Insight into the influence of part in cattails on electrochemical performance of the porous carbon for Zn-ion storage

Abstract

Recently, biomass-derived porous carbon has gained popularity as a cathode material for Zn-ion hybrid supercapacitor (ZIHSs) due to its unique structure and heteroatoms. However, the understanding of how biomass part affects resulting carbon structure and ZIHSs performance is limited. This study utilizes cattail leaves (CLs), cattail wools (CWs), and cattail stems (CSs) as carbon sources, with each impacting carbon microstructure, morphology, specific surface area (SSA), and oxygen content. CLs-based porous carbon (CLPC) exhibits a distinct hollow tube structure with thinner walls, high oxygen content, and a large SSA, which are crucial for enhanced electrochemical performance. The aqueous Zn//CLPC ZIHSs demonstrate remarkable energy density (190 Wh kg⁻¹), specific capacity (253 mAh/g at 0.1 A/g), and cycle life (91% capacity retention over 10,000 cycles at 10 A/g). Electrochemical processes are studied through various techniques, shedding light on the relationship between cattail parts, carbon structure, and ZIHSs performance, aiding in more efficient biomass utilization.