Fundamental Studies on Lithium -Ion Batteries with High Specific Energy Density

本项目将结合实验和理论方法，研究新一代高容量锂离子电池正极材料Li2(M1/M2)O3 （M1、M2 = Mn、Ru、Ni、Co等）及其配套电解质，构建和开发新型高比能密度锂离子电池体系。我们将通过设计和优化材料合成方法，实现具有纳米复合结构的目标材料的可控合成，并探索兼容的高压电解质体系。将采用不同的技术系统地研究材料和相应电解质的电化学性能。电化学反应机理和材料结构与性能之间的关系也将通过不同的先进技术（如基于原位同步辐射的XRD，硬和软x射线吸收技术，固态核磁共振和在线质谱）结合第一性原理计算来表征。我们期望对晶体和局部结构的演化、离子的价态变化和正负离子的排序、氧的演化和界面性质等方面有更多的了解。相信这些信息和数据将加深我们对O2-和O(2-m)-的平衡关系、新型阴离子氧化还原工艺的利用规模的认识。这些结果将影响未来新一代正极材料和兼容的高压电解质体系的研发，最终实现高能量密度的锂离子电池。

This project will combine the experiments and theory methods to study the new generation of high-capacity positive electrode materials Li2(M1/M2)O3 (M1, M2 = Mn, Ru, Ni, Co, etc.) and compatible electrolytes for Li-ion batteries, construct and develop novel Li-ion battery system with high specific energy density. We will do controllable synthesis of the target materials with nano-composite structure via designing and optimizing materials synthesis methods, and explore the compatible high-voltage electrolyte systems. The electrochemical performance of the materials and corresponding electrolytes will be investigated systematically with different techniques. The electrochemical reaction mechanisms and the relationship between material structure and performance will also be characterized by different advanced techniques (such as in situ synchrotron radiation-based XRD, hard & soft X-ray absorption techniques, solid state NMR and on line mass spectroscopy) combining with first-principles calculations. We expected to get information and more understanding of crystal and local structural evolution, ionic valence changes and cation/anion ordering, oxygen evolution and interfacial properties etc. It is believed that such information and data will deepen our understanding of equilibrium relationship between O2- and O(2-m)-, utilization scale of new anionic redox process. These results will impact the future R&D of new generation of positive electrode materials and the compatible high-voltage electrolyte systems, finally the Li-ion batteries with high-energy density.