Investigation on polyethylene supported poly(butyl methacrylate-acrylonitrile-styrene) terpolymer based gel electrolyte reinforced by doping nano-SiO2 for high voltage lithium ion battery

In this paper, we design a novel gel polymer electrolyte (GPE), based on polyethylene (PE) supported poly(butyl methacrylate-acrylonitrile-styrene) (P(BMA-AN-St)) terpolymer reinforced by doping 10 wt.% nano-SiO2, to be possible application in high voltage lithium ion battery. The physical characterization indicates that P(BMA-AN-St)/SiO2/PE membrane has multi-layered and cross-linked network structure with the pore diameter of about 1 μm, leading to the highest electrolyte uptake ability of 257% compared with the value of 118% for PE support. Electrochemical performance exhibits that the corresponding GPE presents highest ionic conductivity of 1.9 × 10−3 S cm−1 at room temperature and the improved oxidative stability from 4.2 V (PE support saturated with liquid electrolyte) to 5.2 V (vs. Li/Li+). Thus, the high voltage cathode LiNi0.5Mn1.5O4 using nano-SiO2 doped GPE presents excellent cyclic stability and rate performance, which retains 93.0% of its initial discharge capacity after 150 cycles at 0.2C rate and keeps 95.0% discharge capacity at 2C rate of that at 0.1C rate, while PE support saturated with liquid electrolyte has 87.9% capacity retention after 150 cycles and with the rate capacity value of 86.8% at the same rate test condition.