New water batteries could be the future of the energy industry

‘Water and electricity should never mix,’ is not a rule a global team of researchers and industry collaborators led by RMIT University are living by as they invent a new recyclable ‘water battery’. The new invention that won’t catch fire or explode like other problematic batteries on the market could change the entire battery industry. 

At present, Lithium-ion batteries dominate the energy storage market but are limited in terms of large-scale grid energy storage due to safety concerns over the volatile materials they contain. 

The team led by RMIT have used water to replace organic electrolytes, to enable the flow of electric current between the positive and negative terminals, which means their batteries can’t independently combust or explode, unlike lithium-ion batteries. “What we design and manufacture are called aqueous metal-ion batteries – or we can call them water batteries,” said lead researcher professor Tianyi Ma. 

Professor Ma also commented on the simple manufacturing processes of the new water batteries which makes mass production feasible. “Our batteries can be safely disassembled and the materials can be reused or recycled,” Ma said. 

“We use materials such as magnesium and zinc that are abundant in nature, inexpensive and less toxic than alternatives used in other kinds of batteries, which helps to lower manufacturing costs and reduces risks to human health and the environment.”

Read more from the RMIT news article

Energy storage potential

Water batteries are rapidly demonstrating their potential to rival traditional lithium-ion solutions. Researchers have steadily tackled challenges like limited energy storage capacity and lifespan. Recent breakthroughs, published in Advanced Materials, include the use of a bismuth and rust coating to prevent troublesome dendrite formations that limit battery life. This development significantly extends a water battery’s usable lifespan, bringing it closer to the performance of commercial lithium-ion batteries – making water-based storage ideal for intensive real-world use.

The energy storage density of these batteries is also increasing. Using magnesium-ion construction, researchers have achieved energy densities of 75 watt-hours per kilogram – impressive progress toward the levels offered by modern Tesla batteries.  A publication in Small Structures outlines this work, and researchers are focusing on advanced nanomaterials within the electrodes to increase  density further. Experts like Professor Tianyi Ma see magnesium as the ideal material for water batteries, eventually replacing lead-acid and even lithium-ion solutions due to its lighter weight, energy potential, faster charging, and power delivery characteristics.

Potential applications

Water batteries hold immense potential for revolutionising energy storage, particularly on a large scale. Their safety advantages make them ideal for integrating into power grids and supporting the growth of renewable energy sources like solar and wind. As the technology continues to improve, the potential extends beyond the power grid; water batteries could feasibly power homes and personal devices.  This versatility, combined with their inherent safety, could reshape how we store and consume energy.