Engineering Small-Sized Cations with Strong Solvation for High-Voltage Supercapacitors

Authors

• Tong Huo, College of Materials Science and Engineering, Tianjin Key Laboratory of Advanced Fibers and Energy Storage, Tiangong University, Tianjin 300387, China
• Pan Liu, College of Materials Science and Engineering, Tianjin Key Laboratory of Advanced Fibers and Energy Storage, Tiangong University, Tianjin 300387, China
• Hao Chen, College of Materials Science and Engineering, Tianjin Key Laboratory of Advanced Fibers and Energy Storage, Tiangong University, Tianjin 300387, China
• Peng Zhang, College of Materials Science and Engineering, Tianjin Key Laboratory of Advanced Fibers and Energy Storage, Tiangong University, Tianjin 300387, China
• Zhen-Lei Chen, College of Materials Science and Engineering, Tianjin Key Laboratory of Advanced Fibers and Energy Storage, Tiangong University, Tianjin 300387, China
• Guo-Fu Sun, College of Materials Science and Engineering, Tianjin Key Laboratory of Advanced Fibers and Energy Storage, Tiangong University, Tianjin 300387, China
• Zhi-Qiang Shi, College of Materials Science and Engineering, Tianjin Key Laboratory of Advanced Fibers and Energy Storage, Tiangong University, Tianjin 300387, ChinaFollow
• Jing Wang, College of Materials Science and Engineering, Tianjin Key Laboratory of Advanced Fibers and Energy Storage, Tiangong University, Tianjin 300387, China

Corresponding Author

Zhi-Qiang Shi ([email protected])

Abstract

Supercapacitors (SCs) have attracted much attention in the field of energy storage due to their high power density and long cycle life. However, their relatively low energy density limits their application in a wider range of fields. Methods to increase energy density include enhancing specific capacitance and extending operating voltage window. Herein, we report a novel electrolyte salt, tetramethylammonium bis(fluorosulfonyl)imide (TMA-FSI), the resulting electrolyte formed with propylene carbonate (PC), designated as TMF, exhibited a wide electrochemical stability window (ESW) of 5.09 V. On the one hand, we found that the small size of TMA⁺ enables it to enter the pores more fully during charging and discharging, thereby increasing the specific capacitance. On the other hand, the strong solvation of TMA⁺ and PC inhibited the decomposition of PC, thereby broadening the ESW. After 10,000 cycles at a current density of 2 A·g^–1 and a voltage of 3.0 V using the TMF electrolyte, the capacity retention rate of the SCs was still 96.66%, verifying the efficient kinetic characteristics of the strong solvation system.

Graphical Abstract

Keywords

Electrolyte, Solvation, Small-sized cation, High voltage, supercapacitor

DOI Link

https://doi.org/10.61558/2993-074X.3621

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Date

2026-09-28

Online Available Date

2026-06-23

Revised Date

2026-05-28

Received Date

2026-04-22

Recommended Citation

Tong Huo, Pan Liu, Hao Chen, Peng Zhang, Zhen-Lei Chen, Guo-Fu Sun, Zhi-Qiang Shi, Jing Wang. Engineering Small-Sized Cations with Strong Solvation for High-Voltage Supercapacitors[J]. Journal of Electrochemistry, 2026, 32(9): 2604271.
DOI: 10.61558/2993-074X.3621
Available at: https://jelectrochem.xmu.edu.cn/journal/vol32/iss9/3