[4/9] AIMR Special Seminar
AIMR asks Dr. Ziheng Lu, the postdoctoral research associate of Materials Theory Group, Department of Materials Science & Metallurgy, University of Cambridge where Prof. Chris J. Pickard (Principal Investigator of AIMR) has his main position in Cambridge, to give a talk about the recent results of the theoretical study aiming to design new cathode materials suitable for lithium-ion batteries based on ab initio random structure searching (AIRSS). Although this presentation will be given as a special event during AIMR's Friday Tea Time, you can continue the discussion with the speaker after the end of the Tea Time.
Dr. Ziheng Lu
(Materials Theory Group, Department of Materials Science & Metallurgy, University of Cambridge)
Ab initio random structure searching for battery cathodes and more
April 9 (Fri.), 2021 16:00-16:40 on Japan Time (8:00-8:40 on British Summer Time)
Although we temporarily close this seminar as a special event of AIMR's Friday Tea Time at around 16:40, the participants who wish to hear more details can continue Zoom connection and the discussion with Dr. Lu till around 17:30.
Cathodes are critical components of rechargeable batteries. Conventionally, the search for cathode materials relies on experimental trial-and-error and a traversing of existing computational/experimental databases. While these methods have led to the discovery of several commercially-viable cathode materials, the chemical space explored so far is limited and many phases will have been overlooked, in particular those that are metastable. We describe a computational framework for battery cathode exploration, based on ab initio random structure searching (AIRSS), an approach that samples local minima on the potential energy surface to identify new crystal structures. We show that, by delimiting the search space using a number of constraints, including chemically aware minimum interatomic separations, cell volumes, and space group symmetries, AIRSS can efficiently predict both thermodynamically stable and metastable cathode materials.
Specifically, we investigate LiCoO2, LiFePO4, and LixCuyFz to demonstrate the efficiency of the method by rediscovering the known crystal structures of these cathode materials. The effect of parameters, such as minimum separations and symmetries, on the efficiency of the sampling is discussed in detail. The adaptation of the minimum interatomic distances, on a species-pair basis, from low-energy optimized structures to efficiently capture the local coordination environment of atoms, is explored. A family of novel cathode materials based, on the transition-metal oxalates, is proposed. They are predicted to demonstrate superb energy density, oxygen-redox stability, and lithium diffusion properties.
The application of AIRSS and density functional theory-based thermodynamics to solid electrolytes and interfaces will also be briefly talked about.
Regarding AIMR's Tea Time
International Affairs Center (IAC), AIMR
|Address:||2-1-1, Katahira, Aoba-ku, Sendai, 980-8577|
Regarding the talk
Susumu Ikeda, AIMR Research Support Division