Electrochemical performance of Li2O-V2O5-SiO2-B2O3 glass as cathode material for lithium ion batteries

摘要

A series of 20Li_(2)O-30V_(2)O_(5)-(50- x) SiO_(2)- x B_(2)O_(3) (mol.%) ( x ?=?10, 20, 30, 40) glasses were prepared by the traditional melt-quenching synthesis. The amorphous nature of the glasses was determined by XRD, DSC and TEM investigations. FTIR measurement revealed the functional group of obtained glasses. And EDS results confirmed the presence and uniform distribution of elements in the glasses. 20Li_(2)O-30V_(2)O_(5)-40SiO_(2)-10B_(2)O_(3) (LVSB10) sample with the highest V~(4+) ratio exhibited the best cycling capacity. In order to further improve cycling stability of LVSB10 sample, ball milling was employed to reduce the particle size. The ball milled LVSB10 sample (LVSB10-b) showed an improved first discharge capacity, cycling stability and rate capacity. EIS measurements showed that ball milling can effectively decrease charge transfer impedance and facilitate Li~(+) ion diffusion. This work provides a new way to explore a new type of cathode materials for lithium ion batteries.