Thermodynamics of multi-sublattice battery active materials: from an extended regular solution theory to a phase-field model of LiMn_(y)Fe_(1-y)PO_(4)  

作　　者：Pierfrancesco Ombrini Martin Z.Bazant Marnix Wagemaker Alexandros Vasileiadis 

机构地区：[1]Storage of Electrochemical Energy,Department of Radiation Science and Technology,Faculty of Applied Sciences,Delft University of Technology,Mekelweg 15,2929JB Delft,The Netherlands [2]Department of Chemical Engineering Massachusetts Institute of Technology,Cambridge,MA 02139,USA [3]Department of Mathematics,Massachusetts Institute of Technology,Cambridge,MA 02139,USA

出　　处：《npj Computational Materials》2023年第1期792-802,共11页计算材料学（英文）

摘　　要：Phase separation during the lithiation of redox-active materials is a critical factor affecting battery performance,including energy density,charging rates,and cycle life.Accurate physical descriptions of these materials are necessary for understanding underlying lithiation mechanisms,performance limitations,and optimizing energy storage devices.This work presents an extended regular solution model that captures mutual interactions between sublattices of multi-sublattice battery materials,typically synthesized by metal substitution.We apply the model to phospho-olivine materials and demonstrate its quantitative accuracy in predicting the composition-dependent redox shift of the plateaus of LiMn_(y)Fe_(1-y)PO_(4)(LFMP),LiCo_(y)Fe_(1-y)PO_(4)(LFCP),LiCo_(x)Mn_(y)Fe_(1-y)PO_(4)(LFMCP),as well as their phase separation behavior.Furthermore,we develop a phase-field model of LFMP that consistently matches experimental data and identifies LiMn0.4Fe0.6PO4 as a superior composition that favors a solid solution phase transition,making it ideal for high-power applications.

关 键 词：BATTERY phase separation 

分 类 号：TB3[一般工业技术—材料科学与工程]