Co-CoO/MnO Heterostructured Nanocrystals Anchored on N/P-Doped 3D Porous Graphene for High-Performance Pseudocapacitive Lithium Storage

Abstract

Lithium ion batteries (LIBs) are extensively used in numerous applications due to their impressive energy density and low memory effect. However, the inherently diffusion-controlled lithium storage limits their high-power applications. Herein, a novel surface redox capacitive lithium storage which originates from the deep oxidation of oxides during cycling of a hybrid consisting of nitrogen/phosphorous co-doped 3D graphene networks and Co-CoO/MnO nanoparticles (NPGCM), was employed to enhance the rate performance of anode for Li-ion batteries. The combination of surface pseudocapacitance with the diffusion-related lithium storage led to an extraordinary rate capability (1170.7 mAh g−1 at 0.2 A g−1 and 258.3 mAh g−1 at 6 A g−1). Furthermore, the NPGCM hybrid exhibited excellent cyclic stability, showing a capacity of 397 mAh g−1 after 1300 cycles at 4 A g−1. Electron microscopy and spectroscopic investigations suggested the pseudocapacitance is originated from Mn3O4 generated during cycling.