Interwoven Nanowire Based On‐Chip Asymmetric Microsupercapacitor with High Integrability, Areal Energy, and Power Density

Abstract On‐chip microsupercapacitors (MSC) with facile fabrication procedures, high integration design, and superior performance are desired as an energy storage device for microelectronics. Hence, a novel procedure is proposed to fabricate an asymmetric microsupercapacitor (AMSC), employing interwoven nanowire (NW) network electrodes of poly(3,4‐ethylenedioxythiophene) coated titanium oxynitride (P‐TiON) and vanadium nitride (VN) NW as a cathode and an anode, respectively. The interwoven NWs with a high mass loading offer a sufficient electrochemical reaction area and rapid electron/ion transport pathway, delivering superior energy and power densities. With the LiCl/polyvinyl alcohol electrolyte, the assembled P‐TiON//VN AMSC can achieve a wide voltage window from 0 to 1.8 V with an excellent areal capacitance of 72 mF cm −2 , a high areal energy density of 32.4 μWh cm −2 (at 0.9 mW cm −2 ), an outstanding power density of 45 mW cm −2 (at 21.9 μWh cm −2 ), and a good cycling performance. Furthermore, the substrate‐free electrodes exhibit outstanding integrability, and the system on one printed circuit board including two AMSCs in series and a LED demonstrates excellent practicability.