超级电容器具有功率密度大、循环寿命长等优点,但同时面临着能量密度低等缺点.胶体离子超级电容器是最近开发的一种新型赝电容器,同时具有高功率密度和高能量密度的特点.胶体离子超级电容器能够充分利用多价态金属阳离子的多电子氧化还原反应,完全释放储存的潜在电能,从而提高超级电容器的能量密度.由于胶体离子的存在,缩短了电子、离子的扩散长度,加快了氧化还原反应动力学,从而保持高的功率密度.本文主要介绍胶体离子超级电容器的发展过程、最新研究进展以及需要进一步开展的研究工作,作者希望从一个新的角度去研究发展下一代高性能电化学储能设备,实现新的突破.
Supercapacitors have high power density and long cycle life compared with battery systems, but they still suffer from low energy density at the same time. In order to increase the energy density of supercapacitors, a new type of pseudocapacitor so called colloidal ion supercapacitor has been developed. The colloidal ion supercapacitor can directly use commercial metal salts as electrode materials and the electroactive species can be formed by in-situ electrochemical reactions without the need of additional materials synthesis processes. Colloidal ion supercapacitor can fully utilize the redox reaction of metal cations with multiple oxidation states, which can completely release the stored electrical energy of multiple-valence cations, leading to high energy density.Due to the presence of colloidal cation ions in the colloidal ion supercapacitor, the diffusion lengths of electrons and ions can be shortened, leading to high redox reaction kinetics and high power density. Both high energy density and high power density can exist in one supercapacitor device, i.e., colloidal ionic supercapacitor. This review outlines the concept, basis and the development of colloidal ion supercapacitors, as well as the latest research progresses and future challenges. The colloidal ion supercapacitor is expected to advance the development in the next generation of high-performance electrochemical energy storage devices.