Foldable nano-Li2MnO3 integrated composite polymer solid electrolyte for all-solid-state Li metal batteries with stable interface.

ABSTRACT

All-solid-state lithium-ion batteries (ASSLBs) are considered as the most promising next-generation energy storage devices. In this work, a low-cost foldable nano-Li2MnO3 integrated Poly (ethylene oxide) (PEO) based composite polymer solid electrolyte (CPSE) is prepared by simply solid-phase method. Density functional theory calculations indicate that the LMO could provide faster ion transfer channels for the migration of lithium ions between PEO chains and segments. As such, the CPSE obtained has a high ionic conductivity of 5.1 × 10-4 S cm-1 at 60 °C with a high lithium ions transference number of 0.5. The CPSE remains stable even at high temperature with no heat escaping. This could improve the safety performance of the batteries. As a result, the lithium metal battery assembled with CPSE works stably after over 200 cycles at a high rate of 0.5C, and its specific capacity is as high as 125 mAh g-1. Also, it is confirmed that this CPSE adapts to three cathode materials. The Li metal pouch battery assembled with the CPSE is foldable and has excellent mechanical properties. All these results indicate that the CPSE obtained has excellent electrochemical and outstanding safety performances, which can make it have broad commercial applications in ASSLBs.