Engineering CO groups in 3D hollow porous carbon for boosting Zn-ion hybrid supercapacitors

• Published in: Journal of energy storage 2024-09, Vol.98, Article 113065
• Main Authors: Chu, Qian, Chen, Zhizhou, Cui, Changyu, Zhang, Yingnan, Li, Xiao, Xu, Yanbin, Li, Yulin, Yang, Huawei, Cui, Yuming, Liu, Qing
• Format: Article
• Language: English
• Subjects: C=O; Cattail wools; Hollow porous carbon; Zn-ion hybrid supercapacitors
• ISSN: 2352-152X
• DOI: 10.1016/j.est.2024.113065

The precise design and fabrication of carbon scaffolds with exceptional Zinc affinity and stability are crucial, yet they remain formidable tasks when aiming to enhance both the supercapacitive performance and cycling-stability of Zinc-ion hybrid supercapacitors (ZIHSs). In this work, a rich in CO functional groups is reported to design hollow porous carbon for high-energy-density ZIHSs. The content of CO functional groups within the hollow porous carbon can be controlled by changing the pre‑carbonization and KOH/carbon ratio of cattail wools. The distinctive hollow porous structure facilitates increased accessibility to the embedded zincophilic sites and enhances the ion diffusion process. A charge storage mechanism is postulated, involving the electronic double-layer capacitor coupled with a multielectron redox response. As a result, the distinctive electrochemical characteristics yield noteworthy results, including an excellent energy density of 210 Wh kg−1, a superior specific capacitance of 145 mAh g−1 at 10 A g−1, an exceptional power density of 1546 W kg−1, and long-term resilience, with the system retaining 92 % of its initial capacity even after completing 10,000 cycles. Significantly, the approach of enhancing electrochemical performance by modulating the electrode pseudocapacitance is applicable to various other carbon materials as well. [Display omitted] •A rich in CO hollow porous carbon was designed and prepared.•Hollow porous tubular structure can be maintained after activation.•A mechanism for ZIHSs charge storage of CO was investigated.•For ZIHSs, CWHPC exhibited an excellent energy density of 128 Wh kg−1.•Impressive specific capacitance and ultra-long life have been attained.