An Elastomeric Lithium-Conducting Interlayer for High-Performance LATP-Based Lithium Metal Batteries

In response to the critical challenges of interfacial impedance and volumetric changes in Li (1+x) Al x Ti (2‑x) (PO 4 ) 3 (LATP)-based lithium metal batteries, an elastomeric lithium-conducting interlayer fabricates from fluorinated hydrogenated nitrile butadiene rubber (F-HNBR) matrix is introduced herein. Owing to the vulcanization, vapor-phase fluorination, and plasticization processes, the lithium-conducting interlayer exhibits a high elasticity of 423%, exceptional fatigue resistance (10 000 compression cycles), superior ionic conductivity of 6.3 × 10 −4 S cm −1 , and favorable lithiophilicity, rendering it an ideal buffer layer. By integrating the F-HNBR interlayer, the LATP-based lithium symmetric cells demonstrate an extended cycle life of up to 1600 h at 0.1 mA cm −2 and can also endure deep charge/discharge cycles (0.5 mAh cm −2 ) for the same duration. Furthermore, the corresponding lithium metal full cells achieve 500 cycles at 0.5 C with 98.3% capacity retention and enable a high-mass-loading cathode of 11.1 mg cm −2 to operate at room temperature.