Researchers have developed innovative ‘water batteries’ that offer a safe, recyclable alternative to lithium-ion batteries for large-scale energy storage. These aqueous metal-ion batteries use water instead of flammable electrolytes, preventing fire hazards. Their sustainable design facilitates easy disassembly for material reuse or recycling. Significant advancements include overcoming dendrite growth, extending battery lifespan, and achieving competitive energy densities with potential applications in grid storage and renewable energy integration. The project’s success is underpinned by global collaboration and industry partnerships, signaling a promising direction for safer and more efficient energy storage solutions. (Artist’s concept). Credit: SciTechDaily.com
A global team of researchers and industry collaborators led by RMIT University has developed recyclable ‘water batteries’ that won’t catch fire or explode.
Lithium-ion energy storage dominates the market due to its technological maturity, but its suitability for large-scale grid energy storage is limited by safety concerns with the volatile materials inside.
Lead researcher Distinguished Professor Tianyi Ma said their batteries were at the cutting edge of an emerging field of aqueous energy storage devices, with breakthroughs that significantly improve the technology’s performance and lifespan.
“What we design and manufacture are called aqueous metal-ion batteries – or we can call them water batteries,” said Ma, from RMIT’s School of Science.
The team uses water to replace organic electrolytes – which enable the flow of electric current between the positive and negative terminals – meaning their batteries can’t start a fire or blow up – unlike their lithium-ion counterparts.
“Addressing end-of-life disposal challenges that consumers, industry, and governments globally face with current energy storage technology, our batteries can be safely disassembled and the materials can be reused or recycled,” Ma said.
The simplicity of manufacturing processes for their water batteries helped make mass production feasible, he 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.”
What’s the energy storage and life-cycle potential?
The team has made a series of small-scale trial batteries for numerous peer-reviewed studies to tackle various technological challenges, including boosting energy storage capacity and lifespan.
In their latest work, published in Advanced Materials, they’ve triumphed over a major challenge – the growth of disruptive dendrites, which are spiky metallic formations that can lead to short circuits and other serious faults.
The team coated affected battery parts with a metal called bismuth and its oxide (otherwise known as rust) as a protective layer that prevented dendrite formation.
The result?
“Our batteries now last significantly longer – comparable to the commercial lithium-ion batteries in the market – making them ideal for high-speed and intensive use in real-world applications. With impressive capacity and extended lifespan, we’ve not only advanced battery technology but also successfully integrated our design with solar panels, showcasing efficient and stable renewable energy storage.”
The team’s water battery is closing the gap with lithium-ion technology in terms of energy density, with the aim of using as little space per unit of power as possible. “We recently made a magnesium-ion water battery that has an energy density of 75 watt-hours per kilogram (Wh kg-1) – up to 30% that of the latest Tesla car batteries.”
Distinguished Professor Tianyi Ma (left) and Dr Lingfeng Zhu at RMIT University with the team’s water battery. Credit: Carelle Mulawa-Richards, RMIT University
This research is published in Small Structures.
“The next step is to increase the energy density of our water batteries by developing new nanomaterials as the electrode materials.”
Ma said magnesium was likely to be the material of choice for future water batteries.
“Magnesium-ion water batteries have the potential to replace lead-SciTechDaily