MnO2 nanosheet modified N, P co-doping carbon nanofibers on carbon cloth as lithiophilic host to construct high-performance anodes for Li metal batteries

Lithium (Li) metal batteries have attracted much attention owing to its ultra-high energy density. However, as important part of Li metal batteries, Li anodes still face many challenges, mainly including uncontrolled dendritic Li formation, dramatical volume variation and serious pulverization. Herein, manganese dioxide (MnO2) nanosheet modified nitrogen (N), phosphorus (P) co-doping carbon nanofibers (NPC) on carbon cloth (CC) (MnO2@NPC-CC) is successfully fabricated through electrodeposition approach and further treated with Li by the molten-infusion method to prepare Li based Mn@NPC-CC (Li-Mn@NPC-CC) electrode. The synergy of MnO2 and NPC obviously increases the reaction rate between MnO2@NPC-CC and Li and guides even Li distribution over infusion process. Additionally, theoretical calculation, simulation and experimental results further indicate that N, P, Mn multi-doping effectively improves the superior lithiophilicity of Li-Mn@NPC-CC, which induces uniform Li deposition/dissolution to suppress dendrite growth over cycles. Moreover, conductive and porous NPC matrix not only effectively improves the stability of Li-Mn@NPC-CC, but also provides abundant spaces to accelerate the transfer of ion/electron and buffer electrode dimension variation during cycling. Hence, Li-Mn@NPC-CC-based symmetric cells exhibit extra-long cycling life (over 2200 h) with small hysteresis of 20 mV. When the LiMn@NPC-CC anode couples with air, Li iron phosphate (LiFePO4), or hard carbon (C) cathode, the assembled full cells exhibit outstanding performance with low hysteresis and stable cycling properties. Especially, the corresponding pouch-typed Li-air cells also exhibit good performance at different bending angles and even power a series of electronic devices. (C) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences Published by Elsevier B.V. All rights reserved.