Advanced deformable all-in-one hydrogel supercapacitor based on conducting polymer: Toward integrated mechanical and capacitive performance

The inception of flexible supercapacitors that can work steadily under large deformation has been a research hotspot in recent years. To improve the device's stability, one needs to find innovative solutions to inevitable delaminations of electroactive components, which are resulted by relative displacement under external force. Herein, an extensive all-in-one hydrogel-based supercapacitor is designed. Based on the special physical properties of hydrogels, the polypyrrole-polyvinyl alcohol/dilute sulphuric acid-polypyrrole (PHP) sandwiched device shows the harmonious mechanical and electrical properties. When the tensile strain of PHP reaches to 110%, the areal capacitance still maintains at 90%. Similarly, the high areal capacitance retention under compression and twisting also verifies that the PPy active layer tightly permeates and adheres to the PVA-H2SO4 electrolyte layer. In addition to the fascinating mechanical properties, the undetectable contact angle reveals a superhydrophilic surface which is beneficial to provide an easy access for electrolyte ions, thus enhancing the electrochemical performance. Moreover, a stable cycle performance (97% after 10000 cycles) is obtained due to the excellent water retention ability which prevents the loss of electrolyte. The maximum extended voltage window is 1 V with the power density of 500 μW cm−2 (the energy density of 6.94 μW h cm−2). These hydrogel-based supercapacitors can be immune to the harm caused by external forces and maintain good mechanical integrity and electrochemical stability. Developing the hydrogel-based supercapacitors can provide a fresh perspective on multifunction applications and herald a new territory for flexible energy storage devices. The conceptual all-in-one hydrogel-based supercapacitor is proposed who exhibits fascinating mechanical properties and realizes an excellent cycling performance. This strategy aims to solve the delamination problem existed in electrochemical components. [Display omitted] •One strategy aimed delamination problems with the construction of an all-in-one supercapacitor.•The conceptual hydrogel-based supercapacitor investigates unique mechanical properties.•The superhydrophilic behavior with an undetectable water contact angle.•This wettability can facilitate the access of aqueous hydrated ions.•A stable cycle performance is obtained due to the excellent water retention ability.