Three-dimensional porous Co3O4–CoO@GO composite combined with N-doped carbon for superior lithium storage

Abstract

Transition metal oxides (TMOs) as anode materials have potential for lithium-ion batteries (LIBs). However, the poor rate capacity and cycle stability restrict its application. Herein, we demonstrate a facile one-step hydrothermal method to construct a three-dimensional porous conductive network structure, which consists of thin-layered graphene, ultrafine Co3O4–CoO nanoparticles and nitrogen-doped carbon. This unique structure can effectively prevent particle agglomeration and cracking caused by volume expansion, provide fast passage for lithium ion/electron transport during cycling and improve the electrical conductivity of the electrode. Moreover, the electrochemical kinetic analysis proves that this is a process dominated by pseudocapacitive behavior. Consequently, the N-C@Co3O4–CoO@GO hybrid electrode delivers an ultrahigh capacity of 1 273.1 mA h g−1 at 0.1 A g−1 and superior rate performance (725.1 mA h g−1 at 5 A g−1). Additionally, it exhibits a high reversible cycling capacity of 787.4 mA h g−1 at 1 A g−1 over 600 cycles and even maintains excellent cycling stability for a ultra-long cycles at 5 A g−1. This work provides a feasible strategy for fabricating the N-C@Co3O4–CoO@GO composite as a promising high-performance TMOs anode for LIBs.