Metal organic frameworks enabled rational design of multifunctional PEO-based solid polymer electrolytes

Abstract

Abstract Electrochemical performance, mechanical properties as well as fire safety are crucial factors to evaluate solid polymer electrolytes (SPEs). In this article, we purposely choose metal-organic frameworks (HKUST-1 MOFs) as the multifunctional additive to modify the PEO-based SPEs. The PEO-LiTFSI-10HKUST-1 MOFs electrolyte (PL10HM) has shown enhanced ionic conductivity, which reaches 2.4\xa0×\xa010−3\xa0S\xa0cm−1 at 80\xa0°C. With the HKUST-1 MOFs, the electrochemical stability window and lithium-ion transfer number were largely enhanced as compared to the PEO-LiTFSI electrolyte (PL). The crystal structure, morphology, thermal stability, micro and macro mechanical properties were characterized systematically. The reduction in peak heat release rate (pHRR) of 42% was realized, which means the PL10HM possesses higher fire safety. The as-fabricated Li/PL10HM/LiFePO4 battery exhibited a simultaneous good rate capability up to 1C and highly stable cyclability for over 100 cycles. These results demonstrate the unique characteristics of such a novel electrolyte membrane, potentially enabling the high performance, safe use in the practical solid-state batteries.