All Pseudocapacitive Nitrogen-Doped Reduced Graphene Oxide and Polyaniline Nanowire Network for High-Performance Flexible On-Chip Energy Storage

The rapid progress of wearable and portable electronics demands high-performance on-chip energy storage units. However, it is still challenging to fabricate high-energy and flexible microscale energy storage devices. Herein, we developed a high-performance asymmetric microsupercapacitors (AMSCs) by using all flexible pseudocapacitive electrodes of nitrogen-doped reduced graphene oxide (NRG) and polyaniline nanowire network (PANI). The NRG//PANI-AMSCs could deliver a large voltage window of 1.4 V, a superior volumetric capacitance of 102 F cm–3, areal capacitance of 14.5 mF cm–2, and outstanding energy density of 30.6 mW h cm–3. Besides, the AMSCs revealed remarkable mechanical flexibility under deforming states and presented a stability with 77% capacitance retention after 5000 cycles. In addition, the microelectrodes could be facilely tailored into various geometries and dimensions by laser cutting and assembled on versatile substrates (e.g., leaves, gloves, cloth). Therefore, these AMSCs demonstrate great potential as an on-chip energy storage unit for flexible electronics.