二氧化锰与二维材料复合应用于超级电容器

现如今世界正面临着与能源相关的一系列问题与挑战,科学家们致力于研究绿色高性能的能量存储器件以适应当前乃至以后长久可持续创新发展的需要。超级电容器作为一种新型的绿色能源储存装置,具有功率密度大、理论比电容高、充放电速度快、循环寿命长、安全性高、环境友好且经济等优点,为人类解决能源危机提出了可能。电极材料是影响超级电容器性能的重要因素。近些年,由于二氧化锰基超级电容器具有理论比电容高、化学稳定性好、环境友好等特点被广泛研究。同时多种二维材料也继石墨烯后被相继用作超级电容器电极材料,具有二维结构特征材料在提高双电层电容器的能量密度、改善赝电容电容器方面发挥着重要作用。实现高比电容和高倍率性能,将二氧化锰与二维材料复合将不失为一个有前景的选择。本文系统介绍了以石墨烯为代表的各类二维材料与二氧化锰复合物在超级电容器中的应用研究,并聚焦于这些二维材料与二氧化锰复合后所展现的优异电化学性能。

Composite of Manganese Dioxide and Two-dimensional Materials Applied to Supercapacitors

The world is currently facing a series of energy-related problems and challenges. In response, scientists are committed to seeking green high-performance energy storage devices to meet the demands of long-term, sustainable, and innovative development in the future. As a new type of green energy storage device, the supercapacitor has the advantages of high power density, high theoretical specific capacitance, fast charge and discharge speed, long cycle life, high safety, environmental friendliness, and economy to help people cope with the energy crisis. In addition, energy storage devices including Li-ion batteries and supercapacitors are being transformed from heavy, rigid, and bulky devices into light, flexible, and small units to fulfill the needs of the next generation. Among these energy storage systems, the electrode material is an important factor affecting the performance of supercapacitors. In recent years, supercapacitors based on manganese dioxide have been widely studied owing to their high theoretical specific capacitance, good chemical stability, and environmental friendliness. At the same time, a variety of two-dimensional materials are also used as supercapacitor electrode materials after graphene. Two-dimensional structural features play an important role in improving the energy density of electric double-layer capacitors and improving the pseudocapacitance of capacitors. To achieve high specific capacitance and high rate of performance, combining manganese dioxide with two-dimensional materials is a promising option. In this paper, we systematically introduce the application of composites that combine two-dimensional materials represented by graphene and manganese dioxide in supercapacitors, and considers the electrochemical properties of these composites. However, there is still a long way to go in order to fabricate a suitable hierarchical structure consisting of two-dimensional materials and manganese dioxide. For example, a suitable two-dimensional material must be chosen and combined with manganese dioxide to form composites that possess excellent electrochemical properties. In addition, the fabrication methods for these composites are a principal factor that affects their performance. Thus, there are reasons for us to strongly believe that if these key issues are resolved, the properties of these composites consisting of manganese dioxide and two-dimensional materials will make great progress. Overall, this paper only points out some general directions for these kinds of composites in the future, such as principles for choosing the two-dimensional materials to combine with manganese dioxide, and the composite methods which have been reported previously. We are pleased that other researchers are being inspired by our work, and we are looking forward to seeing better studies in this field.