Department of Chemistry, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai, 200092, China.
Small. 2015 Mar 25;11(12):1470-7. doi: 10.1002/smll.201402620. Epub 2014 Nov 3.
A novel hybrid Li-ion capacitor (LIC) with high energy and power densities is constructed by combining an electrochemical double layer capacitor type cathode (graphene hydrogels) with a Li-ion battery type anode (TiO(2) nanobelt arrays). The high power source is provided by the graphene hydrogel cathode, which has a 3D porous network structure and high electrical conductivity, and the counter anode is made of free-standing TiO(2) nanobelt arrays (NBA) grown directly on Ti foil without any ancillary materials. Such a subtle designed hybrid Li-ion capacitor allows rapid electron and ion transport in the non-aqueous electrolyte. Within a voltage range of 0.0-3.8 V, a high energy of 82 Wh kg(-1) is achieved at a power density of 570 W kg(-1). Even at an 8.4 s charge/discharge rate, an energy density as high as 21 Wh kg(-1) can be retained. These results demonstrate that the TiO(2) NBA//graphene hydrogel LIC exhibits higher energy density than supercapacitors and better power density than Li-ion batteries, which makes it a promising electrochemical power source.
一种新型混合锂离子电容器（LIC），兼具高能量和功率密度，通过将电化学双层电容器型阴极（石墨烯水凝胶）与锂离子电池型阳极（TiO2 纳米带阵列）相结合而构建。高功率源由具有 3D 多孔网络结构和高导电性的石墨烯水凝胶阴极提供，而对电极则由直接在 Ti 箔上生长的独立式 TiO2 纳米带阵列（NBA）组成，无需任何辅助材料。这种巧妙设计的混合锂离子电容器允许在非水电解质中快速进行电子和离子传输。在 0.0-3.8 V 的电压范围内，在 570 W kg(-1)的功率密度下可实现 82 Wh kg(-1)的高能量。即使在 8.4 s 的充放电速率下，仍可保持高达 21 Wh kg(-1)的能量密度。这些结果表明，TiO2 NBA//石墨烯水凝胶 LIC 表现出比超级电容器更高的能量密度和比锂离子电池更好的功率密度，使其成为一种很有前途的电化学电源。
