Robust and durable flexible micro-supercapacitors enabled by graphene nanoscrolls

Abstract

The rise of miniaturized, flexible and self-powered electronic systems has substantially stimulated the urgent demand for microscale electrochemical energy storage devices. Impressively, planar micro-supercapacitors (MSCs) are playing a crucial role because of fast ion transmission, ultra-long lifetime, and being easily integrated with microelectronic devices. Unfortunately, the robustness of film electrodes in MSCs usually cannot satisfy the structural stability of the film electrodes and the durability of the devices. Here, a novel strategy to address the problem is proposed by introducing graphene nanoscrolls with high aspect ratio as the active materials in the flexible MSCs to enhance the robustness of the film electrode because of their intertwined one-dimensional nanostructures. The as-prepared bendable MSC can maintain nearly 100% of initial capacitance when bent for 1000 cycles, and the stretchable MSC can maintain 88% of initial capacitance when stretched at a high stress ratio of 100% for 1000 cycles. This study provides an effective strategy to build up robust film electrodes for MSCs and improve the durability of the flexible MSCs.