Water and electronics are not a good match, but researchers have found a way to use water to improve batteries. By replacing hazardous chemical electrolytes with water, scientists have developed a recyclable ‘water battery’. This new technology uses metals such as magnesium or zinc, which are cheaper to assemble and less toxic than the materials used in other batteries.
Batteries work by producing a flow of electrons that move from the positive end of the battery (the cathode) to the negative end (the anode). The fluid in the battery shuttles electrons back and forth between both ends. In a ‘water battery’, the electrolytic fluid is water with a few added salts, instead of something like sulfuric acid or lithium salt.
One of the key challenges with using water batteries is preventing them from short-circuiting. This can happen when tiny spiky metallic growths called dendrites form on the metal anode inside a battery, busting through battery compartments. To overcome this, researchers coated the zinc anode of the battery with bismuth metal, which oxidizes to form rust. This creates a protective layer that stops the formation of dendritis.
So far, the researchers have developed water-based prototypes of coin-sized batteries used in clocks, as well as cylindrical batteries similar to AA or AAA batteries. They are working to improve the energy density of their water batteries, to make them comparable to the compact lithium-ion batteries found inside pocket-sized devices.
Although the new technology is unlikely to replace lithium-ion batteries any time soon, with further research and development, water batteries could provide a safe alternative to lithium-ion ones in a decade or so. Lithium-ion batteries, which are found in everything from laptops and phones to electric bikes and cars, can overheat and catch on fire in extreme cases. This is due to the fact that lithium is quite an active metal, which is submerged in an organic electrolyte.
Lead-acid batteries, which have a low energy density, are used to start petrol or diesel car motors, and in large-scale grid energy storage. However, because they contain lead and hazardous acids, they cannot be disposed of and must be recycled at specialist facilities.
Recycling or reusing lithium-ion batteries is also a top priority given projected increases in demand for the batteries and the metals used to make them, as the world electrifies its energy systems to phase out fossil fuels and combat climate change.
Many researchers have demonstrated the practical application of their battery design by connecting it to a solar panel and a 45-watt solar light. The battery was able to keep the light illuminated for 12 hours after a full day’s charge. This experiment showcases the potential of ‘water batteries’ as a viable option for storing renewable energy and should encourage further research in this field.
This news is a creative derivative product from articles published in famous peer-reviewed journals and Govt reports:
References:
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This article highlights a game-changer in battery technology! Water batteries offer a compelling combination of safety, eco-friendliness, and affordability.