Wu Shuilin, Yang Yibing, Sun Mingzi, Zhang Tian, Huang Shaozhuan, Zhang Daohong, Huang Bolong, Wang Pengfei, Zhang Wenjun
Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central Minzu University, Wuhan, 430074, People's Republic of China.
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, People's Republic of China.
Nanomicro Lett. 2024 Mar 25;16(1):161. doi: 10.1007/s40820-024-01372-x.
With the merits of the high energy density of batteries and power density of supercapacitors, the aqueous Zn-ion hybrid supercapacitors emerge as a promising candidate for applications where both rapid energy delivery and moderate energy storage are required. However, the narrow electrochemical window of aqueous electrolytes induces severe side reactions on the Zn metal anode and shortens its lifespan. It also limits the operation voltage and energy density of the Zn-ion hybrid supercapacitors. Using 'water in salt' electrolytes can effectively broaden their electrochemical windows, but this is at the expense of high cost, low ionic conductivity, and narrow temperature compatibility, compromising the electrochemical performance of the Zn-ion hybrid supercapacitors. Thus, designing a new electrolyte to balance these factors towards high-performance Zn-ion hybrid supercapacitors is urgent and necessary. We developed a dilute water/acetonitrile electrolyte (0.5 m Zn(CFSO) + 1 m LiTFSI-HO/AN) for Zn-ion hybrid supercapacitors, which simultaneously exhibited expanded electrochemical window, decent ionic conductivity, and broad temperature compatibility. In this electrolyte, the hydration shells and hydrogen bonds are significantly modulated by the acetonitrile and TFSI anions. As a result, a Zn-ion hybrid supercapacitor with such an electrolyte demonstrates a high operating voltage up to 2.2 V and long lifespan beyond 120,000 cycles.
凭借电池的高能量密度和超级电容器的功率密度优势，水系锌离子混合超级电容器成为了在需要快速能量输送和适度能量存储的应用中的一个有前景的候选者。然而，水系电解质狭窄的电化学窗口在锌金属阳极上引发了严重的副反应并缩短了其寿命。它还限制了锌离子混合超级电容器的工作电压和能量密度。使用“盐包水”电解质可以有效拓宽其电化学窗口，但这是以高成本、低离子电导率和狭窄的温度兼容性为代价的，这会损害锌离子混合超级电容器的电化学性能。因此，设计一种新的电解质来平衡这些因素以实现高性能锌离子混合超级电容器是迫切且必要的。我们开发了一种用于锌离子混合超级电容器的稀水/乙腈电解质（0.5 m Zn(CFSO) + 1 m LiTFSI - HO/AN），它同时展现出扩大的电化学窗口、良好的离子电导率和宽泛的温度兼容性。在这种电解质中，水合壳层和氢键受到乙腈和TFSI阴离子的显著调制。结果，具有这种电解质的锌离子混合超级电容器展示出高达2.2 V的高工作电压和超过120,000次循环的长寿命。
