Shape-Tailorable Graphene-Based Ultra-High-Rate Supercapacitor for Wearable Electronics

With the bloom of wearable electronics, it is becoming necessary to develop energy storage units, <i>e</i>.<i>g</i>., supercapacitors that can be arbitrarily tailored at the device level. Although gel electrolytes have been applied in supercapacitors for decades, no report has studied the shape-tailorable capability of a supercapacitor, for instance, where the device still works after being cut. Here we report a tailorable gel-based supercapacitor with symmetric electrodes prepared by combining electrochemically reduced graphene oxide deposited on a nickel nanocone array current collector with a unique packaging method. This supercapacitor with good flexibility and consistency showed excellent rate performance, cycling stability, and mechanical properties. As a demonstration, these tailorable supercapacitors connected in series can be used to drive small gadgets, <i>e</i>.<i>g</i>., a light-emitting diode (LED) and a minimotor propeller. As simple as it is (electrochemical deposition, stencil printing, <i>etc</i>.), this technique can be used in wearable electronics and miniaturized device applications that require arbitrarily shaped energy storage units