兼具高体积和高质量比容量CoO/Ti3C2Tx柔性多孔自支撑薄膜电极的构筑及储能机理研究

电子储能设备微型、轻薄化的新发展需求，使得设计开发兼具高体积和高质量比容量的电极材料迫在眉睫。目前，高体积比容量碳材料研究已取得一定进展，但其固有储能机制限制了质量容量的提升。过渡金属氧化物具有较高质量比电容，但传统机械压实法提升体积容量时，易堵塞孔道阻碍离子传输，导致质量性能下降。鉴于此，本项目提出利用二维高导电MXene纳米片修饰CoO薄层结构，构筑致密多孔CoO/Ti3C2Tx柔性自支撑膜电极；“致密构建”可有效提升体积比容量，“至柔高导多孔”特征又确保了优异的质量比容量、倍率性能和循环寿命。拟从微观结构演变过程入手，探索致密多孔异质结的可控构筑和形成机理。从界面性质、反应动力学等角度，揭示复合膜结构属性与储能特性间的构效关系，阐明提升性能的关键作用机制。以优化后的复合膜为正极，构筑兼具高质量/体积能量密度和功率密度的储能器件。本项目的实施将为紧凑型储能装置的开发提供新思路。

The new demand of electronic energy storage equipment is miniaturization and thinness, which makes it urgent to design and develop electrode materials with both high volumetric and gravimetric performances. At present, the researches of high volumetric capacitance about carbon materials have made some progress, but its inherent energy storage mechanism limits the improvement of gravimetric capacitance. Transition metal oxides have the advantages of high gravimetric capacitance, yet, using the traditional mechanical compaction method to improve the volumetric capacitance, the pore is easily blocked and the ion transport is impeded, leading to the decrease of gravimetric capacitance. In view of this, the proposal aims to construct a flexible, porous and free-standing CoO/Ti3C2Tx hybrid films electrode without binder by using ultra-thin CoO nanosheet modified by two dimensional MXene. The characteristic of high density can effectively increase the volumetric capacitance, and the soft, high conductivity, rich porous features can ensure the excellent gravimetric capacitance, rate performance and cycle life. The project intends to explore the controllable construction and formation mechanism of porous heterojunction by studying the evolution process of the microstructure. Furthermore, the electrochemical performance enhancement mechanism of the hybrid films electrode is revealed from the perspective of interface properties and reaction kinetics. For further practical application, a flexible hybrid energy-storage device with high volumetric and gravimetric energy density/power density is constructed by coupling optimized CoO/Ti3C2Tx hybrid cathodes with proper anodes. The implementation of this project will provide new ideas and theoretical basis for the development of compact energy storage devices.