Preparation and lithium storage properties of free-standing and three-dimensional porous Cu@SnO₂ membrane electrode

Abstract

In order to solve the problem of the low load of nano active materials in traditional electrodes, the free-standing and three-dimensional porous Cu@SnO2(3DCu@SnO2) membrane electrode with high loading capacity was obtained by nonsolvent induced phase separation method and reduction/sintering process to inherit the three-dimensional porous structure of polymer membrane. The morphology, structure and electrochemical properties of free-standing membrane electrodes were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD) analysis and electrochemical workstations. The effects of material ratio and sintering temperature on the structure and properties of self-supporting membrane electrodes were clarified. The results show that the membrane electrode with 60%(mass fraction,the same below) copper powder sintered at 600 ℃ has three-dimensional bicontinuous porous structure with SnO2 loading up to 30%. At the current density of 100 mA·g-1, the reversible specific capacity can reach 715 mAh·g-1, and remains 433.9 mAh·g-1 after 50 cycles. The specific capacity retention rate can reach 72% when the current density increases to 600 mA·g-1. The resistance of the 3DCu@SnO2 membrane electrode is 70% lower than that of traditional coating electrode.

Keywords

• nonsolvent induced phase separation
• three-dimensional bicontinuous and porous structure
• sno₂
• membrane electrode