Unique synthesis of mesoporous peapod-like NiCo2O4–C nanorods array as an enhanced anode for lithium ion batteries

Abstract

A novel peapod-like NiCo₂O₄–C nanorods array on a 3D Ni-foam was synthesized for the first time and used as an anode for lithium ion batteries. The nanorods array was grown directly on a 3D Ni-foam by a facile route, including a hydrothermal reaction and subsequent annealing at a setting temperature. In contrast to previous reports, the as-prepared peapod-like NiCo₂O₄–C composite in our experiments exhibited both mesoporosity and excellent conductivity; moreover, the stable core–shell structure allowed improved electron transfer and electrolyte penetration when applied to lithium ion batteries. When tested in an electrochemical system, the as-prepared samples demonstrated excellent electrochemical performance such as enhanced rate capability (a reversible capability of 664 mA h g⁻¹ at 2000 mA g⁻¹) as well as a high coulombic efficiency (coulombic efficiency of 97% can be obtained after 200 cycles at 100 mA g⁻¹).