A Usage Scenario Independent “Air Chargeable” Flexible Zinc Ion Energy Storage Device

A rationally designed “air chargeable” energy storage device is demonstrated, which can be effectively charged by harvesting pervasive energy from the ambient environment. For an “air chargeable” zinc-ion capacitor system, the system simply consists of a flexible bifunctional “U” shaped electrode (with the functions of energy harvesting and storage), a zinc metal electrode in middle, and two different polyelectrolytes (polyacrylamide and sodium polyacrylate) sandwiched between the zinc metal and “U” shaped electrode. When the zinc-ion capacitor is exhausted, it can be quickly charged to 88% within 10 min by simply opening the sealing tape and allowing the air diffuse in. The capacitor exhausting-air charging processes are repeated 60 times and the whole system works well. When the external power supplier is available, both the zinc-ion capacitor and “air charging” component can be fully recovered. A large capacity (≈1000 mAh) “air chargeable” zinc-vanadium battery is also demonstrated. The zinc-vanadium battery can be fully charged by air in 1 h. This work offers a usage scenario independent reliable self-chargeable power supply system as a promising approach to solve the intermittent and unpredictable nature of currently developed self-chargeable devices.