A facile strategy to reconcile 3D anodes and ceramic electrolytes for stable solid-state Li metal batteries

Lithium metal batteries (LMBs) are regarded as the promising candidate for next-generation energy storage devices. Three-dimensional (3D) current collector is one of the effective anode materials for suppressing lithium (Li) dendrite and accommodating the variation of Li volume during the cycling. However, since the protruding 3D skeleton will also pierce the separator and cause catastrophic battery failure, the safety risk of short circuit still exists. The use of ceramic solid-state electrolyte (SSE) with high mechanical stability on the 3D anode can eliminate the danger of short circuit caused by Li dendrites or 3D skeleton. Nevertheless, in solid-state batteries, 3D anodes with highly electroactive areas suffer from considerable interface reactions and high interface impedance. Herein, we demonstrate a facile in-situ polymerized sealing (IPS) strategy to reconcile the 3D anode with ceramic SSE. The optimized battery configuration consists of 3D anode, in-situ polymerized interlayer and NASICON-type ceramic electrolyte of Li1.3Ti1.7Al0.3(PO4)3 (LATP). The in-situ polymerized interlayer not only significantly reduces the interfacial resistance between the 3D anode and LATP, but also encapsulates liquid electrolyte within the electrode for indispensable interface reactions and rapid Li+ transport. Resultingly, the symmetric cell of 3D Li | LATP | 3D Li delivered a long cycle life of 500 ​h. Moreover, this unique configuration can be paired with a LiNi0.6Co0.2Mn0.2O2 cathode and operate at room temperature, which exhibits excellent performances. This work provides a practical strategy for building safe and durable high-energy solid-state LMBs suitable for next-generation energy storage devices.