Nitrates�?�melt synthesized LiNi0.8Co0.2O2 and its performance as cathode in Li-ion cells

Bulletin of materials science

A K Shukla¹  K Hemalatha²  M Sathiya²  K Ramesha²  A S Prakash² 

[1] Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India$$Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, IndiaSolid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India$$;CSIR â€�?? Central Electrochemical Research Institute â€�?? Chennai Unit, CSIR â€�?? Madras Complex, Chennai 600 113, India$$CSIR â€�?? Central Electrochemical Research Institute â€�?? Chennai Unit, CSIR â€�?? Madras Complex, Chennai 600 113, IndiaCSIR â€�?? Central Electrochemical Research Institute â€�?? Chennai Unit, CSIR â€�?? Madras Complex, Chennai 600 113, India$$

关键词: Lithium batteries;    intercalation compounds;    electrochemical characterization;    diffusion.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Layered LiNi_0.8Co_0.2O₂ crystallizing in space group is synthesized by decomposing the constituent metalâ€�?�nitrate precursors. Oxidizing nature of metal nitrates stabilizes nickel in +3 oxidation state, enabling a high degree of cation ordering in the layered LiNi_0.8Co_0.2O₂. The powder sample characterized by XRD Rietveld refinement reveals < 2% Liâ€�?�Ni site exchange in the layers. Scanning electron microscopic studies on the as-synthesized LiNi_0.8Co_0.2O₂ sample reflect well defined particles of cubic morphology with particle size ranging between 200 and 250 nm. Cyclic voltammograms suggest that LiNi_0.8Co_0.2O₂ undergoes phase transformation on first charge with resultant phase being completely reversible in subsequent cycles. The first-charge-cycle phase transition is further supported by impedance spectroscopy that shows substantial reduction in resistance during initial de-intercalation. Galvanostatic chargeâ€�?�discharge cycles reflect a firstdischarge capacity of 184 mAh g^-1 which is stabilized at 170 mAh g^-1 over 50 cycles.

【 授权许可】

Unknown