高性能纳米层状互穿增韧薄膜电极的构筑及其柔性储能特性研究

Flexible energy storage devices are receiving more and more research endeavors, and hybrid energy storage system is thought to be the most promising strategy to realize high energy density and high power density. Flexible electrode materials have been one of the major issues that still remain unsolved for such bendable energy storage devices. In this proposal, we proposed rationally designed high-performance film electrode with nano-interconnected architecture which composed of N-doped mesoporous graphene and TiO2-B (Bronze Titanium dioxide) nano-belt. Such flexible film will be fabricated by using filtration-assisted self-assembly method and soft-template method. The relationship between nano-architecture and performance will be elaborated in this project. The proposed hybrid film electrode will bring advantages of both mechanical flexibility and enhanced electrochemical properties (in terms of both gravimetric and volumetric performances) by optimizing the internal structure of electrode. On the basis of structural benefits from the electrodes, hybrid Li(Na)-ion capacitors that deliver a comparable energy density to that of Li-ion battery and comparable power density to that of supercapacitor will be assembled. The viability of the proposed flexible hybrid energy storage device provides a potential solution to pave the way for the progress of wearable electronics in the near future.

开发新型柔性储能器件是可移动式储能领域的重要研究前沿，采用混合型电化学储能体系是实现高性能柔性储能器件最为有效的途径之一。而高比容量、高柔韧性电极的构筑是柔性储能研究领域的关键问题。本申请针对当前柔性储能电极中活性材料易脱落、重量/体积比电容无法兼顾以及机械性能鲜有考虑等问题，通过表面化学修饰和纳米重构，采用真空自组装和模板牺牲法将氮掺杂介孔石墨烯纳米片和TiO2-B纳米带构筑成适合混合型柔性储能器件应用的纳米层状互穿增韧薄膜电极。通过精确调控电极微观结构和宏观尺寸，实现重量和体积比电容均优异、倍率性能出众且弯折稳定性强的一体化柔性电极体系。项目预期将阐释修饰机理并理清微（宏）观调控对电极性能的影响规律，揭示“双优”柔性电极的构效关系及相互作用机理，建立起复合柔性薄膜电极修饰、设计及制备的普适化方法。项目研究成果对高性能柔性储能电极的构筑具有重要意义，为柔性储能器件的研究和开发提供科学依据

柔性储能器件的开发是便携式储能领域的最新研究前沿，柔性储能器件的实现及性能的优劣主要取决于柔性电极材料的制备及其电化学性能。兼具高比容、高柔韧性的电极的构筑是柔性储能领域开发的关键问题。基于此，本项目从柔性电极材料的构筑、电化学性能的调控和机理的阐释出发，开展了TiO2-B纳米带增强石墨烯柔性储能电极的制备及性能调控；柔性多级碳基底负载硫化钼/硫化铼储能电极的制备及性能研究；杂元素掺杂对复合储能电极载流子输运性能的提升机理；柔性多级碳基底负载掺杂型硫化钼电极的电催化制氢性能研究；富界面Ni3S2/MoS2杂化碳基电极制备及其碱性析氢性能研究；柔性多级碳基底负载氧化物的光热转换性能研究及调控等工作。在柔性储能电极方面，以TiO2-B纳米带增强石墨烯为柔性电极的柔性混合型锂离子超级电容器表现出114.1 Wh kg-1高的能量密度在功率密度为46.8 W kg-1时；柔性多级碳基底负载硫化钼/硫化铼储能电极作为锂离子电池负极时也表现出高的比容量，好的倍率性能和优异的循环稳定性；进一步通过杂元素掺杂硫化钼/硫化铼提升了硫化钼/硫化铼倍率性能。结合密度泛函数理论计算对倍率性能的解释进行了阐释，认为杂元素掺杂实现了对硫化钼/硫化铼电子结构的调控，改善了电子电导率和离子扩散能垒。另一方面，柔性电极的构筑思路也被扩展到电催化制氢领域，柔性多级碳基阵列的基底所负载的富界面Ni3S2/MoS2复合催化电极在碱性介质中-10 mA cm-2电流密度下的HER过电位低至89 mV，在-100 mA cm-2的较大电流密度下稳定运行时间达50 h。项目研究成果对高性能柔性碳基功能电极的构筑具有重要意义，为新能源的储存及转换的电极研究和商业化利用提供科学依据。