Robert A. Huggins
Department of Materials Science and Engineering
One of the major problems related to the integration of renewable energy sources with the large scale electric distribution grid has to do with the high frequency of short-term transients. The amelioration of this problem requires energy storage systems that can operate at very high rates, and with a high efficiency over a very large number of cycles.
The structural features that lead to the exceptional performance of a new group of insertion reaction electrode materials in aqueous electrolyte electrochemical systems for this purpose will be described.
Experiments have already demonstrated the outstanding properties of some members of this family. In one case, over 40,000 full cycles have already been achieved at a very high (17C) rate, with a coulomb efficiency of 99.8%. In another, over 5,000 full cycles at an 8.3 C rate have shown no measurable decrease in capacity.