Synthesis and electrochemical performance of rod-like spinel LiMn sub(2)O sub(4) coated by Li-Al-Si-O solid electrolyte

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2013-11, Vol.1 (46), p.14729-14735
• Main Authors: Hu, Dao-Heng, Zhao, Shi-Xi, Deng, Yu-Feng, Nan, Ce-Wen
• Format: Article
• Language: English
• Subjects: Cathodes; Coating; Electrochemical analysis; Rods; Scanning electron microscopy; Solid electrolytes; Spinel; Sustainability
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c3ta13499g

Li sub(1.05)Co sub(0.1)Mn sub(1.9)O sub(3.95)F sub(0.05) rods with a spinel structure were synthesized by a topochemical conversion route, and a Li-Al-Si-O (LASO) glassy solid electrolyte was used to modify the surface of the cathode material. The structure and electrochemical properties were investigated using X-ray diffraction, scanning electron microscope, transmission electron microscope and electrochemical tests. XRD, SEM and TEM observations show that Li sub(1.05)Co sub(0.1)Mn sub(1.9)O sub(3.95)F sub(0.05) materials have a single crystal of cubic spinel structure and exhibit a rod-like morphology with a diameter of 400-500 nm. The electrochemical results indicate that LASO-coated Li sub(1.05)Co sub(0.1)Mn sub(1.9)O sub(3.95)F sub(0.05) rods exhibit an excellent rate capability and cycle stability at elevated temperatures and high rates. The initial discharge capacity of the LCMOF-rod-LASO sample is 93.9 mA h g super(-1) under 10 C at 55 degree C, and the capacity retention ratio is higher than 96% after 200 cycles. Even under 15 C at 55 degree C, the cathode material shows a high capacity of 87 mA h g super(-1). The cyclic voltammograms and impedance spectra results reveal that the LASO coating enhances the kinetics of the lithium-ion diffusion through the surface layer and the charge transfer reaction, improving the electrochemical activity of the cathode. Thus, the LASO-coated Li sub(1.05)Co sub(0.1)Mn sub(1.9)O sub(3.95)F sub(0.05) rods have shown potential for high power applications in lithium ion batteries.