High-energy density graphite/AC capacitor in organic electrolyte
High-energy density graphite/AC capacitor in organic electrolyte
复制标题
DOI：
10.1016/j.jpowsour.2007.11.101
复制
发表时间：
2008-03-01
影响因子：
9.2
通讯作者：
Beguin, F.
中科院分区：
文献类型：
--
作者：
Khomenko, V.;Raymundo-Pinero, E.;Beguin, F.
在有机电解质（1:1 碳酸乙烯酯 (EC)/碳酸二甲酯 (DMC) 中的 1 mol L-1 LiPF6）中设计了一种高能量密度混合电容器，分别使用商业级石墨和活性炭作为负极和正极。人们已经探索了不同的方法来组装混合电容器，以实现能量和功率密度之间的最佳比率，同时保持长循环寿命的能力。在优化的混合电容器中，正极的电位范围相对于Li/Li+为1.5至5V，扩展到有机电解质中活性炭的整个稳定窗口，而负极的电位几乎保持恒定在相对于Li/Li+的0.1V左右。在仔细平衡电极各自的质量并适当格式化系统后，发现 4.5V 的电压是避免混合电容器在循环过程中电容衰减的最佳值。重量能量密度和体积能量密度分别高达103.8 Wh kg(-1) 和111.8 Wh L-1。体积能量密度的显着值比使用相同活性炭构建的对称或不对称电容器高 10 倍。 (C) 2007 Elsevier B.V. 保留所有权利。
A high-energy density hybrid capacitor has been designed in organic electrolyte (1 mol L-1 LiPF6 in 1:1 ethylene carbonate (EC)/dimethyl carbonate (DMC)) using commercial grades of graphite and activated carbon for negative and positive electrodes, respectively. Different approaches have been explored for assembling the hybrid capacitor in order to achieve an optimum ratio between the energy and power density, while keeping a long cycle-life capability. In the optimized hybrid capacitor, the potential of the positive electrode ranges from 1.5 up to 5 V vs. Li/Li+, being extended to the whole stability window of the activated carbon in the organic electrolyte, whereas the potential of the negative electrode remains almost constant at around 0.1 V vs. Li/Li+. After balancing carefully the respective masses of the electrodes and appropriately formatting the system, it was found that a voltage of 4.5 V is the optimal value for avoiding a capacitance fading of the hybrid capacitor during cycling. Gravimetric and volumetric energy densities as high as 103.8 Wh kg(-1) and 111.8 Wh L-1, respectively, were obtained. The noticeable value of volumetric energy density is 10 times higher than for symmetric or asymmetric capacitors built with the same activated carbon. (C) 2007 Elsevier B.V. All rights reserved.