In situ constructing fluorine/nitrogen-enriched interface on highly lithiophilic carbon fiber/MXene/ZnS skeleton for stable lithium anodes

Metallic lithium (Li) is an excellent electrode material for high-energy-density batteries; however, the continuous growth of Li dendrites and the poor deposited volume consistency of Li severely influence the stability of Li anodes. Herein, a LiF-Li3N/LiNxOy-enriched SEI is prepared in situ using a strongly lithiophilic 3D carbon fiber/MXene/ZnS (CMZ) skeleton. Multiscale in situ and ex situ characterizations reveal the mechanisms for Li nucleation and growth on the CMZ skeleton, proving that Li grows tightly over CMZ fibers. This behaviour is attributed to the CMZ skeleton, which provides abundant atomic-level active sites for the uniform and dense nucleation of Li. Electrochemical tests confirm that SEI enriched with LiF-Li3N/LiNxOy can effectively improve Li deposition kinetics, ensure uniform mass transfer and rapid migration of lithium ions in the SEI, and guarantee uniform growth of Li. Consequently, a half cell with a Li-CMZ electrode delivers a high Coulombic efficiency (99.83 %), an ultralong cycling life (17860 h), and an excellent rate performance (30 mA cm−2). Moreover, full cells consisting of a Li-CMZ anode and different cathodes exhibit superior cycling stabilities. For Li-CMZ ‖ LiFePO4 pouch cell, 84 % capacity is maintained after 300 cycles at 1 C.