Three-dimensional porous N-doped graphitic carbon framework with embedded CoO for ultrahigh and stable lithium storage

Abstract

A three-dimensional porous N-doped graphite carbon framework embedded with cobalt oxide (CoO@N-GCs) was prepared using a simple polymer heat treatment method. This material is utilized as an anode material for lithium-ion batteries (LIBs). The experimental results demonstrate that the CoO@N-GC-400 shows outstanding performance. The first capacity is 1628 mAh g−1 (0.05 A g−1) and exhibits excellent cycle characteristics, maintaining a capacity of 352.72 mAh g−1 after 1000 cycles at 1 A g−1. During pyrolysis, the interconnected macroporous structure is mostly preserved, and the formation of the macropores happens perpendicular to the surface. This occurrence is mainly due to the high-temperature carbonization of PVP and the significant pore formation resulting from the breakdown of Co(NO3)3. The pore wall undergoes a solid-to-hollow transformation due to the formation of CoO nanoparticles within the walls. This provides a useful approach for designing the anode structure of high-performance LIBs.