基于MXenes表面氧/硫改性的碱金属离子电池负极材料设计

负极材料是碱金属离子电池的核心部件之一，但目前市场上负极材料存在不足，限制了电池性能的进一步提升。MXenes材料的M和X原子交替层状排列使其具有用作负极材料独特的结构优势，然而表面官能团对性能的影响和使用时的层间塌陷与再堆积阻碍了它的应用。本项目主要考察表面O官能团与S官能团，以及过渡金属氧化物与过渡金属硫化物对MXenes材料（含掺杂MXenes）的性能影响。先行采用模拟计算的方式对改性条件下MXenes材料的稳定性、导电性、吸附性及碱金属离子扩散性能进行组合筛选，快速准确指出适合不同MXenes材料的氧/硫改性方法，然后进行典型物理实验验证，并通过详细模拟计算探讨MXenes材料改性规律和物理本质。该方式克服了传统实验模式下材料开发速度缓慢和方案设计缺乏理论指导的问题。项目拟制备出一批稳定性高、性能优异的新型MXenes基碱金属电池负极材料，以期推动MXenes材料的产业化应用进程。

Negative electrode material (anode materials) is one of the core components of alkali metal ion batteries, but there are some shortcomings of current negative electrode materials in the market, which limits the further improvement of battery performance. The alternating layered arrangement of M and X atoms in MXenes materials provides unique structural advantages as anode materials. However, their applications are impeded by the effect of surface functional groups on the performance and the collapsing and repacking. This project will mainly investigate the effect of surface oxygen functional groups and sulphur functional groups on the properties of MXenes materials (including doped MXenes), as well as the transition metal oxides (TMOs) and transition metal dichalcogenides (TMDCs). Firstly, the stability, conductivity, adsorption and diffusion properties of MXenes materials under modification conditions are calculated and screened by density functional theory (DFT) calculations or molecular dynamics simulations. The suitable modification methods for different MXenes materials are sought quickly and accurately, and then the selective results are verified by physical experiments. The influence law and physical essence of O/S functional groups, TMOs/TMDCs on the properties of MXenes materials will be further investigated by analyzing the density of states, charge density and charge transfer of the modified MXenes. This research model overcomes the problems of slow material development speed and lack of theoretical guidance in the traditional experimental mode. It is hoped to synthesize a batch of MXenes-based anode materials are with high stability and excellent energy storage performance of alkali metal batteries, and promote the industrial application of MXenes materials.