High conductivity polymer electrolyte with comb-like structure via a solvent-free UV-cured method for large-area ambient all-solid-sate lithium batteries

A novel solid polymer electrolyte with comb-like structure is prepared via a solvent-free UV-cured method.The relationship between conductivity and molecular weight is investigated and revealed.The optimal electrolyte presents a considerably high conductivity of 1.44·10^(-4)S·cm^(-1)at 30℃.Meanwhile,it shows excellent compatibility with metallic lithium and wide electrochemical window(>5 V).To investigate the safety and cycling performance,the coin cell and soft package battery are assembled respectively.The LiFePO_(4)/Li coin cells exhibit initial discharge specific capacities of 163.2,147.7,137.3 and 108.7 mA·h·g^(-1)at 0.1,0.2,0.5 and 1C under 60℃,respectively.Notably,when the coin cells work at 30℃,the initial discharge specific capacities at 0.05,0.1,0.2 and 0.5C are 140.5,133.5,107.7 and 55.6 mA·h·g^(-1).Significantly,a 3.5 cm×7 cm solid-state soft pack battery is fabricated and cycling at 30℃.The first discharge capacity reaches to 137.5 mA·h·g^(-1)and the capacity retention is as high as 84.4%after 100 cycles at 0.2C and remain 95.5%after 100 cycles at 0.5C,respectively.These results shows a promising solid polymer electrolyte for solid-state batteries with good cycling and safety performance.