Aqueous energy storage devices hold great promise for smart electric grids and electric vehicles due to their high ionic conductivity, high safety and low cost, but are often limited by electrode materials with rather low voltage window and sluggish mass transport kinetics through thicker electrode materials. Herein, we design a vanadium oxide@molybdenophosphate composite on oxygen-functionalized carbon substrate with wide potential range of −1.2 to 1.0 V vs. SCE and highly enhanced electron/ion delivery kinetics. The oxygen-functionalized 3D carbon scaffold can bind strongly with VO_x through V-O-C bonding, leading to fast electron transport within electrodes and effective suppresses structural pulverization of oxides. The molybdenophosphate coating layer improves not only the electronic structure and electrical conductivity of VO_x but also the charge storage performance of the composite. Due to those effective interactions, the vanadium oxide@molybdenophosphate composite exhibits an outstanding capacitance of 3,954 mF cm⁻² and good rate capability. Realistically, the assembled symmetric supercapacitor device can operate stably with a voltage window of 2.2 V and delivers extraordinary energy density of 7.56 mWh cm⁻³, which is superior to most advanced supercapacitors. Arbitrary series connection also practices the feasibility of the device as a stand-by power supply for 3C products such as tablets. This innovative synergistic strategy opens up new opportunities for aqueous energy storage.

水性储能装置因其高离子电导率、高安全性和低成本而在智能电网和电动汽车中具有广阔的应用前景，但通常受到具有相当低电压窗口的电极材料和通过较厚电极材料的缓慢传质动力学的限制。在此，我们在氧功能化碳基底上设计了一种氧化钒@钼磷酸盐复合材料，该复合材料具有 -1.2 至 1.0 V vs. SCE 的宽电位范围和高度增强的电子/离子传递动力学。氧功能化的 3D 碳支架可以与 VO _{x牢固结合}通过 VOC 键合，导致电极内的快速电子传输并有效抑制氧化物的结构粉碎。钼磷酸盐涂层不仅改善了VO _x的电子结构和导电性，还改善了复合材料的电荷存储性能。由于这些有效的相互作用，氧化钒@钼磷酸盐复合材料表现出 3,954 mF cm ^-2的出色电容和良好的倍率性能。实际上，组装后的对称超级电容器装置可以在 2.2 V 的电压窗口下稳定运行，并提供 7.56 mWh cm ^{-3的非凡能量密度}，优于最先进的超级电容器。任意串联也实践了该器件作为平板电脑等3C产品备用电源的可行性。这种创新的协同策略为水性储能开辟了新的机遇。