Battery Power - Spring 2014 - (Page 28)

Research & Development Organic Mega Flow Battery Promises Breakthrough for Renewable Energy A team of Harvard scientists and engineers has demonstrated a new type of battery that could fundamentally transform the way electricity is stored on the grid, making power from renewable energy sources such as wind and solar far more economical and reliable. Under the OPEN 2012 program, the Harvard team received funding from the US Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E) to develop the innovative grid-scale battery and plans to work with ARPA-E to catalyze further technological and market breakthroughs over the next several years. A new paper reports a metal-free flow battery that relies on the electrochemistry of naturally abundant, inexpensive, small organic (carbon-based) molecules called Michael J. Aziz (pictured) and others at Harvard University have developed a metal-free quinones, which are similar to molecules flow battery that relies on the electrochemistry of naturally abundant, small organic molthat store energy in plants and animals. ecules to store electricity generated from renewable, intermittent energy sources. (Photo The mismatch between the availability by Eliza Grinnell, SEAS Communications.) of intermittent wind or sunshine and the "Our studies indicate that one to two days' worth of storage variability of demand is the biggest obstacle is required for making solar and wind dispatchable through the to getting a large fraction of our electricity from renewable electrical grid," said Aziz. sources. A cost-effective means of storing large amounts of To store 50 hours of energy from a 1-megawatt power capacelectrical energy could solve this problem. ity wind turbine (50 megawatt-hours), for example, a possible The battery was designed, built, and tested in the laboratory of Michael J. Aziz, Gene and Tracy Sykes Professor of Materials solution would be to buy traditional batteries with 50 megawatthours of energy storage, but they'd come with 50 megawatts and Energy Technologies at the Harvard School of Engineerof power capacity. Paying for 50 megawatts of power capacity ing and Applied Sciences (SEAS). Roy G. Gordon, Thomas Dudley Cabot Professor of Chemistry and Professor of Materials when only 1 megawatt is necessary makes little economic sense. For this reason, a growing number of engineers have focused Science, led the work on the synthesis and chemical screening their attention on flow battery technology. But until now, flow of molecules. Alán Aspuru-Guzik, Professor of Chemistry and Chemical Biology, used his pioneering high-throughput molecu- batteries have relied on chemicals that are expensive or difficult to maintain, driving up the energy storage costs. lar screening methods to calculate the properties of more than The active components of electrolytes in most flow batteries 10,000 quinone molecules in search of the best candidates for have been metals. Vanadium is used in the most commercially the battery. advanced flow battery technology now in development, but its Flow batteries store energy in chemical fluids contained in cost sets a rather high floor on the cost per kilowatt-hour at any external tanks, as with fuel cells, instead of within the battery scale. Other flow batteries contain precious metal electrocatacontainer itself. The two main components, the electrochemical lysts such as the platinum used in fuel cells. conversion hardware through which the fluids are flowed and The new flow battery developed by the Harvard team sets the peak power capacity, and the chemical storage tanks that already performs as well as vanadium flow batteries, with set the energy capacity, may be independently sized. Thus the chemicals that are significantly less expensive, and with no amount of energy that can be stored is limited only by the size precious metal electrocatalyst. of the tanks. The design permits larger amounts of energy to be "The whole world of electricity storage has been using metal stored at lower cost than with traditional batteries. ions in various charge states but there is a limited number that By contrast, in solid-electrode batteries, such as those comyou can put into solution and use to store energy, and none of monly found in cars and mobile devices, the power conversion them can economically store massive amounts of renewable hardware and energy capacity are packaged together in one unit energy," Gordon said. "With organic molecules, we introduce a and cannot be decoupled. Consequently they can maintain peak vast new set of possibilities. Some of them will be terrible and discharge power for less than an hour before being drained, and some will be really good. With these quinones we have the first are therefore ill suited to store intermittent renewables. 28 Battery Power * Spring 2014 www.BatteryPowerOnline.com http://www.BatteryPowerOnline.com

Table of Contents for the Digital Edition of Battery Power - Spring 2014

NREL Model Licensed to Improve Accuracy of Battery Simulations
Companies Collaborate to Make Wireless Power As Commonplace as WiFi
Improving the Coulombic Efficiency and Lifetime Of Li-Ion Cells Demands High Precision, High Accuracy Testing
Rapid Charging for Battery-Powered Portable Devices
Managing Fleet Batteries and Knowing When to Retire Them
Batteries
ICs & Semiconductors
Charging Systems
Industry News
Research & Development
Marketplace

Battery Power - Spring 2014