Flexible and ion-conductive ionogel towards energy storage application

Abstract Ionogel with flexibility and ionic conductivity is a promising component of electrochemical devices. Developing flexible ionogel with high conductivity is urgent for efficient energy storage. Here, a flexible ionogel has been developed from ionic liquid and polymer substrate through simple solution casting method. The as-prepared ionogel displays good mechanical properties with high tensile modulus of 1.6 MPa and break elongation of 9.1%. And the translucent ionogel shows flexibility, which can be bended arbitrarily and tangled onto rod. In addition, the ionogel based supercapacitor gives specific capacity of 62 F g−1 at current density of 1 A g−1 with high coulombic efficiency. The supercapacitor can deliver stable energy output in wide current densities from 1 to 10 A g−1, indicating good rate capability. The device presents long cycling life with capacity retention of 86.3% over 10,000 cycles, showing great potential for practical applications. This work sheds light on the design and synthesis of ionogels for electrochemical energy storage and conversion devices.