Homogeneous electric field and Li+ flux regulation in three-dimensional nanofibrous composite framework for ultra-long-life lithium metal anode

Abstract

Lithium (Li) metal is considered as the best anode candidate for next-generation high-energy batteries due to its ultralow electrochemical potential and extremely high theoretical capacity. However, issues arising from the undesired growth of lithium dendrites and infinite volumetric change have seriously hindered the practical application of lithium metal batteries (LMBs). Here, we designed a super-lithiophilic amorphous zinc oxide-doped carbon nanofiber framework with uniformly-distributed and parallel multichannels (MCCNF@ZnO) to achieve the homogeneous distribution of electric field and Li+ flux. By the assistances of COMSOL Multiphysics simulations and ex-situ scanning electron microscopy, we reveal that the Li metal preferentially deposits into the porous nanochannels inside the nanofibers, followed by its even distribution on the lithiophilic surface of MCCNF@ZnO. Furthermore, the conductive multichannels of the carbon nanofiber skeleton can effectively minimize the partial current density, thereby effectively avoiding the electrochemical polarization and assisting the uniform metallic deposition. As a result, MCCNF@ZnO exhibits a stable CE over 99.2% as the substrate after 500 cycles at the current density of 1 mA cm−2. The symmetrical cell of lithium-loaded MCCNF@ZnO composite electrodes can stably operate over 3300 h at 0.5 mA cm−2, indicating the great potential of MCCNF@ZnO for stabilizing lithium metal anodes in practical applications of LMBs.