A semi-interpenetrating network polymer electrolyte membrane prepared from non-self-polymerized precursors for ambient temperature all-solid-state lithium-ion batteries

Solid polymer electrolytes (SPEs) are currently attracting widespread interest for lithium battery applications due to high safety, low volatility, and the ability to suppress Li dendrites. Herein, a novel all-solid-state polymer electrolyte with semi-interpenetrating network (semi-IPN) structure has been prepared. The semi-IPN SPE is fabricated by thiol-tosylate polycondensation of pentaerythritol terakis (3-mercaptopropionate) (PETMP) with non-self-polymerized precursors, ditosylate poly (ethylene glycol) (DTsPEG) and p -toluenesulfonyl poly (ethylene glycol) methyl ether (TsPEGME), and then blended with a high molecular weight polyethylene oxide (PEO, M w  ​= ​300 ​kg ​mol −1 ). The resulting self-standing membrane achieves an excellent ionic conductivity (1.3 ​× ​10 −4  ​S ​cm −1 ) at ambient temperature, and exhibits an electrochemical stability window up to 4.3 ​V vs. Li/Li + . The LiFePO 4 /semi-IPN-SPE/Li battery exhibits a first discharging capacity of 143.1 ​mA ​h ​g −1  ​at 0.2C and the discharge capacity keeps 134 ​mA ​h ​g −1 after 100 charge and discharge cycles.