An all-in-one sodium-ion thin-film battery with stretchable and self-chargeable functions for wearable electronics

Stretchable batteries suggest promising potential for the energy supply of wearable electronics. However, they always need to be replaced or wired for charging, interfering the continuous work of wearable electronics. Besides, deviation or delamination between the inner components under repeated deformations are also bottlenecks need to be addressed. Herein, a novel all-in-one thin-film sodium-ion battery (AFSIB) with stretchable and self-chargeable functions was designed by a simple electrospinning route. In the AFSIB, two stretchable symmetric electrode films are attached on each surface of a stretchable piezo-electrolyte film, and there is a strong interaction between the films via the close connection of fibers at the interface. When suffered from an external force, the stretchable piezo-electrolyte film can act as a nanogenerator and provide an internal potential to drive the migration of Na+ ions for electrochemical reaction and energy storage, enabling the formation of self-charging capability of AFSIB. Besides, the strong interaction between the films enables the achievement of stable "All-in-One" structure of AFSIB, which can accommodate the damages comes from repeated deformations. This work paves a new approach for developing stretchable and self-chargeable energy devices for the continuous and stable energy supply of wearable electronics.