A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage

• Published in: Nature communications 2012-10, Vol.3 (1), p.1149-1149, Article 1149
• Main Authors: Pasta, Mauro, Wessells, Colin D., Huggins, Robert A., Cui, Yi
• Format: Article
• Language: English
• Subjects: 639/301/299/161/891; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms2139

New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles. The integration of volatile renewable energy sources into the electrical power grid will require a significant increase in electrical storage capacity. Here a new type of safe, fast, inexpensive and long-life aqueous electrolyte battery is reported, which may aid the development of increased grid capacity.