Extrinsic design of high-performance programmable supercapacitor with large specific areal capacitance

The stretchable supercapacitors based on predesigned structures show low specific areal capacitance and lack programmable stretchability. To overcome the limitations, developing a programmable supercapacitor with customizable stretchability and ultrahigh areal capacitance is extremely desirable. In this study, we develop programmable supercapacitors with desirable stretchability and ultrahigh specific capacitance using interconnected polypyrrole/graphene (PPy/RGO) electrodes. Thanks to the easy accessibility of ions and high ability of ion transfer, the optimized PPy/RGO-1800 electrode achieves a specific capacitance of 1545.6 mF·cm−2, and the assembled flexible supercapacitor presents an ultrahigh stack capacitance of 45.1 F·cm−3. The stretchable supercapacitor edited by kirigami delivers a specific capacitance of 489.1 mF·cm−2 at 400% strain and keeps stable capacitive performance under various deformations (bending, stretching and torsion), which is superior to most of the reported stretchable supercapacitors. Additionally, it can keep more than 92% of initial capacitance after 1000 cycles of various large deformations. The enhanced areal capacitance and easy programmability make the stretchable supercapacitor highly promising for wearable electronics.