Hello,
A new project on the LCRC cluster has been requested. Please forward
the information on to the LCRC Allocation sub-committee.
Applicant's name: Anh Ngo
Applicant's institution: ANL
Applicant's division: MSD
Project Name: SEI
Project title: The effect of the transition metals on the solid electrolyte interphase in Li-ion batteries
Associated funding: LDRD
Other Systems:
Science: Li-ion batteries (LIB) have become one of the most advanced rechargeable batteries as they shown great promise as power sources that can lead to the next electric vehicle revolution. Currently, rechargeable Li-ion batteries are key components of the mobile power sources for portable electronic devices. With high energy efficiency, Li-ion batteries may also be used in various electric applications including energy storage for renewable energy sources from wind and solar , however its large-scale applications are still hampered by narrow working temperature ranges and safety concerns under.
For Li-ion batteries with cathode materials such as the layered LiMO2 where M is a transition metal (M = Mn, Co, Ni), M(II) ions are dissolved from the cathode and transferred by diffusion and migration toward the opposite anode through the thin separator. The experimental observation of the charge – discharge curves at the graphite electrode indicate that M(II) deposition causes a large reduction in the reversible capacity of the graphite anode which becomes worse with increasing M(II) concentration. The actual mechanism by which transition metal dissolution affects the solid electrolyte interphase (SEI) growth on the anode is still unclear and remains puzzling.
In this study, we plan to address in detail several reactions of M(II) ions with major products of the SEI including lithium carbonate (Li2CO3), lithium fluoride (LiF), and lithium oxide (Li2O). The project will be carried out in as part of the CEES-II EFRC (Argonne) by theorists Anh Ngo (MSD), Hakim Iddir (MSD), and Larry Curtiss (MSD), who specialize in Density Functional Theory calculations.
We will focus on following questions:
1. What is the impact of an M ion and its doping concentration on SEI structures?
2. What are oxidation/charge states of M ions in SEI structures?
3. Which mechanism causes capacity fading in Li ion batteries in the transition metal cathode materials?
Such study will provide valuable information and we will be able to validate our theoretical results with the ongoing experimental efforts at Argonne.
Project description: Description:
Structure optimizations of Li2CO3, LiF and Li2O (~100 atoms) with different magnetic configurations will be carried out using (2 x 2x 2) bulk unit cells. By comparing different magnetic ordering energies we will conclude which configuration corresponding to the ground state energy.
Once the ground state structure is found we will go on to address the SEI structural dependence of M ion doping concentration. We intend to carry out the density functional theory (DFT) calculations using the VASP package and the GPAW code. Periodic boundary conditions (PBC) will be imposed in order to maintain periodicity of the solid support. The gradient corrected PBE density functional will be used for these calculations. Those programs are currently available on Blues cluster and scale reasonably well on parallel processors.
Since SEI doped M is a correlated complex oxide, we will perform density functional theory (DFT) calculations using the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional and perform the atomic relaxations within the unit cells. Energy optimization of the SEI structure (~100 atoms) using HSE takes approximately 9216 CPU hours (16*6*96) and we plan roughly 55 such calculations.
For doping calculations, each takes approximately 6912 CPU hours (16*6*72) and we plan to run 68 of these calculations. So our total request is 9216*55 + 16*6*72 *68 = 976896 core hours.
Industry partnership:
Project URL:
Requested allocation: 976896
Q1: 76896
Q2: 300000
Q3: 300000
Q4: 300000
Justification: VASP performance on Blues is well established, we use the latest version maintained on Blues.
Storage requirements: 1 TB is sufficient
The requester has used undetermined amount hours of their initial startup project.
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The LCRC Accounts System
