{"id":5532,"date":"2012-04-17T17:28:27","date_gmt":"2012-04-18T00:28:27","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=5532"},"modified":"2012-04-17T17:29:13","modified_gmt":"2012-04-18T00:29:13","slug":"a-shot-of-lithium-with-a-water-chaser-please","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/a-shot-of-lithium-with-a-water-chaser-please\/","title":{"rendered":"A Shot of Lithium with a Water Chaser, Please"},"content":{"rendered":"

Lithium<\/a>, a highly reactive metal, will fire off its electrons in a fizzy display if placed in water.\u00a0 As one source explains, \u201cThe lithium-water reaction at normal temperatures is brisk but not violent.\u201d<\/p>\n

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PolyPlus lithium\/air battery<\/p><\/div>\n

It comes as a surprise then that one lithium battery manufacturer, PolyPlus Battery Company<\/a>, insists on putting its lithium battery electrodes in H2<\/sub>O.\u00a0 The firm makes both lithium\/air and lithium\/water batteries, holds over 72 patents on its intellectual property and has recently earned, along with its partner Corning, an ARPA-E (Advanced Research Project Agency \u2013 ENERGY) grant of nearly $5 million.\u00a0 It also made Time<\/em> magazine\u2019s list of the \u201c50 Best Inventions of 2011<\/a>.\u201d\u00a0\u00a0 It will be presented as a finalist in the Edison Awards<\/a> dinner in New York City on April 26 for the Best New Product prize.<\/p>\n

Even more surprising are their performance claims, which Bruce Katz, Manager of Intellectual Property for the company, made at last April\u2019s Electric Aircraft Symposium in Santa Rosa, California.\u00a0 The potential energy density for lithium\/air batteries is around 10,000 Watt-hours per kilogram, an incentive to research those elements in energy storage.\u00a0 His videos of PolyPlus\u2019 batteries lighting LEDs under water were fascinating.<\/p>\n

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PolyPlus lithium\/air and lithium\/water battery lineup<\/p><\/div>\n

PolyPlus\u2019 unique battery with a PLE (protected lithium electrode) and compliant seal has already demonstrated 700 Wh\/kg in a 2 Amp-hour cell.\u00a0 The solid electrolyte membrane that encapsulates the electrodes \u201cis highly conductive to lithium ions, but impervious to liquids and gases,\u201d according to PolyPlus.<\/p>\n

Dunked in seawater, the lithium\/water battery, although only a primary (non-rechargeable) unit, can run hundreds of hours, feeding off the reaction between the electrode and water until the lithium is depleted.\u00a0 The discharge curve is flat until the end of the batteries ability to discharge current.\u00a0 A PolyPlus 12.8 Amp-hour, 36 Watt-hour battery demonstrated this, earning a world record in November, 2009 by demonstrating an energy density of 1,300 Wh\/kg and a power density of 700 Wh\/liter.<\/p>\n

Although they are primary cells, their longevity makes sense for powering underwater sensors or devices for naval surveillance or underwater warfare.<\/p>\n

Lithium\/air batteries by PolyPlus will be a little less energetic, but still the company hopes for commercial Li-Air batteries capable of producing around 1000 Wh\/l and 1000 Wh\/kg. \u00a0Lithium\/seawater batteries could, according to PolyPlus, be \u201cintroduced commercially at about 1,500 Wh\/l and 1,500 Wh\/kg. \u00a0Li\/Air and Li\/Seawater batteries are based on non-toxic materials and are environmentally benign.\u201d<\/p>\n

PolyPlus, combining ARPA-E funds with growing interest in its technology, seems well poised to reach plausible commercial underpinnings, something that might make electric vehicles more practical.<\/p>\n

ARPA-E\u2019s fact sheet<\/a> on these batteries is instructive and gives insight into why the government is interested in seeing these new concepts help in the struggle to gain energy security.<\/p>\n