TRANSITION FROM SUPERCAPACITOR TO BATTERY BEHAVIOR IN ELECTROCHEMICAL ENERGY-STORAGE
TRANSITION FROM SUPERCAPACITOR TO BATTERY BEHAVIOR IN ELECTROCHEMICAL ENERGY-STORAGE
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DOI：
10.1149/1.2085829
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发表时间：
1991-06-01
影响因子：
3.9
通讯作者：
CONWAY, BE
中科院分区：
文献类型：
--
作者：
CONWAY, BE
考虑了电化学能量在电池、“超级电容器”和双层电容器器件中的存储。通过对这些系统的机制和性能的比较，可以识别和区分它们的基本特征，并且可以表征超级电容器和“电池”行为之间过渡的条件。基于二维欠电位沉积反应的超级电容器系统具有高度可逆性，其行为源于与电极衬底表面电活性附着原子的二维覆盖电位依赖性相关的假电容。这种电容可以是相同电极面积的双层电容的10-100倍。与电池行为的本质根本区别在于，在这种系统中，化学和相关电极电位是电荷程度的连续函数，不像单相电池反应物的热力学行为。准二维体系，如超扩展含水RuO2，也表现出较大的赝电容，在这种情况下，这与一系列高度可逆的氧化还原过程有关。这样的氧化物氧化还原体系可以产生最佳的超级电容器性能，并且可以实现每克法拉的电容。其他的例子是导电聚合物电极和Li插层体系。这些系统提供了电池和超级电容器之间的转变的例子，这些转变是由在一个可观的电位范围内出现的氧化/还原程度引起的。描述了RuO2超级电容器的阻抗行为，但与静电电容器的阻抗行为相差甚远。
The storage of electrochemical energy in battery, "supercapacitor," and double-layer capacitor devices is considered. A comparison of the mechanisms and performance of such systems enables their essential features to be recognized and distinguished, and the conditions for transition between supercapacitor and "battery" behavior to be characterized. Supercapacitor systems based on two-dimensional underpotential deposition reactions are highly reversible and their behavior arises from the pseudocapacitance associated with potential-dependence of two-dimensional coverage of electroactive adatoms on an electrode substrate surface. Such capacitance can be 10-100 times the double-layer capacitance of the same electrode area. An essential fundamental difference from battery behavior arises because, in such systems, the chemical and associated electrode potentials are a continuous function of degree of charge, unlike the thermodynamic behavior of single-phase battery reactants. Quasi-two-dimensional systems, such as hyperextended hydrous RuO2, also exhibit large pseudocapacitance which, in this case, is associated with a sequence of redox processes that are highly reversible. Such oxide redox systems give rise to the best supercapacitor behavior and capacitances of farads per gram can be achieved. Other examples are the conducting polymer electrodes and Li intercalate systems. These systems provide examples of the transition between battery and supercapacitor behavior arising from a range of degrees of oxidation/reduction that arise over an appreciable range of potentials. The impedance behavior of an RuO2 supercapacitor is illustrated but is far from that expected for an electrostatic capacitor.