过渡金属层状高熵氧化物的形成机制、储钾性能及机理研究

高熵氧化物（HEO）是一种阳离子无序排列的新型多组分化合物，具有高稳定性、超高离子电导率等优点，在储能领域应用潜力巨大。本项目提出利用高熵结构设计钾离子电池正极材料，拟以层状结构高熵氧化物为研究目标，围绕其形成机制、储钾性能及机理展开研究。通过理论计算预测过渡金属HEO的相结构和稳定性；采用高温固相法合成一系列HEO，利用变温XRD原位追踪其结构演变过程，系统探究单一元素的影响，揭示HEO的形成机制，获取成分设计原则及结构调控途径；系统研究HEO在钾离子半电池及全电池中的电化学性能，探究HEO的组成及合成条件对储钾性能的影响规律，探明关键影响因素及性能调控途径；利用原位XRD和三维重构等技术揭示HEO充放电过程中结构、成分演变规律，结合理论计算构建模型并揭示其储钾机理。该研究成果有望获得高性能的储钾正极材料，为新型高熵材料的科学设计、高效制备及在储能领域的应用提供理论指导和技术途径。

High entropy oxide (HEO) is a new multicomponent complex with disordered cationic array and it exhibits high structure stability and superhigh ionic conductivity, which make it great application potential in energy storage filed. This project proposes to use high entropy structure to design cathode materials for potassium ion batteries, we focus on the potassium-ion storage properties of HEO with layered structure, and we plan to investigate the composition design and formation mechanism of the layered high entropy oxide and figure out the potassium storage mechanism of HEO. Specifically, first, we decide to predict the phase structure and the stability of transition metal HEO by the first principle calculation. Furthermore, we will fabricate a series of HEOs by high temperature solid phase method and investigate the structure evolution mechanism via in-situ variable temperature XRD technology. Moreover, we will change the composition of HEO and investigate the effect of single element to the formation of HEO, and finally obtain the formation mechanism of HEO as well as structure adjustment and control approaches. Second, we will systemically measure the potassium-ion storage performances of HEOs by both half-cells and full-cells, study the effects of composition and fabrication conditions on the electrochemical performances of HEO, and ascertain the key influence factors for performance regulation. Third, we will combine various in-situ technologies with theoretical calculation to reveal the structure evolution of HEO during the charge/discharge process and build a model to ascertain the storage mechanism of HEO. As a result, it is hopeful to acquire a kind of high-performance cathode material for potassium ion batteries. Moreover, these results will be able to provide theoretical guidance and technical approach for scientific design, efficient fabrication, and the application of HEO in energy storage field.