Three-dimensional TiO2 nanowire@NiMoO4 ultrathin nanosheet core-shell arrays for lithium ion batteries

Abstract

This study reports a general and rational two-step hydrothermal strategy to fabricate three-dimensional (3D) TiO2 nanowire@NiMoO4 ultrathin nanosheet core-shell arrays (TNAs-NMO) as additives-free anodes for lithium-ion batteries (LIBs). The TNAs-NMO electrode delivers a reversible capacity of up to 446.6 mA h g−1 over 120 cycles at the current density of 0.2 A g−1 and a high rate capacity of 234.2 mA h g−1 at 2.0 A g−1. Impressively, the capacity retention efficiency is 74.7% after 2500 cycles at the high rate of 2.0 A g−1. In addition, the full cell consisting of TNAs-NMO anode and LCO cathode can afford a specific energy of up to 220.3 W h kg−1 (based on the entire mass of both electrodes). The high electrochemical performance of the TNAs-NMO electrode is ascribed to its 3D core-shell nanowire array architecture, in which the TiO2 nanowire arrays (TNAs) and the ultrathin NiMoO4 nanosheets exhibit strong synergistic effects. The TNAs maintain mechanical integrity of the electrode and the ultrathin NiMoO4 nanosheets contribute to high capacity and favorable electronic conductivity.