The PolyPlus lithium-water battery could someday have a huge impact on EV technology.
Time Magazine’s 2011 list of the year’s “50 Best Inventions” included one that could someday have a huge impact on EV technology. Berkeley, California-based PolyPlus holds a number of patents for advanced types of lithium-based batteries, including one called a lithium-water battery that captured Time’s imagination.
A lithium-water or lithium-air battery reacts directly with oxygen in the surrounding water or air to produce its power. This allows the battery to be smaller, lighter and cheaper to produce than a traditional lithium-ion battery. The key to making this work is a patented technology that PolyPlus calls a Protected Lithium Electrode (PLE), a membrane that allows lithium to react with water or ambient air in a controlled way – without the membrane, lithium would quickly dissolve in water, or oxidize when exposed to air.
The PolyPlus lithium-water battery has achieved an energy density of 1,300 Wh/kg, many times more than the maximum energy density of current lithium-ion batteries. These batteries, which PolyPlus plans to put on the market in 2013, should be very handy for such things as unmanned underwater EVs. However, we electric car enthusiasts are more interested in a closely related technology, the lithium-air battery, which PolyPlus claims could give an EV a range of 500 miles per charge.
“As we move aggressively to commercialize our lithium batteries, this recognition from Time Magazine reflects the progress we have made and the great potential for this technology,” said Steven Visco, PolyPlus CEO. “We are moving rapidly toward delivering batteries that last much longer and are far lighter than anything available today.”