高通量筛选加速新一代电池的开发

由于锂的成本高昂并且资源不足，钠离子电池因而得到了广泛研究以便大规模应用。就电极材料来说，插入型材料比合金型和转换型材料通常拥有更好的循环稳定性。然而Na+的离子半径比Li+的离子半径大55％，这就要求主体骨架具有更大的空间用于Na+的储存和输运，因而迫切需要寻找合格的Na+宿主材料。来自中国南开大学的周震教授等，开发了一种快速的“高通量”计算方法，以搜索大量在线“材料项目”数据库中的层状钠基材料。他们通过计算所获得的Na基层状材料包含38种空间群，表明该筛选方法的可信度不受空间群影响。作者通过密度泛函理论计算，进一步研究了这些材料的储能代表性指标，如平均电位、体积变化和钠离子迁移率等，评估了候选材料在钠离子电池中的潜在应用。发现数据库中的一些材料，包括Na(CuO)2、NaTiF4、Na2Zr(CuS2)2、Na3Co2SbO6和Na2Cu(CO3)2，体积变化和钠扩散能垒均很低，可能适合用作'嵌入式'正极材料。作者希望此法也可以用于搜索其他基于碱金属离子和多价离子的层状材料作为潜在电极，并希望以此加速新一代电池的开发。该文近期发表于npj Computational Materials 4:13(2018); doi:10.1038/s41524-018-0070-2。英文标题与摘要如下，点击阅读原文可以自由获取论文PDF。

An effective method to screen sodium-based layered materials for sodium ion batteries

Xu Zhang,Zihe Zhang,Sai Yao,An Chen,Xudong Zhao&Zhen Zhou

Due to the high cost and in sufficient resource of lithium, sodium-ion batteries are widely investigated for large-scale applications. Typically, insertion - type materials possess better cyclic stability than alloy - type and conversion-type ones. Therefore, in this work, we proposed a facile and effective method to screen sodium-based layered materials based on Materials Project database as potential candidate insertion-type materials for sodium ion batteries. The obtained Na-based layered materials contains 38 kinds of space group, which reveals that the credibility of our screening approach would not be affected by the space group. Then, some important indexes of the representative materials, including the average voltage, volume change and sodium ion mobility, were further studied by means of density functional theory computations. Some materials with extremely low volume changes and Na diffusion barriers are promising candidates for sodium ion batteries. We believe that our classification algorithm could also be used to search for other alkali and multivalent ion-based layered materials, to accelerate the development of battery materials.