'Water batteries' are cheaper, recyclable and do not explode

By replacing the dangerous chemical electrolytes used in conventional batteries with water, scientists create a recyclable "water battery" .

Metal-water ion battery prototype - (Photo: RMIT University).

The official name of "water battery" is metal-ion water battery . This type of battery uses metals such as magnesium or zinc, which are cheaper and less toxic than materials currently used in other types of batteries. 

In a water battery, the electrolyte is water with a little salt added instead of sulfuric acid or lithium salt.

In particular, the research team found a way to prevent the short circuit phenomenon of water batteries - which occurs when metal fibers called dendrite appear in the battery , by covering the battery's cathode with bismuth metal to prevent the dendrite formation.

The research team's experiments showed that this method also helps the prototype water battery operate longer, maintaining more than 85% of its capacity after 500 charging cycles. 

According to ScienceAlert on March 5, the team has so far developed water battery prototypes of coin-sized batteries used in watches as well as cylindrical batteries similar to AA or AAA batteries.

Research team leader Tianyi Ma, a scientist at RMIT University in Melbourne (Australia), said that although new technology is unlikely to replace lithium-ion batteries soon, with further research and development, water batteries can become a safe alternative within a decade or more.

Lithium-ion batteries, found in everything from laptops to phones to motorbikes and electric bicycles, can overheat and catch fire in some cases.