High-capacity sodium ion battery anodes based on CuO nanosheets and carboxymethyl cellulose binder

Abstract

CuO nanosheets prepared by a hydrothermal treatment were tested as anode material for sodium-ion batteries (SIBs) with aid of different binders, namely carboxymethyl cellulose (CMC) and poly (vinylidene) fluoride (PVDF). Compared with electrode containing PVDF, CuO nanosheets electrode with CMC binder showed significantly more satisfactory electrochemical performance. Specifically, CuO nanosheets electrodes with CMC binder delivered a high reversible capacity of 627.2 mAh g⁻¹ at 50 mA g⁻¹, and 73.4% of initial capacity value at a high current density of 2000 mA g⁻¹ after 100 cycles. According to the morphological characterisation after cycling, compared with PVDF, CMC binder better preserved the structural integrity of the anode and accommodated the volume variation of CuO nanosheets during charge/discharge cycling, thus leading to a more satisfactory electrochemical performance. Furthermore, to explore the practical application of CuO nanosheets anode, a SIB full cell consisting of CuO nanosheets anode and Na₃V₂(PO₄)₃ cathode was assembled and tested.

Keywords:

• CuO nanosheet
• sodium ion battery
• Na⁺ full cell
• binder