PEO kaolinite intercalation interface accelerates lithium-ion transfer for all-solid-state lithium metal batteries

The improvement of ionic conductivity and Li dendrite inhibition capability of poly(ethylene oxide)(PEO)-based solid polymer electrolytes(SPEs) is urgent for the development of all-solid-state lithium metal batteries (ASSLMBs). Here, intercalated composite consisted with PEO polymer chains inserted into the clay gallery of the formamide intercalated kaolinite (KM) is formed. Due to this alternating organic-inorganic layered structure, the crystallinity of PEO decreases to 26.2% and the ion conductivity of SPE with 3% KM of PEO mass added(PEO+KM-3) increased to 1.43 x 10(-3) S cm(-1) at 60 degree celsius. Besides, bis (trifluoromethane) sulfonimide lithium salt (LiTFSI) interacts with formamide to form a complex, making the local solvated Li+ transports close to a quasi-solid model. PEO+KM-3 SPE exhibits a good inhibition effect on lithium dendrites due to the formation of organic silicon at lithium anode side, and Li/ PEO+KM-3/Li cell works steadily for more than 1600 h at 60 degree celsius with 0.1 mA cm(-2). The assembled Li//LiFePO4 cell provides a capacity of 118 mAh g(-1) after 500 cycles at 0.5 C at 60 degree celsius.