The search for new materials that could improve the energy density of Li-ion batteries (LIB) is one of today's most challenging issues. Recently, cation-disordered lithium-excess metal oxides have emerged as a promising new class of cathode materials for LIB, due to their high reversible capacities and nice structural stability. However, a full structural model of the Li-transition metal (TM) sharing sublattice and the origin of short range ordering (SRO) of cations requires further investigation. In this work, we put forward a Monte Carlo strategy of building cation-disordered rocksalt material supercell models. The cations of Li_1.0Ti_0.5Ni_0.5O₂ (LTNO) are placed at the FCC sublattice sites with the constraint of Pauling's electroneutrality rule, instead of a random way. This constraint causes the Li-Ti and Ni-Ni clustering. Based on this model, we discussed the relationship between the SRO, the local distorting, the theoretical capacity and the order-disorder strengths. A unified understanding of these factors in cation-disordered materials may enable a better design of disordered-electrode materials with high capacity and high energy density.

寻找可以提高锂离子电池（LIB）能量密度的新材料是当今最具挑战性的问题之一。最近，由于无序的锂过量金属氧化物具有高的可逆容量和良好的结构稳定性，它们已成为有前途的新型LIB阴极材料。但是，共享亚晶格的锂过渡金属（TM）的完整结构模型以及阳离子的短程有序（SRO）的起源需要进一步研究。在这项工作中，我们提出了建立阳离子无序岩石盐材料超细胞模型的蒙特卡洛策略。Li _1.0 Ti _0.5 Ni _0.5 O ₂的阳离子（LTNO）置于鲍林电中性规则的约束下，而不是随机地置于FCC子晶格位置。该约束导致Li-Ti和Ni-Ni聚集。在此模型的基础上，我们讨论了SRO，局部失真，理论能力和有序无序强度之间的关系。对阳离子无序材料中这些因素的统一理解可以更好地设计具有高容量和高能量密度的无序电极材料。