Interfacial stabilization of LATP in lithium-metal batteries by in situ-formed poly(1,3-dioxolane) gel interlayers

Poor interfacial contact and reduction-related degradation hinder direct coupling of LATP with Li metal. Herein, a pDOL/LATP configuration was constructed by the in situ polymerization of a DOL-based precursor containing multiple lithium salts on dense LATP. The pDOL interlayer exhibited a room-temperature ionic conductivity of 2.71 mS cm^-1, while pDOL/LATP showed an apparent Li⁺ transference number of 0.92 and an apparent oxidation onset of 4.26 V versus Li/Li⁺. Li|pDOL/LATP|Li cells exhibited limited impedance evolution over 96 h of storage and sustained 1200 h of cycling at 0.1 mA cm^-2 and 0.1 mAh cm^-2 with low polarization. Post-cycling Ti 2p XPS spectra showed no detectable Ti³⁺-related contribution for the LATP surface recovered from the pDOL/LATP cell, whereas a distinct Ti³⁺-related contribution was observed for the surface recovered from the bare LATP cell. A Li|pDOL/LATP|LFP full cell delivered 166.2 mAh g^-1 at 0.2 C and retained 142.2 mAh g^-1 after 200 cycles at 0.5 C, corresponding to a 90.4% capacity retention.