Electrochemically incorporated Cu nanoparticles in NaVO3 with enhanced sodium-ion battery performance

Sodium-ion batteries (SIBs) are believed to be the promising low-cost candidates as compared to lithium-ion batteries (LIBs). Particularly, layered metal oxides show great potential as electrode materials with high capacity for SIB. However, the layered metal oxides undergo irreversible structural changes and suffer from low conductivity during charge and discharge, leading to sluggish electrochemical processes and fast capacity fading. To overcome these weaknesses, we electrochemically in-situ incorporate copper nanoparticles in NaVO3 host material during battery cycling processes, giving rise to fast electron transfer in the material matrix. The resultant copper-incorporated NaVO3 is demonstrated to have significantly increased performance for SIBs, which exhibits excellent reversible capacity, high coulombic efficiency, large capacity retention and outstanding rate capability. From ex-situ microscopy and spectroscopy characterizations, we show the evidence of the electrochemically formed Cu nanoparticles. This strategy also provides a general method to form homogeneous metal incorporation and improve the electrochemical properties for low-conductivity electrode materials.