A flexible self-charging sodium-ion full battery for self-powered wearable electronics

Novel portable power sources featuring high flexibility, built-in sustainability and enhanced safety have attracted ever-increasing attention in the field of wearable electronics. Herein, a novel flexible self-charging sodium-ion full battery was feasibly fabricated by sandwiching a BaTiO 3 -P(VDF-HFP)-NaClO 4 piezoelectric gel-electrolyte film between an advanced Na 3 V 2 (PO 4 ) 3 @C cathode and hard carbon anode. Besides the considerable flexibility and electrochemical storage performance, the as-designed device also delivers sound self-charging capability via various stress patterns, regardless of whether under static compression, repeated bending or continuous palm patting. Serially connected self-charging devices are able to drive several electronic devices with a good working state. Specifically, a unique theory of electromagnetic fields was successfully introduced to deduce the direct self-charging mechanism, where no rectifier was applied and the battery was charged by the built-in piezoelectric component. This work presents an innovative approach to achieve a new sustainable, safe and flexible sodium-ion battery for self-powered wearable electronics. Herein, a flexible self-charging sodium-ion full battery was creatively fabricated. The device shows high efficiency of energy collection, conversion and self-charging, which provide a promising potential toward sustainable wearable electronics.