Organic small molecules are a very promising kind of materials in energy storage devices because they are green, low-cost and renewable resources. However, the poor electrical conductivity of organic molecules limits their using as electrode materials. The combination of organic molecules and conductive carbon material is a useful method to enhance their electrical conductivity. Here, Gallic acid (Ga) functionalized graphene hydrogel (GH) composite (Ga/GH) was synthesized by a simple hydrothermal method. The Ga/GH composite exhibits outstanding electrochemical capacitance performance because of the incorporation of the Faradaic pseudocapacitance of Ga and the double-layer capacitance of graphene hydrogel. The specific capacitance can reach up to 483 F g⁻¹ at 1 A g⁻¹. In addition, when the current density is increased to 100 A g⁻¹, the rate capability is up to 64.2%. Meanwhile, a Ga/GH//DQ-RGO and a Ga/GH//AC asymmetric capacitor were assembled by using Ga/GH as the positive electrode and 2,6-diaminoanthraquinon functionalized graphene composite (DQ-RGO) and activated carbon (AC) as the negative electrode, respectively. The Ga/GH//DQ-RGO ASC provides an energy density of 27 Wh kg⁻¹ along with a power density of 0.908 kW kg⁻¹ and two such devices in series successfully can illuminate 26 red light-emitting diodes (LEDs). And the Ga/GH//AC ASC provides an energy density of 19.11 Wh kg⁻¹. Two such devices in series can illuminate 20 red light-emitting diodes (LEDs).

有机小分子是一种非常有前景的储能器件材料，因为它们是绿色、低成本和可再生资源。然而，有机分子较差的导电性限制了它们作为电极材料的应用。有机分子与导电碳材料的结合是提高其导电性的有效方法。在这里，没食子酸（Ga）功能化的石墨烯水凝胶（GH）复合材料（Ga/GH）通过简单的水热法合成。由于 Ga 的法拉第赝电容和石墨烯水凝胶的双层电容的结合，Ga/GH 复合材料表现出优异的电化学电容性能。比电容在 1 A g ^-1时可达 483 F g ^-1. 此外，当电流密度增加到100 A g ^-1时，倍率容量可达64.2%。同时，以Ga/GH为正极，2,6-二氨基蒽醌功能化石墨烯复合材料（DQ-RGO）和活性炭组装了Ga/GH//DQ-RGO和Ga/GH//AC不对称电容器（ AC）分别作为负极。Ga/GH//DQ-RGO ASC 提供 27 Wh kg ^-1的能量密度和 0.908 kW kg ^-1的功率密度，两个这样的串联设备可以成功点亮 26 个红色发光二极管 (LED)。Ga/GH//AC ASC提供19.11 Wh kg ^-1的能量密度。两个这样的串联设备可以点亮 20 个红色发光二极管 (LED)。