Researchers in China have pioneered a formula for a nontoxic "aqueous battery" that they say could last 10 times longer than today's best devices. What's more, the water battery achieves this epic lifespan without degrading and can be disposed of safely in the environment, the team reported in a new study.

For the new method, researchers used synthesized covalent organic polymers (COPs). These tough, organic molecules, such as nitrogen and carbon, are bound together in a tight structure with clear openings and are used as an anode for magnesium and calcium ions.

Organic polymers like this have little use because they are generally short-lived in aqueous batteries; they break down quickly in water-based electrolytes found inside this variant of battery, which can be either extremely acidic or extremely alkaline. The electrolyte is essential to moving ions between the anode and the cathode, which is why aqueous batteries are a nonflammable and more affordable alternative to traditional batteries.

https://www.livescience.com/technology/engineering/new-water-battery-could-last-until-the-24th-century-and-it-can-be-safely-discarded-in-the-environment