Magnesium batteries use magnesium cations in their anodes as their active charge-transporting agents. Secondary versions are under the spotlight as possible alternatives to lithium-ion chemistry. Silver, chloride, copper, manganese dioxide, and oxygen are among possible cathodes. A Colombian renewable energy start-up has developed a cordless, rechargeable copper-magnesium torch with a salt water electrolyte.
Why Be Excited About a Salt Water Magnesium Torch?
Developers E-Dina point out that around 1.5 billion people are without electricity, or a fifth of the world’s population. They plunge into darkness after dark, and then burn combustible items for light and heat. But if they had a magnesium torch they could recharge with salty water, they might be able to study after dark, and improve the quality of their lives.
Website Dezeen explains how E-Dina developed their ‘WaterLight’ product specifically for the Wayúu people. These are indigenous tribes people living on Guajira Peninsula in the northernmost part of Colombia and northwest Venezuela. They eke out a living on the fringes of cities and on semi-arid plains, where they congregate in communities, largely passed over by mainline settlements.
I’m Interested. How Do These Waterlights Work?
Well, WaterLight converts salty water into electricity online, 24-hours a day, and under almost any circumstances. The Wayúu people are most likely to draw their water from the ocean, although in an emergency any salt water will do. The WaterLight ‘battery’ sheds illumination on demand, but also has a USB port for charging phones and other small devices.
“Once filled with water, the energy delivery is immediate,” cites Dezeen. “While solar lanterns need to transform solar energy to alternative energy to charge batteries, and they only work if there is sun.” A user fills the device with 500 milliliters of seawater – or even urine in an emergency – and this provides sufficient light for up to 45 days. E-Dina indeed has found a new way to make this feasible.
More Information
Salt Water Battery Technology Leaps Forward
Magnesium Ions Dance Through Solid Electrolyte
Preview Image: Waterlights in Action
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