• Low-cost and High-Energy Cathode Materials for Next-Generation Li-ion Batteries.

Li-ion batteries (LIBs) have become an integral part of the modern society. It powers various modern electronic devices such as our laptop computers, mobile phones, etc. Inspired by its successful implementation for ‘small’ electronic devices, academia and industries are now intensively trying to widen LIBs usage into electric vehicle (EV) and grid storage applications. Thus, the need of LIBs with higher energy density, longer life cycle, safer and lower price is of utmost importance.

Out of three key components of LIBs (i.e. anode, cathode, electrolyte), cathode often becomes the performance-limiting factor. This is due to multiple degradations that cathode possibly suffer over repeated charging/discharging cycles (e.g. irreversible phase transformation, cathode-electrolyte interface (cSEI) formations, particle cracking, etc.). Those phenomena may lead to LIBs cell failure such as thermal runway and rapid performance fading. Hence, rationale design of cathode materials that can withstand the aforementioned failures is important.

By means of state-of-the-art first-principles Density Functional Theory and Molecular Dynamics simulation, our research objectives are two folds: 1) understanding the fundamental origins of LIBs failure mainly caused by the degradation of cathode and 2) performance improvement of potential high-energy cathode compounds (i.e. layered Ni-rich oxides, Li-rich oxides, etc.). This will be done in terms of understanding the followings: oxygen evolution mechanism, electrolyte-cathode interaction and phase transformation mechanism in LIBs cathode. The knowledge gained will be used as a guideline to design high-energy cathode with more robust structure.

References:

  1. Okuno, Y., Ushirogata, K., Sodeyama, K., Shukri, G., Tateyama, Y. Structures, Electronic States, and Reactions at Interfaces between LiNi5Mn1.5O4 Cathode and Ethylene Carbonate Electrolyte: A First-Principles Study. J. Phys. Chem. C. 123, 2019, 2267-2277.
  2. Manthiram, A., Song, B., Li, W. A Perspective on Nickel-rich Layered Oxide Cathodes for Lithium-ion Batteries. Energy Storage Materials 6, 2017, 125-139.

 

  • Physics and Chemistry of Defects in Semiconductors