全固态柔性非对称微型超级电容器三维多孔石墨烯纳米复合电极研究

With the rapid development of the miniaturized and mechanical-flexible application for portable electronic devices, the exploration of micron-sized and flexible integrated on-chip micro-power systems has become an urgent demand. Micro-supercapacitors not only inherit many advantages of the traditional supercapacitors (i.e., large capacitance, fast charging/discharging rate , long cycle life, good reliability, wide operating temperature range, et al.), but also have reasonable energy density, and are therefore expected to play an important role in a variety of micro-power systems. According to the development objectives of the high-performance micro-supercapacitors, this project is intended to realize an all-solid-state and flexible asymmetric micro-supercapacitor by designing and optimizing the electrode material as well as the device structure on the basis of the microscopic mechanisms and the spatial dimensions of charge storage. We propose the use of the composite electrode materials that combine the highly-conductive three-dimensional porous graphene network and the highly-active nano pseudocapacitance material, together with a novel three-dimensional electrode structure. In this project, the preparation process of the three-dimensional porous graphene and its nano-composite electrode will be studied, along with the device assembly technology. To improve the electrochemical properties and unveil the charge storage mechanisms of the three-dimensional composite electrodes, the microstructure of the active composite electrode material will be regulated by controlling the fabrication parameters, ultimately leading to the realization of the all-solid-state flexible asymmetric micro-supercapacitors with high area capacitance, high energy density, high power density and excellent cycling duration.

随着便携式电子设备面向微型化和柔性化应用的快速发展，开发微小尺寸和柔性的片上可集成微电源系统成为了迫切需求。微型超级电容器继承了传统超级电容器的电容容量大、充放电速度快、循环寿命长、可靠性好、工作温度范围大等诸多优点，并且具有合理的能量密度，因此将在未来各种微电源系统中发挥重要应用。本项目针对高性能微型超级电容器的发展目标，根据电荷存储微观机制及空间维度，对电极材料和器件结构进行优化设计，提出使用高导电性三维多孔石墨烯网络与高活性赝电容纳米材料构成复合电极材料体系，结合新颖的三维电极结构，制备全固态柔性非对称微型超级电容器。项目将研究三维多孔石墨烯及其赝电容纳米复合电极的制备工艺和器件组装技术，通过调控活性材料的微观结构提高电化学特性，并获得三维复合微电极的电荷存储微观机制，最终实现高面积比电容、高能量密度、高功率密度、良好循环特性的全固态柔性微型超级电容器。

微型电化学电容器或微型超级电容器具有电容容量大、充电速度快、循环寿命长、可靠性好、工作温度范围大等优点，在微能量存储领域具有重要的应用前景，可为面向生物、医学和环境等应用的微型低功耗集成电路（如传感器、微处理器和无线通信芯片）提供足够能量和功率。本项目主要针对微型电容器电极材料和器件制备工艺上开展了研究工作。在材料方面，改进了化学分散法制备石墨烯的工艺参数，优化了石墨烯的电化学性能，并制备了石墨烯/MnO2、石墨烯/BN、石墨烯/MoS2复合电极材料；在器件方面，开发模板转移法和镂空模板法两种器件制备工艺，采用镂空模板法制备了全固态柔性石墨烯微型超级电容器，电容器容量在10μA充放电条件下面积比电容达到42.8 mF/cm2，最高能量密度为3.63 mWh/cm3，最高功率密度为4.66 W/cm3，10000 次循环电容量保持率高于90%，在曲率为1.31和3.31的弯曲状态下电容量分别为平面状态的97.3%和93.1%。本项目研制的全固态柔性超级电容器展现了良好的电化学性能，为器件今后的实际应用提供了良好的研究基础。