基于碳族元素的新型二维材料在非液态锂-氧电池阴极上催化活性的理论计算研究

Due to the extremely high theoretical energy density, lithium-oxygen (Li-O2) batteries have received extensive attentions. The catalytic activity of cathode catalysts is the main limiting factor to the development of Li-O2 batteries, so it is of great importance to develop highly active metal-free catalytic materials to replace the noble metal catalysts. For metal-free materials, which key factors affect their catalytic activity as cathode catalysts in nonaqueous Li-O2 batteries, and what quantitative relationship may exist is still unknown. The preliminary investigations have found that the novel two-dimensional materials based carbon-group elements not only have excellent adsorption and dissociation activity for oxygen, but also show similar regulations with Pt-based catalysts on the adsorption of intermediates. Based on these, this project plans to systematically study the catalytic mechanism and catalytic activity of these two-dimensional materials as cathode catalysts in nonaqueous Li-O2 batteries, by adopting the well-defined density functional theory calculations. It is expected to innovatively construct the quantitative correlations between the catalytic activity of metal-free two-dimensional catalysts and the influencing factors, and to unify the oxygen reduction reactions in fuel cells and nonaqueous Li-O2 batteries. The project may provide theoretical basis to the discovery of metal-free nanomaterials that can replace noble metal based catalysts, thus facilitate the improvement of nonaqueous Li-O2 battery technology.

锂-氧（Li-O2）电池以其极高的理论能量密度受到广泛的重视，而阴极催化剂的催化活性是制约其发展的主要因素，因而发展高活性的无金属催化材料用于取代贵金属基催化剂极其必要。对于无金属材料而言，用于非液态Li-O2电池阴极催化时的催化活性主要受哪些关键因素的影响，以及它们之间存在怎样的定量关系目前还不清楚。前期的研究发现基于碳族元素的新型二维材料不仅具备出色的氧气吸附和解离活性，且在中间产物吸附方面与铂基催化剂有着相似的规律。基于此，本项目拟采用成熟的密度泛函理论计算，对此类二维材料用作非液态Li-O2电池阴极催化剂时的催化机理和催化活性进行系统研究，希望能创新性地建立无金属二维材料的催化活性与相关影响因素之间的定量关系式，并将燃料电池和非液态Li-O2电池的氧还原催化相统一，为寻找能够用于取代贵金属基催化剂的无金属纳米材料提供理论依据，从而推动非液态Li-O2电池技术的发展。

本项目采用密度泛函理论计算，对基于碳族元素的新型二维材料用作非液态Li-O2电池阴极催化剂时的催化机理和催化活性进行了系统研究，预测了一系列性能出色的非液态Li-O2电池阴极催化剂（如g-GeC和BC3），并揭示了无金属二维材料的催化活性与其结构和电子性质之间的关联。本项目将燃料电池和非液态Li-O2电池的氧还原催化相统一，为寻找能够用于取代贵金属基催化剂的无金属纳米材料提供了理论依据。