An integrated cathode and solid electrolyte via in situ polymerization with significantly reduced interface resistance

Abstract

Reducing the interfacial resistance between solid electrolytes and electrodes is critical for developing high-energy density solid-state batteries. In the present study, a simple strategy of designing an integrated cathode and solid electrolyte (ICSE) to avoid a contact interface is proposed and successfully fulfilled with the help of UV curving. Firstly, a porous polymer film (PVDF-HFP/PVDF) was formed on the surface of the porous LiFePO₄ electrode via PVP dissolution. Secondly, curable monomers, including PEGDA/PETMP/TFEMA, were filled into the porous membrane via infiltration and concentration. Lastly, the ICSE was obtained via curing with ultraviolet light. The as-prepared LiFePO₄//ICSE//Li solid battery displays excellent electrochemical performance with a high reversible capacity of 153 mA h g⁻¹ and a capacity of over 140 mA h g⁻¹ was retained after 150 cycles at 0.1C and 25 °C. This ICSE strategy may effectively contribute to the practical application of all-solid-state batteries.