Hierarchical porous carbon nanofibers with lithiophilic metal oxide crystalline grains for long-life Li metal anodes

Abstract The application of rechargeable lithium (Li) metal batteries holds great promise for the next-generation energy storage field. However, the development of metallic Li anode is hindered by the dendrite growth on the surface and volume expansion during cycling. Herein, a composite of ZnO/carbon nanofibers (ZnO/CNFs) is rationally designed as a lithiophilic host for the uniform Li plating/stripping. The introduction of well-dispersed ZnO crystalline grains effectively transfers the lithiophibic carbon nanofibers (CNFs) into lithiophilic. The in-situ created nanoporous structure is able to alleviate the internal stress during repeating Li plating/stripping. The interconnected 3D structure provides abundant electrolyte/Li interfaces, which is beneficial minimizing local current density. Therefore, the ZnO/CNFs@Li composite anode displays a long lifespan of 1900 h along with a low voltage hysteresis of 21.7 mV in symmetric cells at 0.5 mA cm−2. When coupled with a LiFePO4 cathode, an improved rate capability is achieved as well.