3D aperiodic hierarchical porous graphitic carbon material for high-rate electrochemical capacitive energy storage
3D aperiodic hierarchical porous graphitic carbon material for high-rate electrochemical capacitive energy storage
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用于高速电化学电容储能的3D非周期性分级多孔石墨碳材料
DOI：
10.1002/anie.200702721
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发表时间：
2008-01-01
影响因子：
16.6
通讯作者：
Cheng, Hui-Ming
中科院分区：
文献类型：
--
作者：
Wang, Da-Wei;Li, Feng;Cheng, Hui-Ming
电化学电容器(ECs)是混合动力汽车开发中使用的高速电子设备的重要组成部分。这类电容器是基于双电层的电化学电荷调节和法拉第反应的发生。[1]多孔碳材料、过渡金属氧化物和导电聚合物是用作电化学电极材料的基本候选材料。[1]在现有的金属氧化物中，RuO2表现出最好的性能，但它非常昂贵。[2]替代较便宜的氧化物，如NiO，不能在0.6V以上的电压窗口使用；此外，大多数导电聚合物也表现出一些缺点--它们的循环寿命短就是其中之一。[5]因此，多孔碳材料成为最有希望的候选材料，因为它们具有稳定的物理化学性质、良好的导电性、低成本和可用性。[6-8]然而，众所周知，基于多孔碳的EC存在与内部孔内离子传输有关的电极动力学问题。[1，9-12]离子在多孔织构中传输的确切机制非常复杂，因为孔的曲折性、连通性、大小分布和形状，此外，还必须考虑电解液和固液界面的性质。在这些因素中，孔内离子传输阻力和扩散距离是最重要的因素。这两个参数的较大值会导致电极电位降(IR降)和大电流值时的低离子可及表面积(SAccess)，从而严重降低ECS的性能。
Electrochemical capacitors (ECs) are essential components of high-rate electric devices used in the development of hybrid vehicles. Such capacitors are based on electrochemical charge accommodation at the electric double layer and the occurrence of Faradaic reactions.[1] Porous carbon materials, transition-metal oxides, and conducting polymers are fundamental candidates used as EC electrode materials.[1] Among the available metal oxides, RuO2 shows the best performance, but it is very expensive.[2] Alternative cheaper oxides, such as NiO, cannot be used at voltage windows above 0.6 V; furthermore, most of them are poorly conductive.[3–4] Conducting polymers also show some drawbacks—their short cycle life being one of them.[5] As a consequence, porous carbon materials turn out to be the most promising candidates, because of their stable physicochemical properties, good conductivity, low cost, and availability.[6–8] However, porous-carbon-based ECs are known to suffer from electrode kinetic problems that are related to inner-pore ion transport.[1, 9–12] The exact mechanism of ion transport within porous textures is very complex, because the tortuosity, connectivity, size distribution, and shape of the pores, as well as the nature of the electrolyte and the solid–liquid interface, all have to be considered.[1, 13–15] Among these factors, the inner-pore ion-transport resistance and the diffusion distance are the most important ones. Large values of these two parameters lead to a significant electrode-potential drop (IR drop) and a low ion-accessible surface area (Saccess) at large current values, thus severely reducing the performance of the ECs.