the thermosetting method. The ionic conductivity of PVDF/LiClO4/LATP was 8.07 × 10−5 S cm−1 at 25 °C. The assembled battery showed good electrochemical performance. At 25 °C and 0.5 C, the first discharge specific capacity was 620.52 mAh g−1. After 500 cycles, the capacity decay rate of each cycle was only 0.139%. The synergistic effect between the composite solid electrolyte and the nitrogen-doped porous carbon fiber composite sulfur anode studied in this paper may reveal new approaches for improving the cycling performance of a solid-state lithium-sulfur battery.

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37

Kulova, Tatiana L., Sergey A. Li, Evgeniya V. Ryzhikova e Alexander M. Skundin. "The binder influence on the performance of positive electrodes of lithium-sulfur batteries". Electrochemical Energetics 21, n. 3 (24 settembre 2021): 151–55. http://dx.doi.org/10.18500/1608-4039-2021-21-3-151-155.

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Abstract (sommario):

The comparison of performance of positive electrodes of lithium-sulfur batteries made using the binders based on fluoroplastic (PVDF Solef 5310 and Kynar) and polyethylene oxide (PEO) was carried out. The electrodes made using PVDF Kynar or limited amounts of PEO were shown to have certain advantages. It was also found that electrodes with PEO had an increased specific capacity during the initial period of cycling, whereas electrodes with Kynar were characterized by the minimum capacity fading during cycling.

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38

Kulova, Tatiana L., Sergey A. Li, Evgeniya V. Ryzhikova e Alexander M. Skundin. "The binder influence on the performance of positive electrodes of lithium-sulfur batteries". Electrochemical Energetics 21, n. 3 (24 settembre 2021): 151–55. http://dx.doi.org/10.18500/1608-4039-2021-21-3-151-155.

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Abstract (sommario):

The comparison of performance of positive electrodes of lithium-sulfur batteries made using the binders based on fluoroplastic (PVDF Solef 5310 and Kynar) and polyethylene oxide (PEO) was carried out. The electrodes made using PVDF Kynar or limited amounts of PEO were shown to have certain advantages. It was also found that electrodes with PEO had an increased specific capacity during the initial period of cycling, whereas electrodes with Kynar were characterized by the minimum capacity fading during cycling.

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39

Liang, Xinghua, Yujuan Ning, Linxiao Lan, Guanhua Yang, Minghua Li, Shufang Tang e Jianling Huang. "Electrochemical Performance of a PVDF-HFP-LiClO4-Li6.4La3.0Zr1.4Ta0.6O12 Composite Solid Electrolyte at Different Temperatures". Nanomaterials 12, n. 19 (28 settembre 2022): 3390. http://dx.doi.org/10.3390/nano12193390.

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Abstract (sommario):

The stability and wide temperature performance range of solid electrolytes are the keys to the development of high-energy density all-solid-state lithium-ion batteries. In this work, a PVDF-HFP-LiClO4-Li6.4La3Zr1.4Ta0.6O12 (LLZTO) composite solid electrolyte was prepared using the solution pouring method. The PVDF-HFP-LiClO4-LLZTO composite solid electrolyte shows excellent electrochemical performance in the temperature range of 30 to 60 °C. By assembling this electrolyte into the battery, the LiFePO4/PVDF-HFP-LiClO4-LLZTO/Li battery shows outstanding electrochemical performance in the temperature range of 30 to 60 °C. The ionic conductivity of the composite electrolyte membrane at 30 °C and 60 °C is 5.5 × 10−5 S cm−1 and 1.0 × 10−5 S cm−1, respectively. At a current density of 0.2 C, the LiFePO4/PVDF-HFP-LiClO4-LLZTO/Li battery shows a high initial specific discharge capacity of 133.3 and 167.2 mAh g−1 at 30 °C and 60 °C, respectively. After 50 cycles, the reversible electrochemical capacity of the battery is 121.5 and 154.6 mAh g−1 at 30 °C and 60 °C; the corresponding capacity retention rates are 91.2% and 92.5%, respectively. Therefore, this work provides an effective strategy for the design and preparation of solid-state lithium-ion batteries.

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40

Xie, Manman, Xia Feng, Juncheng Hu, Zhengyi Liu, Zijian Wang, Li Chen e Yiping Zhao. "Preparation and characterization of anti-fouling PVDF membrane modified by chitin". Journal of Polymer Engineering 37, n. 3 (1 marzo 2017): 313–21. http://dx.doi.org/10.1515/polyeng-2015-0532.

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Abstract (sommario):

Abstract Poly(vinylidene fluoride) (PVDF)/chitin (CH) blend membranes were prepared via the method of immersion-precipitation phase transformation with the solvent system N,N-dimethylacetamide (DMAc)/lithium chloride (LiCl) as solvent and water as coagulant. The effect of CH on membrane structure and performance was investigated. Owing to the strong hydrophilicity, CH chains enriched on the blend membrane surface and improved the hydrophilicity of the membrane. The addition of CH also led to the formation of finger-like pores and the increase of pore size and porosity. The flux and the flux recovery ratio (FRR) of the blend membrane were higher than that of pure PVDF membrane. The fouling resistance of the blend membrane was lower than that of PVDF original membrane. In a word, the addition of CH to PVDF membrane improved the hydrophilicity and the anti-fouling ability of PVDF membrane.

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41

Jo, Mun Hui, Jun Hwan Kim e Soon Ki Jeong. "Effects of Poly(Vinylidene Fluoride) Content on Electrochemical Properties of a Graphite Negative Electrode in Lithium Secondary Batteries". Key Engineering Materials 724 (dicembre 2016): 92–96. http://dx.doi.org/10.4028/www.scientific.net/kem.724.92.

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Abstract (sommario):

We investigated the effect of poly (vinylidene fluoride) (PVdF) binder content on graphite negative electrodes for lithium secondary batteries. The negative electrode was prepared by artificial graphite powder and poly (vinylidene fluoride) binder. Scanning electron microscopy, charge/discharge test, and electrochemical impedance microscopy were conducted. As a result of electrochemical analysis, we confirmed that the electrochemical behavior varied according to the PVdF content (5, 10, 15, 50, and 90 wt%). In addition, charge/discharge test and electrochemical impedance microscopy results showed the high irreversible capacities and resistances, observed for electrodes containing PVdF contents of 50 and 90 wt%. This demonstrated that decomposition of the binder was generated during electrochemical analysis.

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42

Siekierka, Anna, e Marek Bryjak. "Modified Poly(vinylidene fluoride) by Diethylenetriamine as a Supported Anion Exchange Membrane for Lithium Salt Concentration by Hybrid Capacitive Deionization". Membranes 12, n. 2 (18 gennaio 2022): 103. http://dx.doi.org/10.3390/membranes12020103.

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Abstract (sommario):

This paper shows the investigation for the optimal anion exchange membranes (AEM) supporting the desorption step of the HCDI process. The chemical modification of PVDF by diethylene triamine created the AEM. To confirm the ion-exchange character of materials, the chemical analysis with FTIR, SEM, surface energetics, and transportation analysis were applied. Next, the investigated membranes were applied for the sorption and desorption of lithium chloride. The specific sorptive parameters were higher according to the incorporation of the nitrogen groups into polymeric chains. Considering the desorption efficiency, membranes modified by four days were selected for further evaluation. The application in the HCDI process allowed reaching the desorption efficiency at 90%. The system composed of PVDF-DETA4 membrane was suitable for sorption 30 mg/g of salt. By applying the PVDF-DETA4 membrane, it is possible to concentrate LiCl with four factors. The anion exchange character of the developed membrane was confirmed by adsorption kinetics and isotherms of chlorides, nitrates, sodium, and lithium. The prepared membrane could be considered a perspective material suitable for concentration salt with electro-driven technologies for the above reasons.

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43

Mohanty, Debabrata, Pin-Hsuan Huang e I.-Ming Hung. "Preparation and Characterization of a LiFePO4- Lithium Salt Composite Cathode for All-Solid-State Li-Metal Batteries". Batteries 9, n. 4 (20 aprile 2023): 236. http://dx.doi.org/10.3390/batteries9040236.

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Abstract (sommario):

This study develops a composite cathode material suitable for solid-state Li-ion batteries (SSLIB). The composite cathode consists of LiFePO4 as the active material, Super P and KS-4 carbon materials as the conductive agents, and LiTFSI as the lithium salt. An LiFePO4/LATP-PVDF-HFP/Li all-solid-state LIB was assembled using Li1.3Al0.3Ti1.7(PO4)3 (LATP)/ poly(vinylidenefluoride-co-hexafluoropropylene (PVDF-HFP) as the solid-state electrolyte and lithium metal as the anode. The structure of the synthesized LATP was analyzed using X-ray diffraction, and the microstructure of the composite cathode and solid electrolyte layer was observed using a field emission scanning electron microscope. The electrochemical properties of the all-solid-state LIB were analyzed using electrochemical impedance spectroscopy (EIS) and a charge–discharge test. The effect of the composition ratio of the fabricated cathode on SSLIB performance is discussed. The results reveal that the SSLIB fabricated using the cathode containing LiFePO4, Super P, KS-4, PVDF, and LiTFSI at a weight ratio of 70:10:10:7:3 (wt.%) and a LATP/PVDF-HFP solid electrolyte layer containing PVDF-HFP, LiTFSI, and LATP at a weight ratio of 22:33:45 (wt.%) exhibited the optimal performance. Particularly, the SSLIB fabricated using the cathode containing 3% LiTFSI exhibited a discharge capacity of 168.9 mAhg−1 at 0.1 C, which is close to the theoretical capacity (170 mAhg−1), and had very good stability. The findings of this study suggests that the incorporation of an appropriate amount of LiTFSI can significantly enhance the electrochemical performance of SSLIB batteries.

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Brilloni, Alessandro, Francesco Marchesini, Federico Poli, Elisabetta Petri e Francesca Soavi. "Performance Comparison of LMNO Cathodes Produced with Pullulan or PEDOT:PSS Water-Processable Binders". Energies 15, n. 7 (2 aprile 2022): 2608. http://dx.doi.org/10.3390/en15072608.

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Abstract (sommario):

The aim of this paper is to demonstrate lithium metal battery cells assembled with high potential cathodes produced by sustainable processes. Specifically, LiNi0.5Mn1.5O4 (LMNO) electrodes were fabricated using two different water-processable binders: pullulan (PU) or the bifunctional electronically conductive poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS). The cell performance was evaluated by voltammetric and galvanostatic charge/discharge cycles at different C-rates with 1M LiPF6 in 1:1 (v:v) ethylene carbonate (EC):dimethyl carbonate (DMC) (LP30) electrolyte and compared to that of cells assembled with LMNO featuring poly(vinylidene difluoride) (PVdF). At C/10, the specific capacity of LMNO-PEDOT:PSS and LMNO-PU were, respectively, 130 mAh g−1 and 127 mAh g−1, slightly higher than that of LMNO-PVdF (124 mAh g−1). While the capacity retention at higher C-rates and under repeated cycling of LMNO-PU and LMNO-PVdF electrodes was similar, LMNO-PEDOT:PSS featured superior performance. Indeed, lithium metal cells assembled with PEDOT:PSS featured a capacity retention of 100% over 200 cycles carried out at C/1 and with a high cut-off voltage of 5 V. Overall, this work demonstrates that both the water-processable binders are a valuable alternative to PVdF. In addition, the use of PEDOT:PSS significantly improves the cycle life of the cell, even when high-voltage cathodes are used, therefore demonstrating the feasibility of the production of a green lithium metal battery that can exhibit a specific energy of 400 Wh kg−1, evaluated at the electrode material level. Our work further demonstrates the importance of the use of functional binders in electrode manufacturing.

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Zhai, Yunyun, Na Wang, Xue Mao, Yang Si, Jianyong Yu, Salem S. Al-Deyab, Mohamed El-Newehy e Bin Ding. "Sandwich-structured PVdF/PMIA/PVdF nanofibrous separators with robust mechanical strength and thermal stability for lithium ion batteries". J. Mater. Chem. A 2, n. 35 (2014): 14511–18. http://dx.doi.org/10.1039/c4ta02151g.

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46

Ou, Yun, Chaoyong Ma, Zhiyong Tang, Chenqi Yao, Yunzhuo Zhao e Juanjuan Cheng. "Fe3O4-PVDF Composite Network for Dendrite-Free Lithium Metal Batteries". Nanomaterials 13, n. 20 (17 ottobre 2023): 2782. http://dx.doi.org/10.3390/nano13202782.

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Abstract (sommario):

Dendrite growth has been the main trouble preventing the practical application of Li metal anodes. Herein, we present how an Fe3O4-PVDF composite network prepared by using electrospinning has been designed to protect lithium metal anodes effectively. In the symmetrical cells test, the cell with the Fe3O4-PVDF composite network maintains good cycle performance after 600 h (500 cycles) at a current density of 1 mA cm−2 and a plating/stripping capacity of 1 mAh cm−2. The bulky Li dendrite is suppressed and a uniform Li deposition remains after long cycling. The characteristics of this engineered separator are further demonstrated in Li-S full cells with a good cycle performance (capacity of 419 mAh g−1 after 300 cycles at 0.5 C). This work provides a new idea for the protection of lithium metal anodes.

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47

Ade Putra, Oki, Berlian Muhammad Ilham e Hendri Widiyandari. "The Physicochemical Properties of PVDF/SiO₂ Composite Nanofibers for Potential Application of Lithium-Ion Battery Separators". Materials Science Forum 1044 (27 agosto 2021): 81–87. http://dx.doi.org/10.4028/www.scientific.net/msf.1044.81.

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Abstract (sommario):

Lithium-ion batteries have the main component include a positive electrode, negative electrode, liquid electrolyte, and membrane separator. The separator was used to secure the battery by preventing it from short circuits. In this paper, the separator PVDF/SiO2 (Polyvinylidene fluoride/Silica) nanofiber membrane was synthesized by double jet sprayers electrospinning method on rotating cylinder collector. The SiO2 colloid nanoparticle concentration was varied at 1000, 2500, and 5000 ppm. The effect of the SiO2 nanoparticle addition to the PVDF nanofiber membrane to improve membrane characteristics, including porosity, high temperature stability mechanical, mechanical strength, and battery capacity stability, were systematically investigated. The PVDF/SiO2 results have a fibrous structure with SiO2 adhering to the fibers' surface. The membrane separator's average thickness is 10.2 micrometers. A large amount of SiO2 addition (SiO2 5000 ppm) on the PVDF nanofibers membrane increased porosity, mechanical properties, and stability at a temperature of 150 °C.

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48

Berhe, Gebregziabher Brhane, Wei-Nien Su, Ljalem Hadush Abrha, Hailemariam Kassa Bezabh, Teklay Mezgebe Hagos, Tesfaye Teka Hagos, Chen-Jui Huang et al. "Garnet–PVDF composite film modified lithium manganese oxide cathode and sulfurized carbon anode from polyacrylonitrile for lithium-ion batteries". Journal of Materials Chemistry A 8, n. 28 (2020): 14043–53. http://dx.doi.org/10.1039/d0ta05392a.

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Abstract (sommario):

Composite film of polyvinylidene difluoride (PVDF) and Li_5.6Ga_0.26La_2.9Zr_1.87Nb_0.05O₁₂ garnet improves the cycling stability and rate capability of lithium manganese oxide (LMO) cathode.

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49

Sturman, James, Chae-Ho Yim, Mathieu Toupin, Zouina Karkar, Elena A. Baranova e Yaser Abu-Lebdeh. "Optimizing Aqueous Binders for Next-Generation Lithium-Ion Batteries: A Practical Approach". ECS Meeting Abstracts MA2022-02, n. 3 (9 ottobre 2022): 278. http://dx.doi.org/10.1149/ma2022-023278mtgabs.

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Abstract (sommario):

The demand for lithium-ion batteries continues to grow as the need for renewable energy increases. Over the past few decades, lithium-ion batteries have seen widespread adoption in portable electronics, and they are increasingly being used in electric vehicles. To satisfy the energy density needed for these next-generation applications, new anode materials with high-energy densities are required. Traditional graphite is a very stable intercalation-based anode, but its low capacity has driven many researchers to identify alternatives. Silicon (Si) has one of the highest gravimetric energy densities known when alloyed with lithium. Unlike graphite which is limited to 1 lithiumion per 6 carbon atoms (LiC6), the lithium-silicon alloy Li15Si4 has nearly 4 lithium ions per silicon atom. This gives silicon a theoretical capacity of 3579 mAh/g, compared to the 372 mAh/g for graphite. However, the challenge with silicon (and most alloy anodes) is its poor stability— as the alloying of lithium and silicon is accompanied with a 300% volume expansion. On a microscopic scale, this causes material/electrode swelling and pulverization, which in turn causes severe capacity fade in a few cycles. The binder is known to play an important role in the cycle stability of silicon-based anodes for lithium-ion batteries. Polyvinylidene fluoride (PVDF) has traditionally been the binder used in the preparation of both graphite anodes and lithium metal oxide cathodes. It is electrochemically stable; that is, it is not reduced at the low potential of the anode (~5 mV vs Li) and is not oxidized at the high potential of the cathode (5 V vs Li). However, PVDF has three main disadvantages. First, PVDF cannot accommodate the large volumetric expansion of silicon lithiation. As a result, batteries using PVDF as a binder with silicon will experience a very rapid drop in capacity. Second, PVDF is not water soluble and requires the use of organic solvents like N-Methyl-2-pyrrolidone (NMP) during electrode processing. Finally, the cost of PVDF is approximately 20 USD/kg, which is several times greater than competing binders like sodium carboxymethylcellulose (NaCMC) at 6 USD/kg. Next-generation binders should be inexpensive, able to accommodate the expansion of silicon, and use environmentally friendly processing. Natural biopolymers (such as NaCMC and xanthan gum XG) are a promising class of binders that offer several advantages over traditional polyvinylidene fluoride (PVDF). Biopolymers contain many carboxylate and hydroxyl functional groups which aid in the formation of noncovalent bonding with the oxide surface of silicon. In particular, xanthan gum is a high molecular weight polysaccharide produced extracellularly by the bacteria Xanthomonas campestris. It is water soluble and thus eliminates the need for organic solvents. In addition, its high molecular weight is known to provide better capacity retention, owing to the long molecular chains that can accommodate silicon expansion. While existing studies have explored the fundamental properties of these biopolymer binders and their interaction with silicon, there has been little research on the use of these binders under realistic processing conditions (≤ 10 wt% binder). Herein, we optimize the electrochemical performance of both NaCMC and XG-based silicon electrodes with a low binder content. In addition, we report results for both a high-silicon (≥80 wt%) and a practical low-silicon (20 wt%) composite, all while using nano silicon prepared by industrial-scale synthesis. Figure 1 below shows the capacity retention of different electrode preparations. A higher initial capacity is expected with 80% silicon. However, the overall stability is superior for the low silicon-high graphite (G) composites. Keywords: high-capacity anodes; binders; biopolymers; silicon; lithium-ion batteries Figure 1. Capacity vs cycle number for 1st Generation Si-based electrodes. Cycled at C/10. References H. Yim, S. Niketic, N. Salem, O. Naboka, and Y. Abu-Lebdeh, J. Electrochem. Soc., 164, A6294–A6302 (2017). Zhao, S. Niketic, C. H. Yim, J. Zhou, J. Wang, and Y. Abu-Lebdeh, ACS Omega, 3, 11684–11690 (2018). M. Courtel and Y. Abu-Lebdeh, “Use of Xanthan Gum as an Anode Binder,” Patent 10,483,546 B2, 2019. Li, Z. G. Wu, Y. M. Liu, Z. W. Yang, G. K. Wang, Y. X. Liu, Y. J. Zhong, Y. Song, B. H. Zhong, and X. D. Guo, Ionics (Kiel)., 27, 1829–1836 (2021). Figure 1

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Xu, Peijie, Xiaoyun Yan, Yi Zhou, Chunyuan Wang, Hongfei Cheng e Yihe Zhang. "High-performance composite separators based on the synergy of vermiculite and laponite for lithium-ion batteries". Soft Matter 18, n. 13 (2022): 2522–27. http://dx.doi.org/10.1039/d1sm01772a.

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A series of PVDF/V/L composite separators are fabricated by using phase inversion method. The PVDF/V5/L5 has a coulombic efficiency of 99.5% after 100 cycles and a high capacity retention rate of 98.4%, which shows excellent rate performance.

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