Uniform Lithium Nucleation Guided by Atomically Dispersed Lithiophilic CoNx Sites for Safe Lithium Metal Batteries

The mossy lithium dendrite growth during repeated lithium plating/stripping induces low Coulombic efficiency, poor lifespan, and safety concerns of working lithium metal batteries. Herein, atomically dispersed CoNx-doped graphene is exploited as a host to accommodate dendrite-free lithium deposits. The coordination between Co and N in the conductive matrix can effectively regulate the local electronic structure, and thereby enhance the adsorption of lithium ions and promote the following nucleation process. Meanwhile, the doped N facilitates high dispersion of Co atoms into graphene through the Co-N coordination bond. The strong lithiophilicity provided by N coordinated with Co promises a uniform lithium nucleation behavior, further contributing to the smooth lithium deposition morphology. These characteristics afford a superhigh Coulombic efficiency of 99.2% at 2.0 mA cm(-2) (approximate to 400 cycles) and 5.0 mA cm(-2) (350 cycles), and 98.2% at 10.0 mA cm(-2) (200 cycles) with a capacity of 2.0 mAh cm(-2). LiFePO4|CoNC-Li full cells deliver a long lifespan of 340 cycles at 1.0 C (240 cycles for routine cells). This offers fresh insights into effectively regulating the lithiophilic chemistry of lithium metal host toward uniform nucleation and growth of lithium deposits in working high-energy-density batteries.