Self-supporting lithiophilic N-doped carbon rod array for dendrite-free lithium metal anode

Abstract

Carbon materials as host matrix of lithium (Li) anode attract more and more attention in order to inhibit uncontrollable dendritic growth of Li. Powdery carbon materials are usually synthesized and loaded on current collector by binder. The pore structure and active site of powdery materials will be easily destroyed during cycling. Herein, a self-supporting carbon film consisting of nitrogen (N)-doped carbon rod array (NCRA) with high N content and large surface area skeleton is developed as Li host matrix to regulate Li metal nucleation and suppress dendrites growth. The NCRA matrix exhibits low lithium loss mass and good long-term cycling stability during Li plating/stripping. The loss mass of Li in each cycle on NCRA is less than 0.01 mg cm−2 at 1.0 mA cm−2 and the value is much smaller than that (0.063 mg cm−2) on Cu foil. The Li|NCRA@Li symmetric cell has ultralong lifespan beyond 620 h and small voltage hysteresis of less than 40 mV at 2.0 mA cm−2. The good electrochemical performance is ascribed to the stable self-supporting array structure for the storage of Li and abundant lithiophilic active sites for uniform Li electrodeposition in NCRA host matrix. Therefore, the dendritic growth of Li is effectively inhibited. This study provides a promising self-supporting lithiophilic NCRA as host material of Li anode to promote practical application in next-generation lithium-metal based batteries.