Peichen Zhong1,2,Fengyu Xie1,2,Gerbrand Ceder1,2
University of California, Berkeley1,Lawrence Berkeley National Laboratory2
Peichen Zhong1,2,Fengyu Xie1,2,Gerbrand Ceder1,2
University of California, Berkeley1,Lawrence Berkeley National Laboratory2
Disordered rocksalt materials are the most promising earth-abundant cathode materials for Li-ion batteries, and as such can enable scaling of Li-ion energy storage to many TWh/year production. Such modern battery materials can contain a large number of elements with substantial site disorder, and their state of short-range ordering has been shown to be critical for their performance. Ab-initio modeling of the configurational degrees of freedom increases exponentially with the number of species included. The problems to apply cluster expansion techniques include: (1) how to generate lattice models without over-fitting; (2) how to properly sample the configurational space in ionic systems with charge-neutrality.<br/><br/>To address these, we will demonstrate two novel methods to approach the multi-component space of DRX: (1) applying L0L2-norm regularized regression with structural hierarchy to construct a robust cluster expansion Hamiltonian. (2) implementing grand-canonical Monte Carlo to sample charge-balanced ionic configurations. We apply these approaches to compute the voltage profile of Li<sub>1.3-x</sub>Mn<sub>0.4</sub>Nb<sub>0.3</sub>O<sub>1.6</sub>F<sub>0.4</sub>, and demonstrate how Mn and oxygen contributes to the redox potential as Li is intercalated.