Trimethyl phosphate-enhanced polyvinyl carbonate polymer electrolyte with improved interfacial stability for solid-state lithium battery

摘要

The polyvinyl carbonate(PVC)polymer solid electrolyte can be in-situ generated in the assembled lithium-ion battery(LIBs);however,its rigid characteristic leads to uneven interface contact between electrolyte and electrodes.In this work,trimethyl phosphate(TMP)is introduced into the precursor solution for in-situ generation of flexible PVC solid electrolyte to improve the interfacial contact of elec-trolyte and electrodes together with ionic conductivity.The PVC-TMP electrolyte exhibits good interface compatibility with the lithium metal anode,and the lithium symmetric battery based on PVC-TMP electrolyte shows no obvious polarization within 1000 h cycle.As a consequence,the initial interfacial resistance of battery greatly decreases from 278Ω(LiFePO_(4)(LFP)/PVC/Li)to 93Ω(LFP/PVC-TMP/Li)at 50℃,leading to an improved cycling stability of the LFP/PVC-TMP/Li battery.Such in-situ preparation of solid electrolyte within the battery is demonstrated to be very significant for commercial application.