Achieving High Volumetric Lithium Storage Capacity in Compact Carbon Materials with Controllable Nitrogen Doping

Abstract

AbstractAlthough nanostructured/nanoporous carbon and silicon‐based materials are a potential replacement for graphite as cost‐effective anodes for lithium ion batteries (LIBs), their extremely low packing density leads to considerably reduced volumetric capacities. Herein, a highly compact carbon anode material constructed from sub‐2 nm nanosized graphitic domains is reported that exhibits excellent capacity density. By introducing a coordination agent in the synthesis precursors, an unusually high concentration of N‐doping (≈26.56 wt%) is achieved, which is mainly confined at the graphitic edges with the pyrrolic‐N and pyridinic‐N configurations. As further supported experimentally and theoretically, the edge‐N dopants, particularly the pyrrolic‐N, favor both ion diffusion kinetics and lithium storage via adsorption. Based on the lithiation‐state electrode volume, the compact anode shows a capacity density of 951 mAh cmtotal−3 that is comparable with Si anodes and surpasses all reported carbon‐based anodes, revealing its potential in promoting the performance of future LIBs.