38

nanotimes News in Brief

adhere tightly to the silicon particles as they acquire or lose lithium ions and undergo repeated changes in volume.

Scanning electron microscopy and transmission elec- tron microscopy at the National Center for Electron Microscopy (NCEM), showing the anodes after 32 charge-discharge cycles, confirmed that the modified polymer adhered strongly throughout the battery operation even as the silicon particles repeatedly expanded and contracted. Tests at the ALS and simu- lations confirmed that the added mechanical proper- ties did not affect the polymer’s superior electrical properties.

“Without the input from our partners at the ALS and in MSD, what can be modified and what should not be modified in the next generation of polymers would not have been obvious,” says Vince Battaglia, Program Manager of EETD’s Advanced Energy Tech- nologies Department.

“This achievement provides a rare scientific show- case, combining advanced tools of synthesis, cha- racterization, and simulation in a novel approach to materials development,” says Zahid Hussain, the ALS Division Deputy for Scientific Support and Scientific Support Group Leader. “The cyclic approach can lead to the discovery of new practical materials with a fundamental understanding of their properties.”

The icing on the anode cake is that the new PF-based anode is not only superior but economical.

“Using commercial silicon particles and without any conductive additive, our composite anode exhibits the best performance so far,” says Gao Liu. “The

11-09 :: September 2011

whole manufacturing process is low cost and compa- tible with established manufacturing technologies.

The commercial value of the polymer has already been recognized by major companies, and its possi- ble applications extend beyond silicon anodes.”

Anodes are a key component of lithium-ion battery technology, but far from the only challenge. Alrea- dy the research collaboration is pushing to the next step, studying other battery components including cathodes.

Gao Liu, Shidi Xun, Nenad Vukmirovic, Xiangyun Song, Paul Olalde-Velasco, Honghe Zheng, Vince S. Battaglia, Lin-Wang Wang, and Wanli Yang: Polymers with Tailo- red Electronic Structure for High Capacity Lithium Battery Electrodes, In: Advanced Materials AOP, DOI:10.1002/ adma.201102421:

-

http://dx.doi.org/10.1002/adma.201102421 http://batt.lbl.gov/ http://www-als.lbl.gov/ http://ncem.lbl.gov/