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

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 electrolyte 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 278 Omega (LiFePO4 (LFP)/PVC/Li) to 93 Omega (LFP/PVC-TMP/Li) at 50 degrees C, 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.