A seamlessly integrated device of micro-supercapacitor and wireless charging with ultrahigh energy density and capacitance

Nat Commun. 2021 May 11;12(1):2647. doi: 10.1038/s41467-021-22912-8.

Abstract

Microdevice integrating energy storage with wireless charging could create opportunities for electronics design, such as moveable charging. Herein, we report seamlessly integrated wireless charging micro-supercapacitors by taking advantage of a designed highly consistent material system that both wireless coils and electrodes are of the graphite paper. The transferring power efficiency of the wireless charging is 52.8%. Benefitting from unique circuit structure, the intact device displays low resistance and excellent voltage tolerability with a capacitance of 454.1 mF cm-2, superior to state-of-the-art conventional planar micro-supercapacitors. Besides, a record high energy density of 463.1 μWh cm-2 exceeds the existing metal ion hybrid micro-supercapacitors and even commercial thin film battery (350 μWh cm-2). After charging for 6 min, the integrated device reaches up to a power output of 45.9 mW, which can drive an electrical toy car immediately. This work brings an insight for contactless micro-electronics and flexible micro-robotics.