Preparation of polymer solid electrolyte by in-situ polymerization of DOL initiated by SN enhanced ionic liquid-lithium salt binary components
YUAN Xinna
LI Jian
NIE Haiying
Abstract：Solid polymer electrolytes(SPE)are regarded as the core materials for the next-generation high-energy-density lithium batteries due to their excellent mechanical properties,good interfacial compatibility and high safety.However,their wide application is limited by problems such as low ionic conductivity,poor interfacial compatibility and insufficient electrochemical stability.This study proposes a controllable initiation system based on the two-component ionic liquid-lithium salt,achieving cationic ring-opening polymerization of 1,3-dioxopentane(DOL)monomers,and further introducing butanitrile(SN)to prepare high-performance polymerization of 1,3-dioxopentane(PDOL)-based electrolytes.The research found that SN effectively inhibited the crystallization of the matrix through the hydrogen bond interaction between the cyanide group and the PDOL chain,constructed a continuous amorphous ion channel,increased the room-temperature ionic conductivity of the PDOL-SN40 electrolyte to 1.1×10-3 S/cm,and the lithium ion migration number reached 0.83.Meanwhile,the introduction of SN broadens the electrochemical window of the electrolyte and significantly inhibits lithium dendrites and interfacial side reactions by in-situ forming a LiF-rich solid electrolyte interface(SEI)film.Electrochemical tests show that the lithium symmetrical battery assembled with PDOL-SN40 remains stable after 1 600 h,and the lithium metal deposition morphology is uniform.The capacity retention rate of the Li/LFP full battery reached 91.8%after 600 cycles at 0.5 C,and it still maintained a capacity output of 85.3%at a rate of 2 C.This research provides a new idea for the development of solid electrolytes with high ion conductivity,wide voltage window and interface stability,and promotes the practical application process of high-safety lithium metal batteries.
Keywords：solid polymer electrolytein-situ polymerization13-epoxy pentaneadiponitrileionic liquid
Publication Date：2025-08-25
Online Publishing Date：2025-09-22(First online date of this platform, not the publication date of the document)
Pages：9( 253-261 )