In Situ Polymerized Polydioxolane Interlayer Enabled Dendrite-Free Argyrodite-Based Solid-State Batteries

Solid-state batteries (SSBs) involving argyrodite-type sulfide electrolytes are considered as promising candidates for the state-of-art lithium-ion batteries (LIBs) due to their superior safety, energy and power density. However, the incompatibility between the argyrodite-type sulfide and lithium anode has plagued the development of the sulfide-based SSBs. Herein, we introduced a poly-dioxolane-based (PDOL) interlayer at the lithium anode, which is ring-opening polymerized via poly(acrylamide-2-methyl-1-propane-sulfonate) (PAMPS) loaded on the separator. The in-situ polymerized PDOL interlayer could match with the solvent-sensitive lithium argyrodite while enabling a stable and tight lithium interface. The symmetric lithium cell with the PDOL interlayer exhibits over-1200-hour dendrite-free lithium deposition and stripping at 0.5 mA cm‑2, and the critical current density reaches 2.7 mA cm-2. The as-cycled lithium interface is further investigated via the depth-profiling X-ray photoelectron spectroscopy, and solid electrolyte interphase (SEI) is determined to be composed of ether polymer as well as inorganic compounds like LiC, Li2O, LiF, and Li2S. The Li|LiCoO2 SSB with PDOL interlayer presents a high discharge capacity of 120.7 mAh g-1 at 0.1 C and a capacity retention rate of 95.4% after 200 cycles. The rational design of the PDOL interlayer at the lithium anode opens a new alternative for high-performance SSBs.