ABSTRACT
Iron oxides with advanced functional properties show great potential for applications in the fields of water splitting, drug delivery, sensors, batteries and supercapacitors. However, it is challenging to develop a simple and efficient strategy for fabricating patterned iron oxide based electrodes for supercapacitor applications. Herein, a facile, simple, scalable, binder-free, surfactant-free and conductive additive-free electric discharge rusting (EDR) technique is proposed to directly synthesize Fe1-xO oxide layer on a pure iron substrate. This new EDR strategy is successfully adopted to fabricate Fe-Fe1-xO integrative patterned electrodes and coplanar microsupercapacitors (CMSC) in one step. The CMSC devices with different geometries could be directly patterned by EDR, which is automatically controlled by a computer numerical control system. The fabricated Fe-Fe1-xO based 3D 2F-CMSC exhibits a maximum areal specific capacitance of 112.4 mF cm-2. Another important finding is the fabrication of 3D 2F-CMSC devices, which show good capacitive behavior at an ultra high scanning rate of 20 000 mV s-1. The results prove that EDR is a low-cost and versatile strategy for the scalable fabrication of high-performance patterned supercapacitor integrative electrodes and devices. Furthermore, it is a versatile technique which shows a great potential for development of next generation microelectronic devices, such as microbatteries and microsensors.
