Morphology controllable fabrication of lotus-like 3D porous carbon with oxygen doping for aqueous Zn-ion storage

• Published in: Carbon (New York) 2024-06, Vol.227, p.119283, Article 119283
• Main Authors: Chu, Qian, Chen, Zhizhou, Cui, Changyu, Li, Zhuangzhuang, Li, Xiao, Xu, Yanbin, Li, Yulin, Cui, Yuming, Liu, Qing
• Format: Article
• Language: English
• Subjects: 3D porous carbon; adsorption; capacitance; carbon; electrochemical capacitors; energy density; High specific capacity; hulls; Lotus; mass transfer; oxygen; Oxygen founctional groups; surface area; Zn-ion hybrid supercapacitors
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2024.119283

Designed porous structure coupling with proper functional groups are of great importance in enhacing Zn-ion hybrid supercapacitors (ZIHSs) and the long-term cycling life. Herein, a biomass-derived three-dimensional (3D) porous carbon (LSPC-2) with lotus like network structure and oxygen containing groups was prepared by using lotus husk as precursor via a combination utilization of hydrothermal and KOH activation. The as assembled Zn//LSPC-2 ZIHSs exhibit remarkable overall performance, including a high specific capacity of 212 mA h g−1 at 0.1 A g−1, an impressive energy density of 124 Wh kg−1 at 34 W kg−1, and an exceptionally long cycle life (with 97% capacitance retention after 10,000 cycles at 10 A g−1). These outstanding characteristics primarily result from the unique 3D carbon frame structure, rich in CO functional groups and large specific surface area, providing a concise mass transfer pathway, rapid kinetics, enhanced conductivity, and enlarged Zn2+ adsorption sites. Charge-discharge process mechanism studies show that the reversible chemical adsorption of Zn2+ occur on the CO and COOH functional groups, thereby markedly augmenting the pseudocapacitance contribution. [Display omitted] •The 3D network porous carbon was designed and prepared by lotus house.•Lotus house based porous carbons was firstly used as the cathode for ZIHSs.•For ZIHSs, LSPC-2 showed a high capacity of 212 mA h g−1 at 0.1 A g−1.•The storge mechanism of LSPC-2 for ZIHSs was investigated by Ex-characterizations.