Graphene Modified Polyaniline‐Hydrogel Based Stretchable Supercapacitor with High Capacitance and Excellent Stretching Stability

Abstract Conjugated polymers have been widely adopted as active materials in hydrogel‐based stretchable supercapacitors, but the relatively low conductivity and poor structural stability limit their applications. Herein, highly conductive graphene was incorporated as a substrate to anchor polyaniline (PANI) in a hydrogel‐based stretchable electrode. Graphene not only provided an effective conducting network in the electrode, but also stabilized PANI during repeating charge‐discharge processes due to strong π‐π interaction between graphene and PANI. The obtained electrode showed high capacitance of 500.13 mF cm −2 and 100 % capacitance retention after 10000 charge‐discharge cycles. The symmetrical supercapacitor using this novel stretchable electrode showed a high capacitance of 218.26 mF cm −2 , high capacitance retention of 43 % even when stretched at 150 % strain, and no capacitance decay when stretched to 100 % and then released to 0 % repeatedly for 2000 cycles, all of which were much better than the device based on the electrode without adding graphene. Such outstanding electrochemical performance shows the great application potential of highly conductive graphene in conjugated polymer‐based stretchable energy storage devices.