Solid polymer electrolyte (SPE) rechargeable lithium batteries offer several potential advantages over current battery technologies based on liquid electrolytes. Easy containment of the solid electrolyte allows for more latitude in designing the battery shape, higher energy densities, and reduced environmental hazards. However, these potential advantages have not been fully realized after decades of research due to the low ion conductivity of SPE. Dramatic increases of the Li ion conductivity are needed and this progress requires the understanding of Li conduction mechanism.
PEO is widely studied as the polymer matrix for SPE. The lithium mobility is believed to be coupled with PEO segmental motion as one lithium ion is coordinated by several ether oxygen atoms. Quasielastic neutron scattering (QENS) is a well-suited technique to study the PEO segmental motion. Paring QENS with conductivity measurement by impedance spectroscopy on PEO/lithium salt complex can quantify the coupling of PEO segmental motion and lithium diffusion. The approach can be extended to SPE systems with additives such as nanoparticles and plasticizers, and therefore, the mechanism behind lithium conductivity improvement can be revealed.
Select Non-NIST publications:
Electronics Materials Group
2009 – Present, Guest Researcher, Polymers Division, NIST
2006 – 2008, Postdoctoral Research Associate, California Institute for Telecommunications and Information Technology, University of California, Irvine
2004 – 2006, Postdoctoral Research Associate, Physics Department, University of Michigan, Ann Arbor
Ph.D., Materials Science and Engineering, 2004
University of Michigan,Ann Arbor
Bachelor of Engineering, Chemical Engineering, 1998
Tsinghua University, Beijing, P.R. China