Статті в журналах: "LiMn204"

1

Song, Jie, Bing Xu, De Xin Huang, Cai Xia Li, and Qiang Li. "Synthesis, Structure and Properties of Super Fine LiMn₂O₄." Advanced Materials Research 177 (December 2010): 9–11. http://dx.doi.org/10.4028/www.scientific.net/amr.177.9.

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In this paper, super fine LiMn2O4 powder was synthesized by mechanochemical method starting from Li2CO3 and Mn2O3. The structure, size and morphology of LiMn2O4 were explored with X-ray diffraction and scanning electron microscopy (SEM). The electrochemical properties of LiMn2O4 were studied in 2 mol/L (NH4)2SO4 solution. The result showed that pure spinel LiMn204 powder was prepared after 8h grinding with 3.0KW of power and the particle size was about 1µm. Cyclic vohammetry curve indicate LiMn2O4 electrode material has better capacitive performances.

2

Chen, Mi Mi, Xian Yan Zhou, Xiang Zhong Huang, Mei Huang, Chang Wei Su, Jun Ming Guo, and Ying Jie Zhang. "Preparation and Characterization of LiMn_2-xMg_xO₄ by Low-Temperature Flameless Solution Combustion Synthesis." Advanced Materials Research 581-582 (October 2012): 611–15. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.611.

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The spinel Mg-doped LiMn2-xMgxO4（0≤x≤0.10）lithium ion cathode material was prepared by LiNO3, Mn(Ac)2.4H2O and Mg(Ac)2.4H2O by a low-temperature flameless solution combustion at 400°C, and HNO3 was used as oxidant. The results showed that the crystallinity of prepared material was superior to the pure LiMn2O4, and this method was better than traditional solid-state method. The particle sizes of the Mg-doped spinel LiMn2-xMgxO4 decreased with the increase of Mg doping, and the particle sizes were 50 to 90 nm; the crystal lattice interface was clear. The original capacities of Mg-doped were lower than that of undoped LiMn2O4 (109.2 mAh/g) excepts for x(Mg)=0.04, original capacity of which was 128mAh/g. However, the rentions of all the doped spinels were higher than that of undoped spinel.

3

Abou-Sekkina, Morsi, Fawaz Saad, Fouad El-Metwaly та Abdalla Khedr. "Synthesis, characterization, DC-electrical conductivity and γ-ray effect on Ag1+, Y3+ double doped nano lithium manganates (LiMn2−2x AgxYxO4) for rechargeable batteries". Materials Science-Poland 32, № 3 (1 вересня 2014): 315–23. http://dx.doi.org/10.2478/s13536-014-0205-1.

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AbstractPristine lithium manganate (LiMn2O4) and Ag1+, Y3+ double doped nano lithium manganate [LiMn2−2x AgxYxO4, (x = 0.025, 0.05)] spinels were synthesized via a coprecipitation method for rechargeable batteries applications. The synthesized LiMn1.9Ag0.05Y0.05O4 was exposed to different doses of γ-irradiation (10 and 30 kGy). The resulting spinel products were characterized by using thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), electronic (UV-Vis) and electron spin resonance (ESR) spectra. LiMn2O4 exhibited a discharge capacity of 124 mAhg−1 while LiMn1.9Ag0.05Y0.05O4 had discharge capacities of 129 and 137 mAhg−1 for non irradiated and γ-irradiated (30 kGy) samples, respectively. The effects of the dopant cations and γ-irradiation on the discharge capacity and DC-electrical conductivity of some synthesized spinels were studied.

4

Zhang, Ligong, Yurong Zhang, and Xuehong Yuan. "Enhanced high-temperature performances of LiMn2O4 cathode by LiMnPO4 coating." Ionics 21, no. 1 (June 8, 2014): 37–41. http://dx.doi.org/10.1007/s11581-014-1169-1.

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5

Singh, Priti, Anjan Sil, Mala Nath, and Subrata Ray. "Preparation and Characterization of Li [Mn_2-xFe_x]O₄ (x = 0.0-0.6) Spinel Nanoparticles as Cathode Materials for Lithium Ion Battery." Advanced Materials Research 67 (April 2009): 233–38. http://dx.doi.org/10.4028/www.scientific.net/amr.67.233.

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Nanosized powders in the system LiMn2−xFexO4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) have been synthesized by sol-gel technique using citric acid as chelating agent. The effect of Fe substitution on the structure and surface morphology of spinel LiMn2O4 has been examined by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and Electrochemical characteristics. The materials for all the compositions except x = 0.6 exhibit a phase pure cubic spinel structure as evident from the XRD analyses. Doping with Fe increases the crystallinity in the materials and decreases the average particle size. The surface morphology of the synthesized particles is spherical and polygonal type. Average particle size lies in the range of 60 to 400 nm. Improved capacity retention in rechargeable 4 V Li/LiMn2-xFexO4 cells has been observed when a small amount of manganese in the spinel cathode is replaced with iron. The first discharge capacities of LiMn2−xFexO4 (x = 0.0, 0.1, 0.2, 0.3) in a voltage range of 3 V to 4.3 V decreases as the x increases, however, the cyclic performance improves.

6

Ikuhara, Yumi H., Yuji Iwamoto, Koichi Kikuta, and Shin-ichi Hirano. "Processing of epitaxial LiMn2O4 thin film on MgO(110) through metalorganic precursor." Journal of Materials Research 15, no. 12 (December 2000): 2750–57. http://dx.doi.org/10.1557/jmr.2000.0394.

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Epitaxial LiMn2O4 was successfully synthesized by coating a [Li–Mn–O] metalorganic precursor solution onto MgO (110) substrates at temperatures as low as 350 °C. Cross-sectional transmission electron microscopy observation revealed that the orientation relationship between LiMn2O4 and MgO was (111) LiMn2O4 //(111) MgO, (110) LiMn2O4 //(110) MgO, and [112] LiMn2O4 //[112] MgO, which resulted in the (111) LiMn2O4 planes growing perpendicular to the surface plane of MgO. The interface structure consisted of (111) layers of Mn atoms in the LiMn2O4 crystal aligned with the Mg atoms in the (111) planes of the MgO substrate when viewed along the [112] direction.

7

Kaiya, Hiroyuki, Shinya Suzuki, and Masaru Miyayama. "Effects of Lattice Defects on Cathode Properties of LiMn₂O₄Synthesized at Low Temperatures for Lithium Ion Secondary Battery." Key Engineering Materials 388 (September 2008): 41–44. http://dx.doi.org/10.4028/www.scientific.net/kem.388.41.

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Effects of lattice defects on cathode properties of LiMn2O4 synthesized at low temperatures were investigated. LiMn2O4 powders were synthesized by a sol-gel method. The specific capacities of LiMn2O4 decreased from 134 to 81 mAh g-1 with decreasing heating temperature from 750 to 200°C. X-ray absorption spectroscopy showed that a large amount of lattice defects such as cation vacancies existed and cation mixing occurred in LiMn2O4 calcined at low temperatures. It was found that the low specific capacities of LiMn2O4 calcined at low temperatures were attributed to these lattice defects.

8

Simatupang, Martinus, Lia Asri, and Bambang Sunendar Purwasasmita. "PENGARUH PENAMBAHAN KITOSAN DAN ASAM SITRAT TERHADAP PEMBENTUKAN LiMn2O4 SPINEL MENGGUNAKAN METODE SOL-GEL." Jurnal Teknologi Bahan dan Barang Teknik 5, no. 2 (December 31, 2015): 61. http://dx.doi.org/10.37209/jtbbt.v5i2.60.

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LiMn2O4 spinel banyak dikembangkan untuk katoda dalam baterai lithium karena memiliki kerapatan energi yang tinggi. Dalam penelitian ini, LiMn2O4 spinel disintesis menggunakan metode sol-gel dengan kitosan dan asam sitrat sebagai senyawa pengkelat. Densifikasi dilakukan pada suhu kalsinasi 600°C. Penambahan kitosan 1% (w/v) mampu meningkatkan fraksi massa fasa LiMn2O4 spinel hingga 73,9% (w/w). Penambahan asam sitrat 0,2 M ke dalam prekursor yang mengandung kitosan tidak memberikan hasil yang signifikan terhadap pembentukan fasa LiMn2O4 spinel, namun berperan dalam mencegah aglomerasi partikel. Kondisi optimum sintesis LiMn2O4 spinel diperoleh dengan penambahan kombinasi kitosan dan asam sitrat sebagai senyawa pengkelat, menghasilkan ukuran kristalit 28 nm dan konduktivitas sebesar 9,38 x10-6 s/cm2.Kata kunci: kitosan, LiMn2O4 spinel, sol-gel, asam sitrat

9

Ikuhara, Yumi H., Xiuliang Ma, Yuji Iwamoto, Yuichi Ikuhara, Koichi Kikuta, and Shin-ichi Hirano. "Interfaces between solution-derived LiMn2O4 thin films and MgO and Au/MgO substrates." Journal of Materials Research 17, no. 2 (February 2002): 358–66. http://dx.doi.org/10.1557/jmr.2002.0051.

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Spinel LiMn2O4 thin films have been prepared on MgO(110) and Au/MgO(110) substrates by a chemical solution deposition method. The interfaces between film and substrate were characterized by means of high-resolution transmission electron microscopy (HREM) as well as x-ray diffraction. Cross-sectional HREM observation revealed that LiMn2O4 films grew epitaxially on the MgO(110) and Au/MgO(110) substrates. In the LiMn2O4/MgO system, misfit dislocations formed to accommodate the lattice strain at the LiMn2O4/MgO interface. In the LiMn2O4/Au/MgO system, Au grew epitaxially on the MgO substrate with its surface facetted along {111} planes, probably because the surface energy of this plane is relatively low. The formation of these facets is considered to have a favorable effect on the growth of {111} planes of LiMn2O4 when deposited on the Au film.

10

Guo, Jun Ming, Gui Yang Liu, Jie Liu, De Wei Guo, Ke Xin Chen, and He Ping Zhou. "Effects of Fuel Content and Calcination Procedure on Phase Composition and Microstructure of LiMn₂O₄ Prepared by Solution Combustion Synthesis." Key Engineering Materials 368-372 (February 2008): 296–98. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.296.

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Spinel LiMn2O4 was prepared by solution combustion synthesis. The effect of fuel content and calcination procedure on phase composition and microscopic structure of LiMn2O4 was studied. X-ray diffraction patterns showed that fuel content had no obvious influence on the grain size and phase purity of LiMn2O4. Higher calcination temperature led to higher phase purity, lager grain size, and better crystallization of resultant LiMn2O4. Below 600°C the effect of calcination time was inconspicuous, which became notable above 700°C. Scanning electron microscope images showed that nanocrystalline LiMn2O4 was obtained when the calcination temperature was lower than 600°C and the grain size increased at higher temperatures.

11

Hosono, Eiji, Hirofumi Matsuda, Masashi Okubo, Tetsuiichi Kudo, Shinobu Fujihara, Itaru Honma, and Hao Shen Zhou. "Development of Positive Electrode Materials for the High Rate Lithium Ion Battery by Nanostructure Control." Key Engineering Materials 445 (July 2010): 109–12. http://dx.doi.org/10.4028/www.scientific.net/kem.445.109.

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Previously, we reported the fabrication of Na0.44MnO2 and LiMn2O4 single crystalline nanowire structure. Moreover, these electrodes showed good high rate property as lithium ion battery, because the nanostructure electrode is suitable for high rate lithium ion battery. Especially, the fabrication of LiMn2O4 single crystalline nanowire was very interesting results because the synthesis of 1-dimesional single crystal structure of LiMn2O4 is very difficult based on cubic crystal structure without anisotropic structure. The LiMn2O4 single crystalline nanowire was obtained thorough the self template method using Na0.44MnO2 nanowire. In this paper, we report the fabrication of Na0.44MnO2 and LiMn2O4 single crystalline nanowire structure and the property of lithium ion battery as review paper.

12

Kozawa, Takahiro, Toshiya Harata, and Makio Naito. "Fabrication of an LiMn2O4@LiMnPO4 composite cathode for improved cycling performance at high temperatures." Journal of Asian Ceramic Societies 8, no. 2 (March 17, 2020): 309–17. http://dx.doi.org/10.1080/21870764.2020.1743413.

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13

Mahesh, K. C., and G. S. Suresh. "Electrochemical Characterization of Graphene–LiMn2O4 Composite Cathode Material for Aqueous Rechargeable Lithium Batteries." Journal of University of Shanghai for Science and Technology 23, no. 09 (September 20, 2021): 967–80. http://dx.doi.org/10.51201/jusst/21/09636.

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A series of graphene– LiMn2O4 composite electrodes were prepared by physical mixing of graphene powder and LiMn2O4 cathode material. LiMn2O4was synthesized by reactions under autogenic pressure at elevated temperature method. CV, galvanostatic charge-discharge experiments and EIS studies revealed that the addition of graphene significantly decreases the charge-transfer resistance of LiMn2O4 electrodes. 5 wt. % graphene–LiMn2O4 composite electrode exhibits better electrochemical performance by increasing the reaction reversibility and capacity compared to that of the pristine LiMn2O4 electrode. Improved electrochemical performances are thus achieved, owing to the synergic effect between graphene and the LiMn2O4 active nanoparticles. The ultrathin flexible graphene layers can provide a support for anchoring well-dispersed active cathode particles and work as a highly conductive matrix for enabling good contact between them. At the same time, the anchoring of active nanoparticles on graphene effectively reduces the degree of restacking of graphene sheets and consequently keeps a highly active surface area which increases the lithium storage capacity and cycling performance.

14

Purwaningsih, Dyah, Roto Roto, Narsito, and Hari Sutrisno. "Preparation of LiMn₂O₄ Microstructure by Low Temperature Solid-State Reaction for Cathode Material." Advanced Materials Research 1101 (April 2015): 134–37. http://dx.doi.org/10.4028/www.scientific.net/amr.1101.134.

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This study aims at investigating a better condition of calcination at different temperature to produce LiMn2O4 microstructure. In this study, cubic LiMn2O4 was synthesized using a low temperature solid-state reaction. We report, here, MnO2 nanorods synthesis by reflux and their chemical conversion to LiMn2O4. The compound was characterized by XRD and TEM. Further, the analysis of LiMn2O4 microstructure was carried out by Direct Method using winPLOTR package program and Diamond using XRD data. At low calcination temperature, Mn2O3 is present as an impurity, but it disappears along with the increase in calcination temperature. It is also found that solid state reaction at is 750oC give nanoLiMn2O4. The lattice parameters and cell volumes of LiMn2O4 increases with the increase in heating temperature.

15

Yang, Chi. "The Electrochemical Behavior of Surface Modified Spinel LiMn₂O₄." Advanced Materials Research 538-541 (June 2012): 269–75. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.269.

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Spinel LiMn2O4 is treated on its surface with CoO1+x/ZrO2 in this paper. Metal oxide-coated spinel LiMn2O4 was investigated with respect to electrochemical characteristics. The metal oxide coating process was carried out by using the solution method. CoO1+x/ZrO2-coated spinel LiMn2O4 exhibited stable cyclic performance in the range from 3.0 to 4.4V, and it has less electrochemical impedance, polarization and capacity loss. The cell composed of the CoO1+x/ZrO2-coated spinel LiMn2O4 can be discharged at a large current density.

16

Lee, Jae Ho, Young Jae Kim, Hee Soo Moon, and Jong Wan Park. "Characteristics of SnO_x-Coated Lithium Manganese Oxide Thin Film for MEMS Power System." Materials Science Forum 486-487 (June 2005): 562–65. http://dx.doi.org/10.4028/www.scientific.net/msf.486-487.562.

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We prepared spinel-phase LiMn2O4 layer by using rf magnetron sputtering system. LiMn2O4 films were deposited at room temperature and then annealed at 750°C for crystallization to spinel type. In order to reduce the interface reaction such as Mn dissolution phenomenon during operation, we introduced SnOx (coating-layer) thin film. The SnOx films were deposited on LiMn2O4 films by rf magnetron sputtering system. A SnOx-coated LiMn2O4 film was more stable during the chargingdischarging reaction and maintained good cycle behavior at high temperature conditions of 55°C.

17

Liu, Shuai, Yun Ze Long, Hong Di Zhang, Bin Sun, Cheng Chun Tang, Hong Liang Li, Guang Wei Kan, and Chao Wang. "Preparation and Electrochemical Properties of LiMn₂O₄ Nanofibers via Electrospinning for Lithium Ion Batteries." Advanced Materials Research 562-564 (August 2012): 799–802. http://dx.doi.org/10.4028/www.scientific.net/amr.562-564.799.

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LiMn2O4 nanofibers were prepared via electrospinning and followed by calcination. The surface morphology of as-spun and pure LiMn2O4 nanofibers was characterized by a scanning electron microscope (SEM) with an average diameter of 180 nm. After calcination at 800 °C in air for 5 h, charge/discharge capacity of pure LiMn2O4 nanofibers was measured in the potential range of 3.0 to 4.3 V. Battery testing showed that LiMn2O4 have a high discharge capacity of 80 mAh/g and 85% of the initial charge capacity was maintained for 5 cycles.

18

Moon, Hee Soo, Jae Hun Yang, Jae Ho Lee, Seung Ho Ahn, and Jong Wan Park. "The Effect of SnO_x as the Protective Layer for the Lithium Manganese Oxide Thin Film." Solid State Phenomena 124-126 (June 2007): 1047–50. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.1047.

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Lithium manganese oxide (LiMn2O4) had been a promising material for lithium-ion and thin film batteries. However, the LiMn2O4 had some problems such as the manganese dissolution into liquid electrolyte. In order to improve cycleability, we introduced SnOx layer as protective layer. This layer was deposited on spinel LiMn2O4 by using radio frequency magnetron sputtering. The deposited SnOx layer fully covered the LiMn2O4 , and didn’t make a change the crystallinity of the spinel films. The SnOx layer prevented direct contact of liquid electrolyte and improved the cycle retention.

19

Lu, Chung-Hsin, and Shang-Wei Lin. "Dissolution Kinetics of Spinel Lithium Manganate and its Relation to Capacity Fading in Lithium Ion Batteries." Journal of Materials Research 17, no. 6 (June 2002): 1476–81. http://dx.doi.org/10.1557/jmr.2002.0219.

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The dissolution behavior and kinetics of spinel lithium manganate LiMn2O4 with different particle sizes have been investigated in this study. The dissolution of manganese cations from LiMn2O4 is confirmed to occur when LiMn2O4 particles are immersed in the electrolytes. The amount of dissolved manganese ions markedly increases with a rise in temperature and a decrease in particle size, which implies that the capacity fading of LiMn2O4 at elevated temperatures is associated with manganese dissolution. On the basis of the isothermal analysis of reaction kinetics, the rate of manganese dissolution from LiMn2O4 is dominated by the rate of dissolution reaction. Smaller particles exhibit a larger reaction rate constant and higher activation energy of the dissolution process than the larger ones. Therefore, an increase in temperature has a more pronounced effect on the dissolution reaction of small particles than on that of large particles.

20

Wang, Hai Quan, Zhi Qiang Hu, Kun Yang, Yang Yu, Jing Xiao Liu, Hong Shun Hao, and Hua Liu. "Electrochemical Characteristics of the Magnesium Titanium Composite Oxide-Coated Spinel-Type Lithium Manganese Oxide." Key Engineering Materials 591 (November 2013): 236–39. http://dx.doi.org/10.4028/www.scientific.net/kem.591.236.

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In this experiment, the spinel-type lithium manganese oxide (LiMn2O4) prepared via solid-phase sintering method was coated with magnesium titanium composite oxide (MgTiOx) in the presence of polyvinyl pyrrolidone (PVP) under the ultrasonic wave. The crystal structures, surface morphologies and electrochemical properties of the sample prepared were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical analysis. The X-ray diffractions indicated that the LiMn2O4 coated with MgTiOx were similar to that of the pure LiMn2O4, and they both showed sharp and high peaks. The particles of the samples prepared with PVP did not aggregate obviously, and the samples were coated completely and homogeneously. At charge-discharge rates of 0.2C, the first discharge capacity can reach more than 120 mAh / g. Compared with pure LiMn2O4, the capacity attenuation of MgTiOx-coated LiMn2O4 reduced after fifty cycles, and showed good electrochemical performance.

21

Park, Hye-Jung, Sun-Min Park, Gwang-Chul Roh, and Cheong-Hwa Han. "Electrochemical Performances of LiMn2O4:Al Synthesized by Solid State Method." Journal of the Korean Ceramic Society 48, no. 6 (November 30, 2011): 531–36. http://dx.doi.org/10.4191/kcers.2011.48.6.531.

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22

Li, Shi You, Jin Liang Liu, Xiao Ling Cui, and Li Ping Mao. "Compatibilities between Lithium Bis(Oxalate)Borate-Based Electrolyte and LiFePO₄, LiMn₂O₄ or LiNi_0.5Mn_1.5O₄ Cathodes for Lithium-Ion Batteries." Advanced Materials Research 953-954 (June 2014): 1022–25. http://dx.doi.org/10.4028/www.scientific.net/amr.953-954.1022.

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Olivine-type LiFePO4 and crystal structure LiMn2O4 or LiNi0.5Mn1.5O4 are promising cathode materials for electric vehicles (EVs) applications. To find more appropriate electrolyte systems to exert the perfect electrochemical performance of LiFePO4, LiMn2O4 and LiNi0.5Mn1.5O4 cathodes, the electrochemical performances of LiBOB-ethylene carbonate (EC)/ethyl methyl carbonate (EMC)/diethyl carbonate (DEC) electrolyte are investigated in this paper. In LiFePO4/Li, LiMn2O4/Li and LiNi0.5Mn1.5O4/Li cells, this novel electrolyte exhibits several advantages, such as stable cycle performance and good rate performance. It suggests that LiBOB-EC/EMC/DEC electrolyte has good compatibility with the three kinds of cathodes, and would be an attractive electrolyte for lithium-ion batteries based upon LiFePO4, LiMn2O4 and LiNi0.5Mn1.5O4 cathodes.

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Lu, Chung-Hsin, and Yueh Lin. "Influence of the emulsification conditions on the microstructures and electrochemical characteristics of spinel lithium manganese oxide powders." Journal of Materials Research 18, no. 3 (March 2003): 552–59. http://dx.doi.org/10.1557/jmr.2003.0071.

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Lithium manganese oxide powders (LiMn2O4) with a spinel structure were synthesized via an optimized water-in-oil emulsion process. The influence of the emulsification conditions on the microstructures and physicochemical properties of LiMn2O4 powders was investigated. The phase purity of the synthesized powders significantly depends on the water-to-oil volume ratio in the emulsion. Increasing the water-to-oil ratio tends to decrease the stability of the emulsion that in turn leads to a segregation of water and oil phases. The unstable emulsion system results in the formation of an impure phase—Li2MnO3—that markedly decreases the charge and discharge capacities of the cathode materials. When water/oil volume ratio equals 1/5 or 1/10, monophasic spinel powders are formed at temperatures as low as 400 °C. In addition, decreasing the concentration of the aqueous phase substantially reduces the particle size of LiMn2O4 powders. Nanometered-LiMn2O4 powders with a particle size of 50 nm are obtained when the concentration of the aqueous phase is 1.0 M and the water-to-oil volume ratio is 1/5. Decreasing the particle size of LiMn2O4 powders was demonstrated to effectively increase the specific capacity and improve the cyclability of LiMn2O4 powders.

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Mukoyama, Izumi, Takayuki Kodera, Nobuo Ogata, and Takashi Ogihara. "Synthesis and Lithium Battery Properties of LiM(M=Fe,Al,Mg)_xMn_2-xO₄ Powders by Spray Pyrolysis." Key Engineering Materials 301 (January 2006): 167–70. http://dx.doi.org/10.4028/www.scientific.net/kem.301.167.

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LiM(M=Fe,Al,Mg)XMn2-XO4 fine powders were synthesized by the ultrasonic spray pyrolysis using metal nitrate solution. LiMn2O4 powders obtained by this method have a spherical morphology with a submicron size. XRD revealed that as-prepared powders were crystallized to spinel structure with Fd3m space group. LiM(M=Fe,Al,Mg)XMn2-XO4 showed enhanced cycling performance at room temperature. Reduced Jahn-Teller distortion of LiMn2O4 by metal doping was responsible for enhanced cycle performance of LiMn2O4.

25

Gants, Oksana Yu, Vladimir M. Kashkin, Angelina D. Yudina, Valentina O. Zhirnova, Anna S. Timonina, and Konstantin N. Nichchev. "USING OF ATOMIC LAYER DEPOSITION METHOD FOR OBTAINING THIN FILMS BASED ON LiMn2O4 AND LiFePO4." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, no. 9 (August 5, 2020): 77–81. http://dx.doi.org/10.6060/ivkkt.20206309.6177.

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An approach to the synthesis of LiFePO4 and LiMn2O4 by atomic layer deposition is proposed and successfully implemented. The main regularities of the process are revealed and the method of synthesis realization is proposed. The following reagents were proposed and used: 2,2,6,6-tetramethylheptan-3,5 - dione of manganese, oxygen, iron (II) chloride, trimethyl phosphate, water and lithium tret-butylate. Nitrogen was used as an inert gas for purging the reactor and as a carrier gas. The influence of process parameters on the synthesis of thin films based on LiFePO4 and LiMn2O4 is described. It has been established that the phase composition of the resulting films is influenced by the time of precursor release and the process temperature. It is concluded that the increase in process temperature has a positive effect on the density of thin films of LiFePO4 and LiMn2O4. The optimum deposition temperature of LiFePO4 and LiMn2O4 is 400 ºC. It was shown that it is possible to regulate the content of each element and phase composition in films based on LiFePO4 and LiMn2O4 by changing the time of precursors release. The optimal time for the release of precursors for the synthesis of LiFePO4 and LiMn2O4 is 4 s under the stated conditions. Of great importance is the time of release of oxidizing agents-4 and 6 s for the deposition of LiFePO4 and LiMn2O4, respectively. The correlation of the layer growth rate per cycle was revealed, which was 0.2 nm/cycle for the synthesis of LiFePO4. The film obtained in the process is X-ray amorphous. To obtain the crystal structure, the films were annealed in argon at a temperature of 800 ºC. The mechanism of interaction of precursors with the substrate surface is studied. The influence of substrate activation on the uniformity of film growth is revealed.

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Liu, Yun Jian, Hua Jun Guo, Xin Hai Li, and Zhi Xing Wang. "Study on the Storage Performance of Manganese Spinel Battery." Advanced Materials Research 347-353 (October 2011): 1395–98. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.1395.

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The power battery was manufactured with the commercial LiMn2O4 and graphite, and its storage performances with different charged state were studied. Structure, morphology and surface state change of the LiMn2O4 before and after storage were observed by XRD, XPS and AC technique, respectively. The result shows that the capacity recovery of LiMn2O4 stored at discharge state is best (99.2%). While that of full-charged state is worst (93.6%). The cyclic performance of LiMn2O4 stored at full-charged state is best (capacity retention ratio of 89.8% after 200 cycles), while that of before storage is 83.0%. The crystal of the spinel was destroyed after storage, and the intensity of breakage is increased with charged state increasing. The amount of soluble Mn and Li-ion migration resistance (Rf) are increased with chare state increasing, and the oxygen loss is detected.

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Zhao, Hongyuan, Dongdong Li, Yashuang Wang, Fang Li, Guifang Wang, Tingting Wu, Zhankui Wang, Yongfeng Li, and Jianxiu Su. "Sol-Gel Synthesis of Silicon-Doped Lithium Manganese Oxide with Enhanced Reversible Capacity and Cycling Stability." Materials 11, no. 8 (August 16, 2018): 1455. http://dx.doi.org/10.3390/ma11081455.

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A series of silicon-doped lithium manganese oxides were obtained via a sol-gel process. XRD characterization results indicate that the silicon-doped samples retain the spinel structure of LiMn2O4. Electrochemical tests show that introducing silicon ions into the spinel structure can have a great effect on reversible capacity and cycling stability. When cycled at 0.5 C, the optimal Si-doped LiMn2O4 can exhibit a pretty high initial capacity of 140.8 mAh g−1 with excellent retention of 91.1% after 100 cycles, which is higher than that of the LiMn2O4, LiMn1.975Si0.025O4, and LiMn1.925Si0.075O4 samples. Moreover, the optimal Si-doped LiMn2O4 can exhibit 88.3 mAh g−1 with satisfactory cycling performance at 10 C. These satisfactory results are mainly contributed by the more regular and increased MnO6 octahedra and even size distribution in the silicon-doped samples obtained by sol-gel technology.

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Huang, Mei, Yan Xia, Jun Ming Guo, and Ying Jie Zhang. "Effect of Temperature on Spinel LiMn₂O₄ by Molten-Salt Flameless Combustion Synthesis." Applied Mechanics and Materials 80-81 (July 2011): 153–57. http://dx.doi.org/10.4028/www.scientific.net/amm.80-81.153.

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Effect of calcination temperature on spinel LiMn2O4 by molten-salt flameless combustion synthesis using the lithium acetate (lithium nitrate), manganese acetate (manganese nitrate) as raw materials was studied. The structural characterization and morphology of the powder were measured by X-ray diffraction and Scanning electron microscopy. The results indicated that the main phase was LiMn2O4, which could be obtained at 400-700 °C. The product crystallinity and particle size increased with increasing calcination temperature, but the capacity and cyclic stability decreased. When LiMn2O4 was calcinated at 400 °C and 500°C, the initial specific capacity at 0.1C rate was 104.2 and 101.5 mAh·g-1, respectively. After 30 cycles, the discharge capacity retention rate was 80.4 % and 83.5 %, respectively. The performance was the worst when LiMn2O4 was calcinated at 700°C, when the initial specific capacity was only 81.9 mAh·g-1.

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Liu, Hua Kun, Guo Xiu Wang, Zaiping Guo, Jiazhao Wang, and Kosta Konstantinov. "Nanomaterials for Lithium-ion Rechargeable Batteries." Journal of Nanoscience and Nanotechnology 6, no. 1 (January 1, 2006): 1–15. http://dx.doi.org/10.1166/jnn.2006.103.

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In lithium-ion batteries, nanocrystalline intermetallic alloys, nanosized composite materials, carbon nanotubes, and nanosized transition-metal oxides are all promising new anode materials, while nanosized LiCoO2, LiFePO4, LiMn2 O4, and LiMn2O4 show higher capacity and better cycle life as cathode materials than their usual larger-particle equivalents. The addition of nanosized metal-oxide powders to polymer electrolyte improves the performance of the polymer electrolyte for all solid-state lithium rechargeable batteries. To meet the challenge of global warming, a new generation of lithium rechargeable batteries with excellent safety, reliability, and cycling life is needed, i.e., not only for applications in consumer electronics, but especially for clean energy storage and for use in hybrid electric vehicles and aerospace. Nanomaterials and nanotechnologies can lead to a new generation of lithium secondary batteries. The aim of this paper is to review the recent developments on nanomaterials and nanotechniques used for anode, cathode, and electrolyte materials, the impact of nanomaterials on the performance of lithium batteries, and the modes of action of the nanomaterials in lithium rechargeable batteries.

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Bai, Ying, Chuan Wu, Feng Wu, Bo Rong Wu, and Shi Chen. "Electrochemical Studies on Al₂O₃-Coated Spinel LiMn₂O₄ for Lithium Ion Batteries." Materials Science Forum 675-677 (February 2011): 37–40. http://dx.doi.org/10.4028/www.scientific.net/msf.675-677.37.

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Spinel LiMn2O4 was synthesized via a solid state reaction, and modified with Al2O3 thin layers by a chemical deposition method. The electrochemical performances of the as-prepared samples were investigated with cyclic voltammetry (CV) and charge-discharge test. It is found that the Al2O3-coated LiMn2O4 help dramatically retaining the discharge capacity upon long-term cycling. The influences of the heat-treating temperature and the coating amount are discussed and compared. The optimized sample is 1% Al2O3/ LiMn2O4 heat-treated at 500oC, which has an initial discharge capacity of 116mAh/g, and a very slight capacity loss of 1.7% at the 50th cycle.

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Balakrishnan, T., N. Sankara Subramanian, and A. Kathalingam. "Studies on rheological, structural, optical, electrical and surface properties of LiMn2O4 thin films by varied spin rates." Materials Science-Poland 35, no. 3 (October 20, 2017): 626–31. http://dx.doi.org/10.1515/msp-2017-0077.

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AbstractLiMn2O4 thin films prepared by cost-effective spin coating method using optimized coating conditions are reported. Spin rate was varied and spin rate dependent properties were studied. Prepared films were characterized for their structural, morphological and optical properties. X-ray diffraction study of LiMn2O4 thin films confirmed the cubic spinel structure with the preferred orientation along (1 1 1) plane. Optical absorption studies showed band gap energy of 3.02 eV for the grown LiMn2O4 films. FT-IR bands assigned to asymmetric stretching modes of MnO6 group were located around 623 cm-1 and 514 cm-1 for the LiMn2O4 thin films. The weak band observed at 437 cm-1 was attributed to the LiO4 tetrahedra. The films showed high conductivity value 0.79 S/cm indicating the generation of effective network of the film for enhanced charge transport. AFM micrographs of the LiMn2O4 films deposited at 3000 rpm and 3500 rpm showed uniform distribution of fine grains throughout the surface without any dark pits, pinholes and cracks.

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Zhou, Xian Yan, Mi Mi Chen, Chang Wei Su, Yan Xia, Xiang Zhong Huang, Ying Jie Zhang, and Jun Ming Guo. "Effect of Citric Acid on Electrochemical Properties of Spinel LiMn₂O₄ Prepared by Solid-State Combustion Synthesis." Advanced Materials Research 581-582 (October 2012): 353–58. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.353.

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LiMn2O4 cathode materials were successfully prepared by solid-state combustion synthesis with the lithium carbonate and the manganese carbonate as raw materials and the citric acid as fuel. The effect of citric acid on composition, microstructure and electrochemical properties of LiMn2O4 cathode materials was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV) and galvanostatic charge-discharge test. The results indicated that a pure phase of LiMn2O4 was prepared at the product with 5 wt% citric acid. However, an impure phase of Mn3O4 was found at other products. The crystal size distribution was more uniform at the higher content of citric acid. The products with 5 wt% and 10 wt% citric acid, the cubic structure morphologies of which were more prominent, and the capacities of which were higher than that of bare LiMn2O4 product. Their initial discharge speciﬁc capacities were 119.6 mAh•g-1 and 114.0 mAh•g-1, and their capacity retention ratios after 40 cycles were 85.0% and 87.7%, respectively.

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Sim, San, Injun Hwang, Woosun Choi, and Yongseon Kim. "Synthesis and Surface Coating of LiMn2O4 Nanorods for the Cathode of the Lithium-Ion Battery." Journal of Nanoscience and Nanotechnology 21, no. 10 (October 1, 2021): 5289–95. http://dx.doi.org/10.1166/jnn.2021.19364.

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MnO2 nanorods are prepared using a hydrothermal method, and used as precursors for the synthesis of LiMn2O4 nanorod-based active material for the cathode of lithium-ion batteries. The effects of additives, pressure, reactant concentration in the solution, and reaction time during the hydrothermal synthesis on the morphology of MnO2 are examined. For the synthesis of the LiMn2O4 nanorods, two synthetic methods, hydrothermal processing of the MnO2 precursor in a Li-containing solution, and the solid-state reaction of the precursor with LiOH·H2O powder are tested. The morphological and electrochemical properties of the resulting materials are then analyzed. The rate and cycle performances of the LiMn2O4 nanorods are considerably improved by a composite coating of Li-ion-conductive Li2O–2B2O3 and electrically conductive carbon. Because the conductive properties of these coating materials can be obtained with low crystallinity of them, superior coating performance is attainable with relatively low-temperature of after heating, which is advantageous in preserving the morphology of LiMn2O4 nanorods.

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Xu, Wangqiong, Hongkai Li, Yonghui Zheng, Weibin Lei, Zhenguo Wang, Yan Cheng, Ruijuan Qi, et al. "Atomic Insights into Ti Doping on the Stability Enhancement of Truncated Octahedron LiMn2O4 Nanoparticles." Nanomaterials 11, no. 2 (February 17, 2021): 508. http://dx.doi.org/10.3390/nano11020508.

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Ti-doped truncated octahedron LiTixMn2-xO4 nanocomposites were synthesized through a facile hydrothermal treatment and calcination process. By using spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM), the effects of Ti-doping on the structure evolution and stability enhancement of LiMn2O4 are revealed. It is found that truncated octahedrons are easily formed in Ti doping LiMn2O4 material. Structural characterizations reveal that most of the Ti4+ ions are composed into the spinel to form a more stable spinel LiTixMn2−xO4 phase framework in bulk. However, a portion of Ti4+ ions occupy 8a sites around the {001} plane surface to form a new TiMn2O4-like structure. The combination of LiTixMn2−xO4 frameworks in bulk and the TiMn2O4-like structure at the surface may enhance the stability of the spinel LiMn2O4. Our findings demonstrate the critical role of Ti doping in the surface chemical and structural evolution of LiMn2O4 and may guide the design principle for viable electrode materials.

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Liu, Gui Yang, De Wei Guo, Jun Ming Guo, Li Li Zhang, and Ke Xin Chen. "Solution Combustion Synthesis of LiMn₂O₄ with Different Starting Reactant Compositions." Key Engineering Materials 368-372 (February 2008): 293–95. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.293.

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Spinel LiMn2O4 powders were prepared by solution combustion synthesis using nitrate and acetate salts as raw materials and urea as fuel. The phase composition of as-synthesized powders was identified by XRD and the microscopic structure was examined by SEM. Single-phase spinel LiMn2O4 was prepared when acetate salts were used, and the incorporation of nitrate salts resulted in the formation of Mn2O3. The products consisted of slight agglomerations of fine particles with the size of 50-200nm. It was found that the addition of nitrate salts increased the reaction rate and the yield of LiMn2O4 was depressed when more nitrate salts were used as a reactant.

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Pu, Wei Hua, Xiang Ming He, Guo Yun Zhang, Chang Yin Jiang, Chun Rong Wan, and Shi Chao Zhang. "Preparation of Spherical Spinel LiMn₂O₄ Cathode Material for Lithium Ion Batteries." Key Engineering Materials 336-338 (April 2007): 477–80. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.477.

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A novel process was proposed for preparing spinel LiMn2O4 with spherical particles from cheap materials of MnSO4, NaOH, NH3•H2O and LiOH. Its successful preparation started with a carefully controlled crystallization of Mn3O4, leading to the spherical shape of its particles and a high tap density. The mixture of Mn3O4 and LiOH was sintered to produce LiMn2O4 with spherical particle size retention. The spherical particles of spinel LiMn2O4 were of excellent fluidity and dispersivity, and had tap density as high as 2.14 g cm-3 and the initial discharge capacity reaching 128 mAh g-1. Its 15th cycle capacity kept to be 125 mAh g-1.

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Wang, Ya Zhou, Xuan Shao, Ming Xie, Si Xu Deng, Hao Wang, Jing Bing Liu, and Hui Yan. "Porous LiMn₂O₄ Spheres Synthesized by Topochemical Route Using the Porous Mn₂O₃ as Precursor." Applied Mechanics and Materials 291-294 (February 2013): 708–11. http://dx.doi.org/10.4028/www.scientific.net/amm.291-294.708.

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A facile topochemical route has been developed to synthesize porous LiMn2O4 spheres by using molten LiOH and porous Mn2O3 spheres as a precursor. The formation of porous LiMn2O4 spheres was inherited from porous Mn2O3 spheres which were obtained from the thermal decomposition of the MnCO3 precursors and the presence of pores was confirmed by transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM). When applied as cathode materials for rechargeable lithium-ion batteries, it shows good capacity retention after cycling. Taking the excellent electrochemical performance and facile synthesis into consideration, the presented porous LiMn2O4 spheres could be a competitive candidate cathode material for high-performance lithium-ion batteries.

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Walanda, Daud K. "KINETIC TRANSFORMATION OF SPINEL TYPE LiMnLiMn₂O₄ INTO TUNNEL TYPE MnO₂." Indonesian Journal of Chemistry 7, no. 2 (June 20, 2010): 117–20. http://dx.doi.org/10.22146/ijc.21685.

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Lithiated phase LiMn2O4 is a potential cathode material for high-energy batteries because it can be used in conjunction with suitable carbon anode materials to produce so-called lithium ion cells. The kinetic transformation of LiMn2O4 into manganese dioxide (MnO2) in sulphuric acid has been studied. It is assumed that the conversion of LiMn2O4 into R-MnO2 is a first order autocatalytic reaction. The transformation actually proceeds through the spinel l-MnO2 as an intermediate species which is then converted into gamma phase of manganese dioxide. In this reaction LiMn2O4 whose structure spinel type, which is packing between tetrahedral coordination and octahedral coordination, is converted to form octahedral tunnel structure of manganese dioxide, which is probably regarded as a reconstructive octahedral-coordination transformation. Therefore, it is a desire to investigate the transformation of manganese oxides in solid state chemistry by analysing XRD powder patterns. Due to the reactions involving solids, concentrations of reactant and product are approached with the expression of peak areas. Keywords: high-energy battery, lithium ion cells, kinetic transformation

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Liu, Gui Yang, Jun Ming Guo, and Bao Sen Wang. "Low-Temperature Synthesis of Improved LiMn₂O₄ by a Modified Solution Combustion Synthesis." Advanced Materials Research 143-144 (October 2010): 125–28. http://dx.doi.org/10.4028/www.scientific.net/amr.143-144.125.

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Pure and highly crystalline spinel LiMn2O4 has been successfully prepared by a modified solution combustion synthesis (MSC) method at 400oC for 5h, while strong Mn2O3 impurity is present in the product prepared by conventional solution combustion synthesis (CSC) method on the same conditions. The particle size of LiMn2O4 prepared by MSC method is about 200 nm with a uniformly distribution. Electrochemical tests indicate that the LiMn2O4 prepared by MSC method exhibits a higher capacity, better cycle life and better rate capability than that of prepared by CSC method. It is proved that some disadvantages (such as low purity and bad crystallinity) of CSC method at low temperature can be improved efficiently by MSC method.

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Hirose, Shoji, Takayuki Kodera, and Takashi Ogihara. "Synthesis and Electrochemical Properties of Al Doped Lithium Manganate Powders by Spray Pyrolysis Using Carbonate Aqueous Solution." Key Engineering Materials 485 (July 2011): 111–14. http://dx.doi.org/10.4028/www.scientific.net/kem.485.111.

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Al doped LiMn2O4 powders were prepared by spray pyrolysis using the aqueous solution of manganese carbonate. The aqueous solution, in which manganese carbonate was uniformly dispersed by a surfactant, was used as the starting solution. Al2O3 nanopowders, Al(OH)3 and Al(NO3)3·9H2O were used as the doping agent of Al. A scanning electron microscope photograph showed that Al doped LiMn2O4 powders had spherical morphology with broad particle size distribution. X-ray diffraction revealed that crystal phase of all samples were good agreement with spinel phase. The rechargeable capacity of Al doped LiMn2O4 cathode was about 110 mAh/g at 1 C regardless of doping agent. 75% of initial discharge capacity was maintained after 100 cycles

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El-Metwaly, Fouad, Morsi Abou-Sekkina, Fawaz Saad та Abdalla Khedr. "Synthesis, effect of γ-ray and electrical conductivity of uranium doped nano LiMn2O4 spinels for applications as positive electrodes in Li-ion rechargeable batteries". Materials Science-Poland 32, № 4 (1 грудня 2014): 571–77. http://dx.doi.org/10.2478/s13536-014-0236-7.

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AbstractLiMn2O4 is an attractive candidate cathode material for Li-ion rechargeable batteries, but it suffers from severe capacity fading, especially at higher temperature (55 °C) during charging/discharging processes. Recently, many attempts have been made to synthesize modified LiMn2O4. In this work, a new study on the synthesis of pure and U4+-doped nano lithium manganese oxide [LiMn2−x UxO4, (x = 0:00, 0.01, 0.03)] via solid-state method was introduced. The synthesized LiMn1:97U0:03O4 was irradiated by γ-radiation (10 and 30 kGy). The green samples and the resulting spinel products were characterized using thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared (IR), and scanning electron microscopy (SEM) measurements. XRD and SEM studies revealed nano-sized particles in all prepared samples. Direct-current (DC) electrical conductivity measurements indicated that these samples are semiconductors and the activation energies decrease with increasing rare-earth U4+ content and γ-irradiation. ΔEa equals to 0.304 eV for LiMn1:99U0:01O4, ΔEa is 0.282 eV for LiMn1:97U0:03O4 and decreases to ΔEa = 0:262 eV for γ-irradiated LiMn1:97U0:03O4 nano spinel. The data obtained for the investigated samples increase their attractiveness in modern electronic technology.

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Liu, Gui Yang, Jun Ming Guo, Bao Sen Wang, and Ying He. "Effect of Further Calcination on the Phase Structure of LiMn₂O₄ Prepared by a Solution Combustion Synthesis." Applied Mechanics and Materials 66-68 (July 2011): 768–71. http://dx.doi.org/10.4028/www.scientific.net/amm.66-68.768.

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In this paper, LiMn2O4 materials were prepared by a solution combustion synthesis method using acetate salts as raw materials and acetic acid as fuel. The effect of further calcination at 500°C and 600°C on the phase structure and composition were investigated. The composition and phase structure are determined by X-ray diffraction (XRD). XRD results indicated that the main phase of the products was LiMn2O4,and there was a trace amount Mn2O3 impurity in the products prepared at 500°C and 600°C. The impurity Mn2O3 in the products prepared at 500°C is increased with increasing calcination time, but the Mn2O3 in the products prepared at 600°C is decreased. The grain sizes of the products prepared at 500°C and 600°C are increased with increasing calcination time, and the grain sizes of the products prepared at 600°C are larger than these of the products prepared at 500°C. The lattice parameters of the products prepared at 500°C and 600°C are smaller than that of LiMn2O4 with perfect crystal, and the lattice parameters of the products are more close to that of LiMn2O4 with perfect crystal.

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Yubuta, Kunio, Yusuke Mizuno, Nobuyuki Zettsu, Shigeki Komine, Kenichiro Kami, Hajime Wagata, Shuji Oishi, and Katsuya Teshima. "TEM observation for low-temperature grown spinel-type LiMn2O4crystals." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C749. http://dx.doi.org/10.1107/s205327331409250x.

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Present spinel-type lithium manganese oxides have attracted much attention as positive-electrode active materials for lithium-ion rechargeable batteries, which are the most sought-after power source for various electric applications, because of their low cost, non-toxicity, and high abundance of source materials compared to the conventionally used LiCoO2 crystals. Spinel-type LiMn2O4 crystals were grown at low-temperature by using a LiCl-KCl flux. The chemical compositions, sizes, and shapes of the LiMn2O4 crystals could be tuned by simply changing the growth conditions. Among the various products, the crystals grown at a low temperature of 873 K showed a small average size of 200 nm. Electron diffraction patterns and TEM images reveal the truncated octahedral shape of the crystals. The flux growth driven by rapid cooling resulted in truncated octahedral LiMn2O4 crystals surrounded by both dominating {111} and minor {100} faces with {311} and {220} edges. Lattice images indicate that crystals grown at a lower temperature have the excellent crystallinity. The small LiMn2O4 crystals grown at 873 K showed better rate properties than the large crystals grown at 1173 K, when used as a positive active material in lithium-ion rechargeable batteries.

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Horata, N., T. Hashizume, and A. Saiki. "Synthesis Of Fe Doped LiMn2O4 Cathode Materials For Li Battery By Solid State Reaction." Archives of Metallurgy and Materials 60, no. 2 (June 1, 2015): 949–51. http://dx.doi.org/10.1515/amm-2015-0236.

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Abstract LiFe0.1Mn1.9O4 is expected as a cathode material for the rechargeable lithium-ion batteries. LiMn2O4 has been received attention because this has advantages such as low cost and low toxicity compared with other cathode materials of LiCoO2 and LiNiO2. However, LiMn2O4 has some problems such as small capacity and no long life. LiMn2O4 is phase transformation at around human life temperature. One of the methods to overcome this problem is to stabilize the spinel structure by substituting Mn site ion in LiMn2O4 with transition metals (Al, Mg, Ti, Ni, Fe, etc.). LiFe0.1Mn1.9O4 spinel was synthesized from Li2CO3, Fe2O3 and MnO2 powder. The purpose of this study is to report the optimal condition of Fe doped LiFe0.1Mn1.9O4. Li2CO3, Fe2O3, and MnO2 mixture powder was heated up to 1173 K by TG-DTA. Li2CO3 was thermal decomposed, and CO2 gas evolved, and formed Li2O at about 800 K. LiFe0.1Mn1.9O4 was synthesized from a consecutive reaction Li2O, Fe2O3 and MnO2 at 723 ~ 1023 K. Active energy is calculated to 178 kJmol−1 at 723 ~ 1023 K. The X-ray powder diffraction pattern of the LiFe0.1Mn1.9O4 heated mixture powder at 1023 K for 32 h in air flow was observed.

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Dong, Tao, Suojiang Zhang, Liang Zhang, Shimou Chen, and Xingmei Lu. "Improving Cycling Performance of LiMn2O4 Battery by Adding an Ester-Functionalized Ionic Liquid to Electrolyte." Australian Journal of Chemistry 68, no. 12 (2015): 1911. http://dx.doi.org/10.1071/ch15154.

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Addressing capacity fading during electrochemical cycling is one of the most challenging issues of lithium-ion batteries based on LiMn2O4. Accordingly, in this work, an ester-functionalized ionic liquid, N-methylpyrrolidinium-N-acetate bis(trifluoromethylsulfonyl) imide ([MMEPyr][TFSI]), was designed as an additive to the electrolyte employed for Li/LiMn2O4 batteries to improve their electrochemical performance. A systematic comparative study was carried out using the LiTFSI-based electrolyte with and without [MMEPyr][TFSI] additive. After 100 cycles, the Li/LiMn2O4 half-cells retained 94 % of their initial discharge capacity in the electrolyte containing 10 wt-% [MMEPyr][TFSI]. However, the cycling capacity of the half-cells in the electrolyte without [MMEPyr][TFSI] decreased considerably to ~21 mAh g–1 within the first 10 cycles. One of the main reasons for the decrease is the stabilization of the Al current collector by the [MMEPyr][TFSI] additive, as demonstrated by scanning electron microscopy, cyclic voltammetry, and Fourier transform infrared spectroscopy. Moreover, the Li/LiMn2O4 cells in the electrolyte containing [MMEPyr][TFSI] displayed high-rate performance, whereby ~90 % of the cell initial discharge capacity was retained at 2.5C.

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Liu, Yen Chun, Ming Cheng Liu, Robert Lian Huey Liu, and Mao Chieh Chi. "Effect of the Doping Ni and Overdosing Lithium for Synthesis LiMn₂O₄ Cathode Material by the Solid State Reaction Method." Applied Mechanics and Materials 457-458 (October 2013): 93–97. http://dx.doi.org/10.4028/www.scientific.net/amm.457-458.93.

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The study with Li2CO3 and Mn3O4 through the solid state reaction makes cathode material for lithium battery spinel - LiMn2O4. According to past literature, under the solid-state reaction. The experiment carries out sintering at temperature of 850°C.. Cathode materials under these sintering temperatures are made to fabricate battery. For Ni doped LiMn2O4, the capacitance decreasing speed is slow and stable; after 15 times charging-discharging cycles, the attrition rates were 3.05 % or less. The result of experiment demonstrates that the best sintering temperature is at 850°C. Under the condition of 850°C, various contents for extra amount of lithium (1.02 mole-1.1 mole) are fabricated and range of working voltage is released. It is found a further increase of initial capacity to 140.51 mAh/g. LiMn2O4 further extends circulation and usage.

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Li, Bin, Ming Wu Xiang, Zhi Fang Zhang, Ji Jun Huang, Hong Li Bai, Gui Yang Liu, and Jun Ming Guo. "Effect of Temperature on LiMn₂O₄ Prepared by Molten-Salt Combustion Synthesis." Advanced Materials Research 941-944 (June 2014): 593–97. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.593.

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Spinel LiMn2O4 was prepared by a molten-salt combustion synthesis using eutectic acetate salts as starting materials without any additional molten-salt at 400°C, 500°C, 600°C and 700°C for 3h. The experimental results show that the main phase of the produts is spinel LiMn2O4, and the impurities are Mn2O3 or Mn3O4. It has been found that elevated temperature was easy to generate Mn3O4, and low temperature was easy to generate Mn2O3. The product prepared at 600 °C is single phase LiMn2O4 and has good crystallinity. With increasing combustion reaction temperature, the particle sizes of the products were decreased. The product prepared at 600 °C has the highest initial specific capacity of 116.5 mAh•g-1 at 0.2C, the capacity retention was only 77.2% after 50 cycles.

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Kang, Jungwon, Jinju Song, Sungjin Kim, Jihyeon Gim, Jeonggeun Jo, Vinod Mathew, Junhee Han, and Jaekook Kim. "A high voltage LiMnPO4–LiMn2O4 nanocomposite cathode synthesized by a one-pot pyro synthesis for Li-ion batteries." RSC Advances 3, no. 48 (2013): 25640. http://dx.doi.org/10.1039/c3ra44415e.

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Meng, Qi, Jianguo Duan, Yingjie Zhang, and Peng Dong. "Novel efficient and environmentally friendly recovering of high performance nano-LiMnPO4/C cathode powders from spent LiMn2O4 batteries." Journal of Industrial and Engineering Chemistry 80 (December 2019): 633–39. http://dx.doi.org/10.1016/j.jiec.2019.08.051.

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Xiang, Ming Wu, Xian Yan Zhou, Zhi Fang Zhang, Mi Mi Chen, Hong Li Bai, and Jun Ming Guo. "LiMn₂O₄ Prepared by Liquid Phase Flameless Combustion with F-Doped for Lithium-Ion Battery Cathode Materials." Advanced Materials Research 652-654 (January 2013): 825–30. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.825.

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LiMn2O4-yFywere synthesized by a novel method named liquid phase flameless combustion reaction with LiNO3, MnAc2.4H2O and LiF as raw materials calcined at 600 °C for 3 h with HNO3as aided oxidant. All samples were investigated by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and electrochemical performance. The results show that: all samples have main phase of LiMn2O4with impurity of Mn3O4and the vibrational bands of Mn-O are a little red shift by doping F, which indicated that the F- enter the host structure of LiMn2O4successfully. The electrochemical performance show that the initial discharge capacities of F-doped samples are lower than pristine LiMn2O4, which is 117.7 mAh•g-1. However, the capacity retention of LiMn2O3.96F0.04and LiMn2O3.90F0.10are 73.6% and 74.5%, respectively, which are higher than pristine LiMn2O4, which is only 69.0% after 40 cycles.

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