Scientists have invented a new “water battery” that they say won’t catch fire or explode like their popular lithium-ion counterparts and could replace them entirely within a decade.
Lithium-ion batteries dominate the energy storage market due to their ability to pack a lot of power into a small space.
But their green credentials as means of storing excess electricity from wind and solar plants has been tarnished by infrequent but eye-catching safety incidents, with the general public increasingly suspicious of having huge batteries near to their homes.
A global team of scientists led by RMIT University in Melbourne, Australia, believe they have created a safer “aqueous metal-ion” alternative.
“We can call them water batteries,” said lead researcher, Tianyi Ma, a distinguished professor at the university in a press release issued on Thursday by RMIT.
His team has used water to "replace organic electrolytes – which enable the flow of electric current between the positive and negative terminals," said RMIT. This means the batteries stay "cool under pressure," meaning they won't "start a fire or blow up – unlike their lithium-ion counterparts."
The team used materials such as magnesium and zinc that Ma said are “abundant in nature, inexpensive and less toxic than alternatives used in other kinds of batteries.”
This helps to “lower manufacturing costs and reduces risks to human health and the environment.”
The team has made a series of small-scale trial batteries for various studies. In their most recent work, RMIT said they have “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.”
This means the batteries now last “significantly longer” than lithium-ion batteries, “making them ideal for high-speed and intensive use in real-world applications.”
The team also claims to have integrated its battery with solar panels, showing they can be an “efficient and stable” solution for renewable energy storage.
Ma said the team’s batteries were well suited for large-scale applications, making them ideal for storing excess energy from intermittent renewable energy sources.
As the world looks to triple its renewable energy capacity by 2030, energy storage solutions such as this will be crucial for helping bring more wind and solar plants online.
The energy density of the battery – how much power they can pack into a certain space – is still a way off lithium-ion batteries, which lead the market in this regard.
The team said that a magnesium-ion water battery they made had up to 30% the energy density of the latest Tesla car batteries.
They will now try and increase the energy density of the batteries by “developing new nano materials as the electrode materials.”
The team believes that their magnesium-ion bater batteries have the “potential to replace” lead-acid batteries, which are safer than lithium-ion but with lower energy density, within “one to three years.”
And they could replace lithium-ion batteries “in the long term, 5 to 10 years from now.”
