A dual-lithiophilic interfacial layer with intensified Lewis basicity and orbital hybridization for high-performance lithium metal batteries

Abstract

Controlling Li nucleation and growth by an interfacial layer is one of the critical challenges to achieving practical lithium metal batteries. In this work, we present a dual-lithiophilic interlayer, which has affinity to both Li+ and Li0 with the concept of intensified Lewis basicity and orbital hybridization. It was achieved by phosphorus-doped carbon nitride (PCN) layers in contact with Li metal electrode. Spectroscopic and electrochemical analyses demonstrated that strong interaction between the Li+ and PCN facilitates the charge transfer process. Driven by the orbital hybridization, under the PCN interfacial layer Li deposits grow with a planar morphology, mitigating electrolyte decomposition. A Li/Li symmetric cell employing the PCN interfacial layer operated for more than 400 cycles at 2 mA cm-2 and 2 mAh cm-2. Furthermore, a Li/NCM811 pouch cell with the PCN interfacial layer stably operated with 70% capacity retention for 330 cycles under practical operating conditions.