TEM-EELS studies of electrode materials for Li-ion batteries


Feng Wang

Sustainable Energy Technologies Department

Brookhaven National Laboratory

Upton NY 11973


            Lithium ion batteries have become the most popular rechargeable storage devices for portable electronics, and are being intensively investigated for potential use in electrical vehicles and grid storage. Developing new materials for these demanding applications requires a better understanding of how electrode materials function by tracking electrochemical reactions in the electrodes. However, this type of characterization requires high sensitivity to Li and other constituents at relevant spatial and temporal resolution, along with the capability of capturing changes in both electronic and atomic structures. We developed a suite of electron microscopy (TEM-EELS) for determination of physical and chemical changes of high-energy electrodes. The versatility of the new approaches to track the electrochemical reaction in nanoelectrodes will be discussed along with our recent results on a variety of nanoparticle-based systems including conversion electrodes (FeF2), alloying electrodes (Si) and intercalation electrodes (Li4Ti5O12).


            This work was supported by the Northeastern Center for Chemical Energy Storage, an Energy Frontier Research Center funded by the U.S. DOE, BES under award No. DE-SC0001294, and BNL-LDRD under contract DE-AC02-98CH10886.