"It has become increasingly clear that in order for renewable energy to become the main part, if not all, of our electricity generation system, it needs to match the output of the demand that we have as a society," says senior author Yet-Ming Chiang of MIT's Department of Materials Science and Engineering. "We think that this work helps move us in the right direction and creates more hope that this is possible, but we need to push it ahead very quickly because we don't have a lot of time."
One of the criticisms of renewable energy is its variability. For example, there are times when a cloud goes in front of the sun or when the wind dies down, and so being able to store energy for those down times is essential for uninterrupted energy flow. At the moment, the coupling of energy storage to renewable generation is in its infancy -- it does happen, but of the total amount of solar and wind energy generated, a very small percentage is actually stored, with the cost of energy storage being one of the greatest barriers.
Under the former Secretary of Energy Steven Chu, the Department of Energy's Joint Center for Energy Storage Research set a goal for "5-5-5" (meaning 5 times reduction in cost, 5 times increase in energy density, accomplished in 5 years) for grid storage. In response, Chiang's group focused on the first part of the problem, examining how to create a storage unit with a low cost-per-stored-energy metric (US dollars per kilowatt hour, $/kWh), based on the cost of the cathode, anode, and electrolytes of a battery. Current chemical costs often hover between $10 and $100/kWh as battery materials often need to be mined and shipped from around the globe.advertisement
Source : https://www.sciencedaily.com/releases/2017/10/171011123826.htm