Wireless charging via atmospheric electrostatic induction in supercapacitive MXene: Huge energy-capture, sensitive electric-field- and proximity-sensing

The wire electrical conduction is a traditional method to transfer carriers from external circuit into internal functional materials in electronic devices, yet these guest carriers suffer ineluctable dissipation on their traveling paths before contributing device performance. Hereof, a wireless electrostatic induction strategy is developed to activate native carriers just inside MXene-based electrochemical supercapacitive device for facilitating carrier utilization. Experimental and simulative results reveal that in the device domains permeated by atmospheric electric field, the native carriers are effectively excited not only in porous MXene material, but also in metallic foil substrate and ionic electrolyte, endowing a huge energy capacity of 541.6 F g   −   1 , greatly larger than 258.5 F g   −   1 implemented by wire conductive charge. Further, the inducing system is explored to detect the atmospheric electric field strength with the highest sensitivity of 14.42 m μA V   −   1 and high linearity of 95.22% in ranging 0–1100 V m   −   1 and is also utilized to sense contactless proximity stimulus with a high sensitivity of 7.01 μA m   −   1 and high linearity of 97.9% in penetration depth ranging 0∼20 cm. These smart functions are also realized with prototype equipment for applicable exploration.