Multilayered interlaced SnO2 nanosheets @ porous copper tube textile as thin and flexible electrode for lithium-ion batteries

Abstract

The flexible integrated electrode structural design is a promising strategy for improved electrochemical conductivity and mitigated volume expansion of metal oxides electrodes in lithium-ion batteries. Here, a series of SnO2 nanostructures is synthesized directly on porous copper tube textile substrate (TS) via a simple hydrothermal method and the shape-depended electrochemical properties are further investigated. As flexible electrodes with the thickness of ca. 7 μm, the interlaced SnO2 nanosheets grown on textile substrate (SnO2 NS@TS) can deliver a high reversible capacity of 0.35 mAh cm−2 at 400 μA cm−2 after 200 cycles. The multiplied capacity of 0.49, 1.13, 1.42 and 1.92 mAh cm−2 (at 200 μA cm−2) and superior rate performance are easily achieved in multilayered electrodes only with a slightly increase in impedance. It is revealed that the porous tubular framework of copper textile plays significant roles in constructing conductive network and promoting electrolyte penetration. Furthermore, benefiting from the high specific surface area, abundant pores and crystal boundaries of interlaced SnO2 nanosheets, the optimized SnO2 NS@TS electrodes are demonstrated with high lithium diffusion coefficient and capacitive effect, which boost excellent electrochemical performance. Thus, this novel electrode structural design is expected to provide useful instructions, especially for thin and flexible energy storage devices.