金属离子与碳基材料相互作用机制及相应电极材料设计

At present, the relative low abundance of Li has become an important factor restricting the large-scale application of lithium ion batteries. It is imperative to develop novel metal ion batteries based on the more abundant elements on earth to replace lithium ion batteries. However, the present unsatisfactory performances of Na, K ion batteries, etc., cannot guarantee practical applications, and the development of electrode materials with low cost and excellent performance is the main challenge for metal ion batteries. It is urgently necessary to deeply explore some fundamental scientific problems in this field, such as the interaction between metal ions and material substrates. In this proposal, we would clarify the effect of microstructures of materials upon the storage capability of various metal ions by theoretical computations, and study the kinetic processes of the intercalation and diffusion of metal ions by molecular dynamics simulations, so as to understand the microscopic storage mechanism, disclose thoroughly the abnormal intercalation of Na and Mg in graphite, and summarize the deep rules of the interaction between metal ions and material substrates. With the guidance of theoretical computations, we could further design and prepare electrode materials for metal ion batteries via chemical routes, and detect the structural evolution of electrode materials during electrochemical reactions through in situ measurements. With repeated verification between computations and experiments, we would propose design principles for corresponding electrode materials of metal ion batteries and direct the development of carbon-based electrode materials.

目前，锂资源短缺已成为制约锂离子电池大规模应用的重要因素，利用地球储量更丰富的元素发展廉价高效的可替代锂离子电池的新型金属离子储能体系势在必行。目前钠和钾等金属离子电池的性能距离实际应用还有很大的差距，开发价格低廉、性能优异的电极材料是金属离子电池所面临的主要挑战，急需深入研究金属离子与材料基体的相互作用机制等基础科学问题。本申请通过理论计算揭示材料微观结构对不同金属离子的存储能力的影响，通过分子动力学模拟研究金属离子的嵌入和扩散的动力学过程，理解相应的微观存储机理，全面揭示钠和镁在石墨中的异常嵌入行为，总结金属离子与材料基体相互作用机制的深层次规律。在理论计算结果的指导下，通过可行的化学方法设计制备金属离子电池电极材料，采用原位测试手段研究电极材料在电化学反应过程中的结构演化，通过计算模拟与实验紧密结合反复验证，提出相应金属离子电池电极材料设计原理，为高性能碳基电极材料的研发指明方向。

本项目主要通过实验与理论计算相结合的方式研究金属离子与碳基复合材料的作用机制，研发具有优良电化学性能的电极材料和新型储能体系。基于对碳基复合材料储钠机制的深刻认识，通过微纳米结构调控制备了具有优良电化学性能的钠离子电池负极材料和石墨烯改性的高电压正极材料，组装了具有优异电化学性能的钠离子全电池和钠离子电容器。提出一种简单有效的基于Materials Project材料数据库搜索层状二维材料的方法，能够快速筛选适用于不同类型金属离子储能体系的电极材料。已发表研究论文10篇和综述3篇，论文发表后被SCI引用580余次，1篇论文进入ESI近10年高被引论文。