Speaker
Description
Tuning positive electrode materials in lithium-ion cells provides a promising means for lowering cost of materials while maintaining safety and energy density standards. Due to the rising cost of cobalt, it is important to find less expensive alternatives. Here we present results from first-principles computations within the formalism of density functional theory examining changes in electronic properties and thermodynamic stability of Li$_{x}$Ni$_{1-y-z}$Al$_{y}$Co$_{z}$, where $0\lt x \lt 1$ and $0\lt y,z \lt 0.2$, positive electrode materials as a function of cobalt, aluminum, and lithium content. Results using a new exchange-correlation functional (SCAN) [1,2] within the class of meta-GGAs are compared with the traditionally employed empirical GGA+U. Fundamental understanding of these properties may help in designing less expensive positive electrode materials.
[1] Strongly Constrained and Appropriately Normed Semilocal Density Functional, J. Sun, A. Ruzsinszky, and J. P. Perdew, Phys. Rev. Lett. 115, 036402 (2015)
[2] Accurate first-principles structures and energies of diversely bonded systems from an efficient density functional, J. Sun et al., Nature Chemistry 8, 831–836 (2016)
