Multiscale Modeling and Rational Design of Novel Electrode Materials of New Cathodes for Li-ion Batteries
EMSL Project ID
49127
Abstract
The present proposal is for computational resources to support a DOE-funded joint experimental and computational project to design and synthesize new materials with high capacities for electrical charge storage; the new materials are being used as cathodes in lithium-ion batteries. We are examining electrochemical lithiation/delithiation of compositionally flexible structures, in particular the highly lithiated, intercalation-type layered compound Li8MO6 and their doped analogs. Doping provides a large number of opportunities for for new materials while keeping the structure of the material essentially unchanged. This allows one to tune critical properties of the material, including electronic band structure, potentials for ion insertion/deinsertion, ion diffusion properties, electronic conductivities, structural and phase stability, and chemical/electrochemical stability in reactive environments. Research during the prior project period demonstrated the viability of the layered platform for electrical energy storage, with a nanocomposite of Y-doped Li8ZrO6/C showing an initial specific capacity exceeding that of current mainstream cathode materials. However, much greater charge storage capacities and faster kinetics are expected if the material composition can be tuned and particle size decreased to increase conductivity, decrease polarization, and stabilize the structure to permit extraction of more than two of the eight Li ions per formula unit. The experimental part of this project is developing synthetic methods to introduce transition metal dopants into specific structural sites to achieve such properties, and the computational part is quantum mechanically characterizing the structural and electrochemical properties of the materials. Materials selection and the prediction and correlation of properties will be guided by theory and quantum mechanical computation, which has already proved to be a successful merger of theory and experiment in the this project. In particular, insight from quantum mechanical calculations has proved to be particularly helpful in selecting dopants that can enhance electron and ion transport in these lamellar structures. Dopants that appear promising from a theoretical point of view are currently being implemented and will also be evaluated further in the continuation project. Electronic structure energy calculations carried out by density functional theory will be used to examine the structural and energetic effects of nanostructural morphology, doping, and size changes and to help understand the mechanism of lithium storage in terms of the geometries and strengths of various binding sites. A new database of reference data will be prepared, and new density functionals will be optimized with reaction parameters specifically designed for electrical energy storage materials.
The computationally guided materials design in this fundamental research is expected to advance electrical charge storage technologies that are needed to take advantage of the rapid progress in electronic device miniaturization, transportation technology, and electrical energy generation. Although successful battery design must ultimately consider the cathode, the anode, and the electrolyte, in lithium-ion batteries the cathode is the major determinant of energy storage capability, maximum speed of energy extraction, thermal stability, cycle life, cost, toxicity, environmental friendliness, and safety. The Li8MO6-based platform, with appropriate substitution of transition metals, is particularly promising to achieve high capacities at high voltages with relatively low-cost/low-toxicity materials.
Project Details
Start Date
2015-10-07
End Date
2016-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Huang S, BE Wilson, B` Wang, Y Fang, K Buffington, A Stein, and DG Truhlar. 2015. "Y?doped Li?ZrO?: A Li-Ion Battery Cathode Material with High Capacity." Journal of the American Chemical Society 137(34):10992–11003. doi:10.1021/jacs.5b04690
Huang S ,Wilson B E,Smyrl W H,Truhlar D G,Stein A 2016. "Transition-Metal-Doped M?Li8ZrO6 (M = Mn, Fe, Co, Ni, Cu, Ce) as High-Specific-Capacity Li-Ion Battery Cathode Materials: Synthesis, Electrochemistry, and Quantum Mechanical Characterization" Chemistry of Materials 28(3):746–755. 10.1021/acs.chemmater.5b03554
Huang S., Y. Fang, B.`. Wang, B.E. Wilson, N. Tran, D.G. Truhlar, and A. Stein. 2016. "Conduction and Surface Effects in Cathode Materials: Li8ZrO6 and Doped Li8ZrO6." Journal of Physical Chemistry C 120. doi:10.1021/acs.jpcc.6b02077
Tang B ,Huang S ,Fang Y ,Hu J ,Malonzo C ,Truhlar D G,Stein A 2016. "Mechanism of Electrochemical Lithiation of a Metal-organic Framework without Redoxactive Nodes" Journal of Chemical Physics 144(19):. 10.1063/1.4948706