Anti‐self‐discharge ultrathin all‐inorganic electrochromic asymmetric supercapacitors enabling intelligent and effective energy storage
Lei Liu, Chen Liu, Meng-Ying Wang, Bin Li, Ke Wang, Xiangqian Fan, Liyong Wang, Huiqi Wang, Shengliang Hu, Xungang Diao
Abstract
Abstract Electrochromic asymmetric supercapacitors (EASs), incorporating electrochromic and energy storage into one platform, are extremely desirable for next‐generation civilian portable and smart electronic devices. However, the crucial challenge of their fast self‐discharge rate is often overlooked, although it plays an important role in practical application. Unfortunately, very limited research on EAS has focused on this critical problem. Here, an ultrathin all‐inorganic EAS with excellent anti‐self‐discharge performance and superior electrochromic behavior is designed and manufactured by introducing a thin nano‐functional layer at the electrode/electrolyte interface. The prototype all‐inorganic EAS exhibited a wide working voltage of 2.2 V, a high energy/power density (81.2 mWh·cm −3 /0.688 W·cm −3 and 30.6 mWh·cm −3 /11.02 W·cm −3 ), along with outstanding electrochemical and electrochromic performance even at high temperatures. Remarkably, the introduced Ta 2 O 5 layer can efficiently prohibit the redistribution and diffusion of the movable ions at the fully charged state, endowing the all‐inorganic EAS with a tardy self‐discharge rate of 12.6 mV·g −1 , which is an extremely low value when compared with previous reported research. Significantly, the ultrathin all‐inorganic EASs could also well maintain a slow self‐discharge rate and their original electrochemical characteristics under various environmental temperatures. We envision that the novel strategy of electrode/electrolyte interface engineering can effectively deal with the severe self‐discharge challenge of EAS, and provide more opportunities for their practical applications.