Functional materials and devices are usually morphologically complex and chemically heterogeneous. Their structures are often designed to be hierarchical because of the desired functionalities, which usually require many different components to work together in a coherent manner. The lithium ion battery (LIB), as an energy storage device, is a very typical example of this kind of structure.
Probing the structural and chemical complexity in batteries across a wide range of length and time scales poses a frontier challenge in this field. For example, cathode materials with different lattice structure could behave very differently as they offer different diffusion channels for the charge carriers in the system; the particles, which are regarded as practical building blocks for the battery electrode, could have different responses to the cycling conditions due to the heterogeneous local chemistry; the composite electrode needs to offer sufficient mechanical support as well as balanced conductivity for both charge carriers.
Our group tackles the scientific questions in this field using a systematic approach that involves cutting-edge characterization and scientific computing/modeling tools. In particular, we are interested in understanding the complicated electro-thermo-chemo-mechanical interplay in the battery system, which could be the root cause of the structural and chemical defects that eventually affects the cell level chemistry.
