A dendrite-free composite Li metal anode enabled by lithiophilic Co, N codoped porous carbon nanofibers

Lithium (Li) metal is the most promising anode material for the next-generation high-energy density battery due to its high specific capacity and low redox potential. However, its practical applications is challenged by uncontrolled Li dendrite growth and volume expansion. In this work, we propose a cobalt-enhanced nitrogen doped porous carbon nanofibers (PCNF–Co/N) with an enhanced lithiophilic property. The Co/N co-doping is achieved through pyrolysis of self-assembled Co/Zn metal-organic framework (MOF) nanosheets on carbon nanofibers (CNF). The synergistic effect between the simultaneously introduced Co and N defects not only boosts the Li affinity of pyridinic and pyrrolic N but also transfers the graphitic N into lithiophilic, providing crucial roles for uniform plating of Li. Meanwhile, the porous structure formed by Zn sublimation provides sufficient buffer space for internal stress caused by Li plating/stripping. As a result, the PCNF–Co/N@Li anode delivers a long lifespan over 1400 h with a low voltage hysteresis. When paired with a LiFePO4 cathode, the full cell demonstrates decent cyclic stability and rate capability, demonstrating the capability of PCNF–Co/N in developing composite Li-metal anode with enhanced lithiophilicity and low internal stress.