High-voltage, low-temperature supercapacitors enabled by localized “water-in-pyrrolidinium chloride” electrolyte
Peng Zhang,
Weili Zhang,
Zhengjie Wang,
Xuefei Wang,
Qingjuan Ren,
Shuai Zhang,
Yujia Wang,
Liang He,
Pan Liu,
Qingyin Zhang,
Zhiqiang Shi
Affiliations
Peng Zhang
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China; Cangzhou Institute of Tiangong University, Cangzhou 061000, China
Weili Zhang
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
Zhengjie Wang
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
Xuefei Wang
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
Qingjuan Ren
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
Shuai Zhang
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
Yujia Wang
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
Liang He
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
Pan Liu
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
Qingyin Zhang
College of Chemical Engineering and Technology, Tiangong University, Tianjin 300387, China; Corresponding authors.
Zhiqiang Shi
Tianjin Key Laboratory of Advanced Fibers and Energy Storage, College of Materials Science and Engineering, Tiangong University, Tianjin 300387, China; Cangzhou Institute of Tiangong University, Cangzhou 061000, China; Corresponding authors.
Aqueous electrolytes offer superior prospects for advanced energy storage. “Water-in-salt” (WIS) electrolytes exhibit a wide electrochemical stability window (ESW), but their low conductivity, high viscosity, and precipitation at low temperatures restrict their application. Herein, we report a novel localized “water-in-pyrrolidinium chloride” electrolyte (LWIP; 1 mol/L, N-propyl-N-methylpyrrolidinium chloride/(water and N,N-dimethylformamide, 1:4 by molality)) enabling high-voltage, low-temperature supercapacitors (SCs). The greatly improved ESW (3.451 V) is mainly attributed to the strong solvation between Cl− and water molecules, which broadens the negative stability. This water-binding mechanism is very different from that of a WIS electrolyte based on alkali metal salt. SCs using LWIP electrolytes not only yield a high operating voltage of 2.4 V and excellent capacity retention (82.8% after 15,000 cycles at 5 A g−1) but also operate stably at −20 °C. This work provides new approaches for the design and preparation of novel electrolytes.
