Preparation And Electrochemical Properties Study Of Plastic Crystal Polymer Electrolyte For Lithium Ion Battery

Lithium-ion batteries commonly use carbonate organic solvent electrolytes,which have problems such as easy leakage,low flash point,poor safety,poor high-temperature performance,and inability to suppress the growth of lithium dendrites,which leads to the promotion and application of lithium-ion batteries.Therefore,the safety issue that needs to be solved becomes the important for the further promotion and application of lithium-ion batteries.This article uses UV curing and in-situ polymerization to prepare all-solid polymer electrolytes to study all-solid polymer electrolytes.Electrochemical performance at room temperature and at high temperature environments by LiFePO₄/polymer electrolyte/Li polymer batteries.In this paper,the solid-state polymer electrolyte supported by porous membranes was prepared by phase-conversion method and prepared by UV-curing method.The ethoxylated trimethylolpropane triacrylate（ETPTA）was used as the polymerization monomer and UV curing was used to prepare the solid polymer electrolyte.The polymer electrolyte can improve the mechanical strength of the polymer electrolyte,has a low requirement for the packing of the battery,reduces the interface resistance of the electrode,and can also make the contact between the electrode and the polymer electrolyte more tight,and can obtain better electrochemical performance.The polymer electrolyte has better thermal stability below 180℃,and the mass loss is relatively small,which is favorable for the polymer electrolyte working under high temperature.The assembled Li FePO₄/UV-cured polyelectrolyte/Li polymer battery exhibited an initial discharge specific capacity of 154.2 mAh/g at room temperature,It has 113.8mAh/g at 10 C,The cell of Li FePO₄/UV-PCCE/Li employing UV-PCCE as electrolyte delivered excellent capacity retention（97.3%）after 150 cycles at 1.0 C and outstanding rate capability（119.7 m Ah/g at 10.0 C）at 55℃.The solid polymer electrolyte prepared by using polyimide as a base to prepare a plastic crystalline polymer electrolyte was prepared by using Cyclic Trimethylopropane Formal Acrylate（CTFA）as a polymerization monomer and an in-situ polymerization method.The electrolyte has 4.64 V working voltage window,good thermal stability.The assembled LiFePO₄/in-situ polymer electrolyte/Li battery has an initial discharge capacity of 153.9 mAh/g at 0.2 C at room temperature.After 100 cycles,the capacity retention rate approaches 93.5%.At 55℃,the initial discharge capacity is about 150mAh/g at 2 C,the capacity retention rate exceeds 96%after 150 cycles,the capacity retention rate approaches 99%after 200 cycles at 55℃ and outstanding rate capability（115.2 mAh/g at 10.0 C）,indicating that the in-situ polymer electrolytes could applied to power battery prospects at high temperature.