Based on the water-in-salt system, VOC is used as the cathode of the chloride ion batteries

Chloride ion batteries (CIBs) are considered promising candidates in the field of batteries. Safety concerns are a major issue in battery technology, which can be effectively addressed by using water-in-salt electrolyte. However, traditional CIBs suffer from issues such as poor lifespan and low cycling capacity. Therefore, our research proposes a novel aqueous CIB composed of a VOC (Vanadium pentoxide doped with graphite) cathode, a zinc anode, and (CH 3 ) 4 NCl + LiCl aqueous electrolyte for the first time. The developed battery boasts advantages such as low cost, arbitrary folding, lightweight design, and overall safety. The battery exhibits a high discharge platform of approximately 2.5V and considerable discharge capacity, reaching a maximum of 3.49mAh cm −2 at a current density of 1A g −1 . After 200 cycles, the capacity retention rate remains around 77 %. Notably, the battery is very simple to fabricate and burn in flames at a temperature of 1300 °C without explosion. And it is also able to work normally when subjected to folding, rolling, and piercing. This low-cost, flexible, and safe novel aqueous chloride-ion battery holds great application potential in portable devices, automotive, military, and other industries, opening up new possibilities for the future development of batteries.