Energy

Green, saltwater-based battery leans on a new anode to go the distance

Green, saltwater-based battery...
Scientists have developed a new anode for saltwater-based batteries that ups their durability and lifespan
Scientists have developed a new anode for saltwater-based batteries that ups their durability and lifespan
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Scientists have developed a new anode for saltwater-based batteries that ups their durability and lifespan
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Scientists have developed a new anode for saltwater-based batteries that ups their durability and lifespan

The lithium-ion batteries that power much of the modern world may be our best solution currently, but scientists continue to experiment with their makeup in pursuit of devices that are safer and less environmentally costly (among other desirable attributes). A team at the University of Central Florida (UCF) has put forward a design that ticks these two boxes, by using seawater in place of flammable and toxic electrolytes, and a new anode to improve its durability.

Inside a battery is an electrolyte solution that carries the electrical charge between the two electrodes, the cathode and anode. Contained within this solution are solvents that are flammable, bringing the risk of fire, and also toxic, bringing the risk of environmental damage when the batteries are depleted and discarded.

A safer and greener alternative would be to use seawater as the electrolyte solution instead, and this is a technology that has seen some exciting advances in recent years. A team from the US Army Research Laboratory, for example, has been working on batteries with saltwater-based electrolytes for a number of years, and has been gradually improving their voltage to the point where they could power household appliances.

The UCF team has been pursuing a similar objective with what’s known as a water-based zinc battery. Where these devices have run into trouble, however, is the growth of zinc on the battery’s anode during operation, which negatively impacts on its durability and overall lifespan.

By using an anode coated in a zinc-manganese nano-alloy instead, the scientists believe they have found a way around this problem. This design proved stable across 1,000 hours of charging and discharging cycles under a high current, showing no signs of degradation throughout.

“We developed a durable and robust 3D electrode that can be used for seawater batteries under extreme conditions,” says study author Yang Yang. “We’ve worked on aqueous batteries and the use of seawater resources for many years, so we have expertise in the field and know where it should go.”

Yang sees possibilities in using this battery design to power underwater vehicles, but also believes that with further development the zinc-manganese alloy could also prove useful in non-water-based batteries.

The research was published in the journal Nature Communications.

Source: University of Central Florida

5 comments
CraigAllenCorson
"Yang sees possibilities in using this battery design to power underwater vehicles"
And CraigAllenCorson sees possibilities in using this battery design to power the pingers in Flight Data Recorders and Cockpit Voice Recorders. If this technology had been in use back in March of 2014, we would have found MH 370, instead of its fate remaining forever unknown.
Karmudjun
This is another metallurgical breakthrough in the approach to anode and cathode deposits. More research needed to develop longer lasting and higher functioning batteries of all designs - I like the environmental impact of the salt water electrolyte. Great to read, thanks Nick!
Bob Flint
Right at our doorstep, the will to use the natural raw materials and return them back to nature.
TechGazer
I expect that using unfiltered seawater would be a very bad idea. Since the electrolyte doesn't get 'used up', I don't see the benefit of using anything other than high-purity saline solution.

A stable zinc alloy electrode sounds pretty good though. Perhaps it will do even better with a different electrolyte.

I wonder if there are any downsides they didn't mention, such as high internal resistance or high self-discharge.
jocco
would be nice if we could build a 50 ft twin-hull boat that could be saltwater power.