Wearable and portable self-powered units have stimulated considerable attention in both the scientific and technological realms. However, their innovative development is still limited by inefficient bulky connections between functional modules, incompatible energy storage systems with poor cycling stability, and real safety concerns. Herein, we demonstrate a flexible solar-charging integrated unit based on the design of printed magnesium ion aqueous asymmetric supercapacitors. This power unit exhibits excellent mechanical robustness, high photo-charging cycling stability (98.7% capacitance retention after 100 cycles), excellent overall energy conversion and storage efficiency (ηoverall = 17.57%), and outstanding input current tolerance. In addition, the Mg ion quasi-solid-state asymmetric supercapacitors show high energy density up to 13.1 mWh cm−3 via pseudocapacitive ion storage as investigated by an operando X-ray diffraction technique. The findings pave a practical route toward the design of future self-powered systems affording favorable safety, long life, and high energy.
|Original language||English (US)|
|State||Published - Oct 31 2019|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was financially supported by the National Natural Science Foundation of China (51702225), National Key Research and Development Program (2016YFA0200103), and Natural Science Foundation of Jiangsu Province (BK20170336). The authors also acknowledge support from the Suzhou Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies, Suzhou, China and the Dr. Myung Ki Hong Chair in Materials Innovation (to R.B.K.).