探究层状氧化物正极的容量产生/衰减机理及改性，对碱金属离子电池的发展具有重要意义。本项目拟以主流的锰基氧化物为对象，旨在采用新颖合成，制备系列新型水钠锰矿型纳米材料：MxCyMnO2+δ·nH2O（A=碱金属, B=阳离子（基团）），通过利用其晶体结构、层间空位处结晶水和外来阳离子的协同作用达到改善其电荷存储的目的，并由理论计算结合实验验证，从原子成面上研究其作用机制，建立准确的构效关系。具体包括：首先，在技术层面上，发展一种绿色低成本的自上而下快速可控制备锰氧化物超结构的化学方法，同时获得稳定的利于碱金属离子自由扩散的层膨胀结构。接着，一方面借助磁共振和X射线吸收谱主要技术，研究不同充放电状态电子特性和局域结构、晶相、动力学等信息, 精确揭示储能过程，并着重考察晶格中外来阳离子特异性效应协同共嵌水分子和宿主氧离子对材料结构和电化学过程的影响；另一方面，采用DFT方法，分析性能差异的起源。

The exploration of the capacity storage/decay mechanism and modification of layered oxide cathodes is of great significance for the development of alkali metal ion battery. This proposal will take typical manganese oxide cathode as research object and focus on the preparation of a series of novel birnessite-type nanomaterials, MxCyMnO2+δ·nH2O (M=alkali metal ions，C=foreign cations) using a new synthetic protocol. The charge storage properties are expected to be improved by the synergistic effect between its crystalline structure, crystal water and foreign positive ions incorporated into intrinsic vacancies. By a combination of theoretical calculation and experimental verification, the mechanism of above effect will be investigated at the atomic level and the structure-activity relationship will be eventually clarified. Details are as follows: Firstly, we try to develop an economical and green top-down chemical process for rapid and controllable fabrication of manganese oxide superstructure technically, affording stable interlayer expansion with favorable diffusion property for alkali metal ions. Afterwards, on the one hand, the electronic structure and local structure changes, as well as crystal phase and dynamics information during discharge-charge will be investigated by means of magnetic resonance and X-ray absorption spectroscopy as main technologies to reveal the charge storage process. Especially, the synergistic effect of specific foreign positive ions at the lattice, co-embedded water molecule and host oxygen ion on the host structure and electrochemical process will be discussed; On the other hand, the origin of the performance difference of these cathodes will be analyzed by DFT method.