高通量篩選加速新一代電池的開發(fā)

由于鋰的成本高昂并且資源不足，鈉離子電池因而得到了廣泛研究以便大規(guī)模應用。就電極材料來說，插入型材料比合金型和轉換型材料通常擁有更好的循環(huán)穩(wěn)定性。然而Na+的離子半徑比Li+的離子半徑大55％，這就要求主體骨架具有更大的空間用于Na+的儲存和輸運，因而迫切需要尋找合格的Na+宿主材料。來自中國南開大學的周震教授等，開發(fā)了一種快速的“高通量”計算方法，以搜索大量在線“材料項目”數(shù)據(jù)庫中的層狀鈉基材料。他們通過計算所獲得的Na基層狀材料包含38種空間群，表明該篩選方法的可信度不受空間群影響。作者通過密度泛函理論計算，進一步研究了這些材料的儲能代表性指標，如平均電位、體積變化和鈉離子遷移率等，評估了候選材料在鈉離子電池中的潛在應用。發(fā)現(xiàn)數(shù)據(jù)庫中的一些材料，包括Na(CuO)2、NaTiF4、Na2Zr(CuS2)2、Na3Co2SbO6和Na2Cu(CO3)2，體積變化和鈉擴散能壘均很低，可能適合用作'嵌入式'正極材料。作者希望此法也可以用于搜索其他基于堿金屬離子和多價離子的層狀材料作為潛在電極，并希望以此加速新一代電池的開發(fā)。該文近期發(fā)表于npj Computational Materials 4:13(2018); doi:10.1038/s41524-018-0070-2。英文標題與摘要如下，點擊閱讀原文可以自由獲取論文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.