[EVDL] Safer Flow Batteries for Grid Storage
http://www.ecnmag.com/news/2015/09/rechargeable-battery-power-home-rooftop-solar-panels A Rechargeable Battery To Power A Home From Rooftop Solar Panels Thu, 09/24/2015 - 2:19pm A team of Harvard scientists and engineers has demonstrated a rechargeable battery that could make storage of electricity from intermittent energy sources like solar and wind safe and cost-effective for both residential and commercial use. The new research builds on earlier work by members of the same team that could enable cheaper and more reliable electricity storage at the grid level. The mismatch between the availability of intermittent wind or sunshine and the variability of demand is a great obstacle to getting a large fraction of our electricity from renewable sources. This problem could be solved by a cost-effective means of storing large amounts of electrical energy for delivery over the long periods when the wind isn't blowing and the sun isn't shining. In the operation of the battery, electrons are picked up and released by compounds composed of inexpensive, earth-abundant elements (carbon, oxygen, nitrogen, hydrogen, iron and potassium) dissolved in water. The compounds are non-toxic, non-flammable, and widely available, making them safer and cheaper than other battery systems. "This is chemistry I'd be happy to put in my basement," says Michael J. Aziz, Gene and Tracy Sykes Professor of Materials and Energy Technologies at Harvard Paulson School of Engineering and Applied Sciences (SEAS), and project Principal Investigator. "The non-toxicity and cheap, abundant materials placed in water solution mean that it's safe—it can't catch on fire—and that's huge when you're storing large amounts of electrical energy anywhere near people." The research appears in a paper published today in the journal Science. This new battery chemistry was discovered by post-doctoral fellow Michael Marshak and graduate student Kaixiang Lin working together with co-lead author Roy Gordon, Thomas Dudley Cabot Professor of Chemistry and Professor of Materials Science at Harvard. "We combined a common organic dye with an inexpensive food additive to increase our battery voltage by about 50 percent over our previous materials," says Gordon. The findings "deliver the first high-performance, non-flammable, non-toxic, non-corrosive, and low-cost chemicals for flow batteries." Unlike solid-electrode batteries, flow batteries store energy in liquids contained in external tanks, similar to fuel cells. The tanks (which set the energy capacity), as well as the electrochemical conversion hardware through which the fluids are pumped (which sets peak power capacity), can be sized independently. Since the amount of energy that can be stored can be arbitrarily increased by scaling up only the size of the tanks, larger amounts of energy can be stored at lower cost than traditional battery systems. The active components of electrolytes in most flow battery designs have been metal ions such as vanadium dissolved in acid. The metals can be expensive, corrosive, tricky to handle, and kinetically sluggish, leading to inefficiencies. Last year, Aziz and his Harvard colleagues demonstrated a flow battery that replaced metals with organic (carbon-based) molecules called quinones, which are abundant, naturally occurring chemicals that are integral to biological processes like photosynthesis and cellular respiration. While quinones in aqueous solution formed the negative electrolyte side of the battery, the positive side relied on a conventional bromine-bearing electrolyte that is used in several other batteries. The high performance and low cost of the technology, which Harvard has licensed to a company in Europe, hold the potential to provide scalable grid-level storage solutions to utilities. But bromine's toxicity and volatility make it most suitable for settings where trained professionals can deal with it safely behind secure fences. So the team began searching for a new recipe that would provide comparable storage advantages—inexpensive, long lasting, efficient—using chemicals that could be safely deployed in homes and businesses. Their new battery, described in a paper published today in the journal Science, replaces bromine with a non-toxic and non-corrosive ion called ferrocyanide. "It sounds bad because it has the word 'cyanide' in it," explains co-lead author Marshak, who is now assistant professor of chemistry at the University of Colorado Boulder. "Cyanide kills you because it binds very tightly to iron in your body. In ferrocyanide, it's already bound to iron, so it's safe. In fact, ferrocyanide is commonly used as a food additive, and also as a fertilizer." Because ferrocyanide is highly soluble and stable in alkaline rather than acidic solutions, the Harvard team paired it with a quinone compound that is soluble and stable under alkaline
Re: [EVDL] Safer Flow Batteries for Grid Storage
On 24 Sep 2015 at 22:03, Peri Hartman via EV wrote: > Well, if their technology gets past "vapor", it's a milestone for > distributed solar and wind generation. Probably never for EVs, except in the sense of banking PV to power them. And the devil is in the development. "More work is required and justified ..." Where have I heard that before? Oh, right, just about every battery "breakthrough." So we'll see. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to "evpost" and "etpost" addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Safer Flow Batteries for Grid Storage
Well, if their technology gets past "vapor", it's a milestone for distributed solar and wind generation. Put me down ! Peri -- Original Message -- From: "len moskowitz via EV" <ev@lists.evdl.org> To: "EVDL" <ev@lists.evdl.org> Sent: 24-Sep-15 2:47:23 PM Subject: [EVDL] Safer Flow Batteries for Grid Storage http://www.ecnmag.com/news/2015/09/rechargeable-battery-power-home-rooftop-solar-panels A Rechargeable Battery To Power A Home From Rooftop Solar Panels Thu, 09/24/2015 - 2:19pm A team of Harvard scientists and engineers has demonstrated a rechargeable battery that could make storage of electricity from intermittent energy sources like solar and wind safe and cost-effective for both residential and commercial use. The new research builds on earlier work by members of the same team that could enable cheaper and more reliable electricity storage at the grid level. The mismatch between the availability of intermittent wind or sunshine and the variability of demand is a great obstacle to getting a large fraction of our electricity from renewable sources. This problem could be solved by a cost-effective means of storing large amounts of electrical energy for delivery over the long periods when the wind isn't blowing and the sun isn't shining. In the operation of the battery, electrons are picked up and released by compounds composed of inexpensive, earth-abundant elements (carbon, oxygen, nitrogen, hydrogen, iron and potassium) dissolved in water. The compounds are non-toxic, non-flammable, and widely available, making them safer and cheaper than other battery systems. "This is chemistry I'd be happy to put in my basement," says Michael J. Aziz, Gene and Tracy Sykes Professor of Materials and Energy Technologies at Harvard Paulson School of Engineering and Applied Sciences (SEAS), and project Principal Investigator. "The non-toxicity and cheap, abundant materials placed in water solution mean that it's safe—it can't catch on fire—and that's huge when you're storing large amounts of electrical energy anywhere near people." The research appears in a paper published today in the journal Science. This new battery chemistry was discovered by post-doctoral fellow Michael Marshak and graduate student Kaixiang Lin working together with co-lead author Roy Gordon, Thomas Dudley Cabot Professor of Chemistry and Professor of Materials Science at Harvard. "We combined a common organic dye with an inexpensive food additive to increase our battery voltage by about 50 percent over our previous materials," says Gordon. The findings "deliver the first high-performance, non-flammable, non-toxic, non-corrosive, and low-cost chemicals for flow batteries." Unlike solid-electrode batteries, flow batteries store energy in liquids contained in external tanks, similar to fuel cells. The tanks (which set the energy capacity), as well as the electrochemical conversion hardware through which the fluids are pumped (which sets peak power capacity), can be sized independently. Since the amount of energy that can be stored can be arbitrarily increased by scaling up only the size of the tanks, larger amounts of energy can be stored at lower cost than traditional battery systems. The active components of electrolytes in most flow battery designs have been metal ions such as vanadium dissolved in acid. The metals can be expensive, corrosive, tricky to handle, and kinetically sluggish, leading to inefficiencies. Last year, Aziz and his Harvard colleagues demonstrated a flow battery that replaced metals with organic (carbon-based) molecules called quinones, which are abundant, naturally occurring chemicals that are integral to biological processes like photosynthesis and cellular respiration. While quinones in aqueous solution formed the negative electrolyte side of the battery, the positive side relied on a conventional bromine-bearing electrolyte that is used in several other batteries. The high performance and low cost of the technology, which Harvard has licensed to a company in Europe, hold the potential to provide scalable grid-level storage solutions to utilities. But bromine's toxicity and volatility make it most suitable for settings where trained professionals can deal with it safely behind secure fences. So the team began searching for a new recipe that would provide comparable storage advantages—inexpensive, long lasting, efficient—using chemicals that could be safely deployed in homes and businesses. Their new battery, described in a paper published today in the journal Science, replaces bromine with a non-toxic and non-corrosive ion called ferrocyanide. "It sounds bad because it has the word 'cyanide' in it," explains co-lead author Marshak, who is now assistant professor of chemistry at the University of Colorado Boulder. &
