Efficient Construction of a C 60 Interlayer for Mechanically Robust, Dendrite-free, and Ultrastable Solid-State Batteries
Interfacial instability between solid electrolytes (SEs) and lithium metal remains a daunting challenge for solid-sate batteries. Here, a conformal C 60 interlayer is efficiently constructed on Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) SEs by physical vapor deposition, and an ideal interfacial contact is achieved via forming an ionically conducting matrix of LixC60 with lithium metal. The obtained Li x C 60 is beneficial to hinder the growth of lithium dendrites at interface and release the local stress during the lithiation and delithiation. As a result, the Li/LAGP-C 60 /Li symmetric cells demonstrate ultra-stable cycling performance for more than 4,500 h at a current density of 0.034 mA cm -2 . The Li/LAGP-C 60 /LiFePO 4 full cells deliver a reversible capacity of 152.4 mAh g -1 at room temperature, and the capacity retention rate is 85% after more than 100 cycles. This work provides a feasible and scalable strategy to improve the SEs/Li interface for high-performance solid-state batteries.