Water batteries, the future of energy storage

These water batteries, distinguished by their non-flammable and explosion-resistant nature, are poised to change energy storage, presenting a viable alternative to the ubiquitous lithium-ion batteries.

What are water batteries

At the heart of this innovation lies the replacement of organic electrolytes with water, thereby eliminating the risk of fires and explosions associated with lithium-ion batteries. Lead researcher Distinguished Professor Tianyi Ma explains that what they’ve designed and manufactured are “aqueous metal-ion batteries,” aka, water batteries.

The team's resourceful approach includes the use of magnesium and zinc – abundant, inexpensive, and less toxic than other materials – which enables lower manufacturing costs and mitigate environmental risks.

A significant breakthrough is the development of a protective layer of bismuth and its oxide (rust) which is coated to affected battery parts to curb the formation of dendrites, which can cause short circuits. This advancement extends the battery's lifespan as well as aligning its performance with commercial lithium-ion batteries, making it conducive to real-world applications. The design has successfully integrated with solar panels which further enables its capability for efficient and stable renewable energy storage.

Comparison with lithium-ion batteries

While lithium-ion batteries currently dominate the market, their susceptibility to fires and environmental concerns pose significant challenges. Water batteries, with their safety and environmental benefits, offer a promising alternative.

Although lithium-ion batteries have a higher energy density, water batteries are rapidly closing this gap with Professor Ma's team achieving an energy density of 75 watt-hours per kilogram (Wh kg–1) in their magnesium-ion water batteries – comparable to up to 30% of the latest Tesla car batteries. This advancement showcases a step towards matching the compactness and efficiency of lithium-ion batteries in a safer and more sustainable manner.

Potential applications and impact

The advent of water batteries highlights a potential new future of energy storage, particularly for electric vehicles (EVs), where safety and sustainability are paramount.

With their non-flammable nature, water batteries could significantly reduce the risk of fires in EVs, enhancing vehicle safety and consumer confidence. Plus, their potential for high energy density and rapid charging could make EVs more efficient and convenient, accelerating the transition to electric mobility.

Beyond automotive applications, water batteries hold promise for large-scale grid storage and renewable energy integration. Their safety profile makes them ideal for storing excess energy from solar and wind sources, thereby facilitating a more reliable and sustainable energy supply. As these batteries become more widespread, we could also see their adoption in powering homes, electronic devices, and entertainment systems, further reducing our reliance on fossil fuels and diminishing environmental footprints.

The road ahead

As water batteries continue to evolve, their journey from laboratory breakthroughs to commercial reality is supported by peer-reviewed research, government funding, and industry engagement. Collaboration with industry partners like GrapheneX and international research institutions is crucial in addressing the complex challenges of energy storage from multiple angles.

As these batteries mature and their applications expand, they have the opportunity to play a pivotal role in driving the future of electric mobility, renewable energy integration, and more – promising a greener, safer future for our planet.