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

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.

Automated summary

This study demonstrates the importance of controlling Li nucleation and growth through the use of a phosphorus-doped carbon nitride interfacial layer, which promotes stable operation of lithium metal batteries and effectively reduces electrolyte decomposition.