Homologous Strategy to Construct High?Performance Coupling Electrodes for Advanced Potassium?Ion Hybrid Capacitors

• 作者: Chu Liang Haiwen Li Hao Sun Jiafeng Ruan Junhe Yang Shiyou Zheng Ying Xu Yuepeng Pang
• 来源期刊: 纳微快报（英文）
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: Energy Conversion and Storage (Battery, Supercapacitor)
• 页码范围: 289-302
• 页数: 14页
• 语种: 英文

摘要

Potassium-ion hybrid capacitors (PIHCs) have been considered as promising potentials in mid- to large-scale storage system applications owing to their high energy and power density. However, the process involving the intercalation of K+ into the carbonaceous anode is a sluggish reaction, while the adsorption of anions onto the cathode surface is relatively faster, resulting in an inability to exploit the advantage of high energy. To achieve a high-performance PIHC, it is critical to promote the K+ insertion/desertion in anodic materials and design suitable cathodic materials matching the anodes. In this study, we propose a facile "homologous strategy" to construct suitable anode and cathode for high-performance PIHCs, that is, unique multichannel carbon fiber (MCCF)-based anode and cathode materials are firstly prepared by electrospinning, and then followed by sulfur doping and KOH activation treatment, respectively. Owing to a multichannel structure with a large interlayer spacing for introducing S in the sulfur-doped multichannel carbon fiber (S-MCCF) composite, it presents high capacity, super rate capability, and long cycle stability as an anode in potassium-ion cells. The cathode composite of activated multichannel carbon fiber (aMCCF) has a considerably high specific surface area of 1445 m2 g- 1 and exhibits outstanding capacitive performance. In particular, benefiting from advantages of the fabricated S-MCCF anode and aMCCF cathode by homologous strategy, PIHCs assembled with the unique MCCF-based anode and cathode show outstanding electrochemical performance, which can deliver high energy and power densities (100 Wh kg- 1 at 200 W kg-1, and 58.3 Wh kg- 1 at 10,000 W kg-1) and simultaneously exhibit superior cycling stability (90％ capacity retention over 7000 cycles at 1.0 A g- 1). The excellent electrochemical performance of the MCCF-based composites for PIHC electrodes combined with their simple construction renders such materials attractive for further in-depth investigations of alkali-ion battery and capacitor applications.