The Influence of Particle Characteristic of Manganese Dioxide on Performance of Spinel Lithium Manganese Oxide

2016 ◽  
Vol 852 ◽  
pp. 816-821
Author(s):  
Wei Li ◽  
Wen Huai Tian ◽  
Lu Qi

Several kinds of chemical manganese dioxide with different particle characteristic were prepared by redox reaction in liquid phase. Then, spinel lithium manganese oxide was synthesized by liquid impregnation. The result implied that the influence of particle characteristic on test result is important. The spinel lithium manganese oxide prepared by spherical MnO2 has better cycle performance than the spinel lithium manganese oxide prepared by MnO2 with irregular shape .The spinel lithium manganese oxide with little particle size has high initial specific capacity. The spinel lithium manganese oxide prepared by MnO2 with anemone shape has high specific capacity and stable cycle performance.

2009 ◽  
Vol 12 (10) ◽  
pp. 64-71
Author(s):  
Binh Thi Xuan Lam ◽  
Phung My Loan Le ◽  
Thoa Thi Phuong Nguyen

Lithium manganese oxide (LiMn2O4) spinel compounds were synthesized by melting impregnation method using manganese dioxide (MnO2) and lithium nitrate (LiNO3). Four sources of MnO2 raw materials were used: a commercial electrochemical manganese dioxide (EMD) supplied by Pin Con O factory; EMD thermal pretreated (EMDt); and MnO2 synthesized chemically (CMD) by oxidation of MnSO4 solution with K2S2O, and EMD synthesized in our laboratory. The effect of the MnO2 materials on the microstructure and electrochemical properties of LiMn2O4 is investigated by X-ray diffraction, scanning electron microscopy, and electrochemical measurements. The charge-discharge cycling behavior in Swagelok model of lithium-ion cells, using synthesized LiMn2O4 as cathode, lithium metal as anode and LiPF6 as electrolyte with Whatman glass separator, showed that the spinels from thermal treated EMDt and CMD gave higher (3100 mAh/g) and more stable values of specific capacity than the spinels from non-treated EMD.


2003 ◽  
Vol 18 (3) ◽  
pp. 552-559 ◽  
Author(s):  
Chung-Hsin Lu ◽  
Yueh Lin

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.


1998 ◽  
Vol 66 (12) ◽  
pp. 1198-1201 ◽  
Author(s):  
Masaki YOSHIO ◽  
Hideyuki NOGUCHI ◽  
Yanko TODOROV ◽  
Yasufumi HIDESHIMA

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