High-Performance Zinc-Ion Hybrid Supercapacitor from Guilin Sanhua Liquor Lees-Derived Carbon Materials

Abstract

Aqueous zinc-ion hybrid supercapacitors (ZHSCs) have attracted considerable attention because they are inexpensive and safe. However, the inadequate energy densities, power densities, and cycling performance of current ZHSC energystorage devices are impediments that need to be overcome to enable the further development and commercialization of this technology. To address these issues, in this study, we prepared carbon-based ZHSCs using a series of porous carbon materials derived from Sanhua liquor lees (SLPCs). Among them, the best performance was observed for SLPC-A13, which exhibited excellent properties and a high-surface-area structure (2667 m 2 g −1 ) with abundant micropores. The Zn//SLPC-A13 device was assembled by using 2 mol L −1 ZnSO 4 , SLPC-A13, and Zn foil as the electrolyte, cathode, and anode, respectively. The Zn//SLPC-A13 device delivered an ultrahigh energy density of 137 Wh kg −1 at a power density of 462 W kg −1 . Remarkably, Zn//SLPC-A13 retained 100% of its specific capacitance after 120,000 cycles of longterm charge/discharge testing, with 62% retained after 250,000 cycles. This outstanding performance is primarily attributed to the SLPC-A13 carbon material, which promotes the rapid adsorption and desorption of ions, and the charge−discharge process, which roughens the Zn anode in a manner that improves reversible Zn-ion plating/stripping efficiency. This study provides ideas for the preparation of ZHSC cathode materials.