Electrochromic supercapacitors (ESCs) are appealing for smart electronic device applications due to their advantages of dual-function integration. Unfortunately, the synchronous dual-function evaluation and the essential reaction mechanism are ambiguous. Herein, we constructed a 3D WO_3-x nanowire networks/fluorine-doped tin oxide (WO_3-x NWNs/FTO) bifunctional electrode for ESCs by a solvothermal self-crystal seeding method. The synchronous correspondence relationship between the optical and electrochemical performances of the WO_3-x NWNs/FTO electrode was explored using an operando spectra-electrochemical characterization method. It reveals an excellent areal capacity of 57.57 mF cm⁻² with a high corresponding optical modulation (ΔT) of 85.05% and high optical-electrochemical cycling stability. Furthermore, the synergistic reaction mechanism between the Al³⁺ ion intercalation behavior and the surface pseudocapacitance reaction during electrochemical cycling is revealed utilizing in situ X-ray diffraction. Based on these results, an ESC device was constructed by pairing WO_3-x/FTO as the cathode with V₂O₅ nanoflowers/FTO (V₂O₅ NFs/FTO) as the anode, which simultaneously deliver high capacity and large optical modulation. Moreover, the energy storage level of the ESC device could be visually monitored by rapid and reversible color transitions in real time. This work provides a promising pathway to developing multi-functional integrated smart supercapacitors.

电致变色超级电容器 (ESC) 由于其双功能集成的优势而对智能电子设备应用具有吸引力。不幸的是，同步双功能评估和基本反应机制是模棱两可的。在此，我们通过溶剂热自晶种法构建了用于 ESC的 3D WO _3-x纳米线网络/掺氟氧化锡（WO _3-x NWNs/FTO）双功能电极。使用操作谱-电化学表征方法探索了WO _3-x NWNs/FTO电极的光学和电化学性能之间的同步对应关系。它显示了 57.57 mF cm ^-2的出色面积容量具有 85.05% 的高相应光学调制 (ΔT) 和高光电化学循环稳定性。此外，利用原位X射线衍射揭示了电化学循环过程中Al ³⁺离子嵌入行为与表面赝电容反应之间的协同反应机制。基于这些结果，通过将 WO _3-x /FTO 作为阴极与 V ₂ O ₅纳米花/FTO（V ₂ O ₅NFs/FTO）作为阳极，同时提供高容量和大光调制。此外，可以通过快速和可逆的颜色转换实时直观地监控 ESC 设备的能量存储水平。这项工作为开发多功能集成智能超级电容器提供了一条有前途的途径。