Pendulum-style integrated dual-function electrochromic energy storage device

Electrochromic device based on zinc anode (ZECD) integrates both electrochromism and energy storage functions within a single system, representing a promising technological advancement for next-generation integrated energy storage devices. This work presents a prototype device demonstrating pendulum-style dual-function electrochromic energy storage system. The system was achieved by incorporating a zinc metal layer as anode into a pendulum-style electrochromic structure, using Prussian Blue/polypyrrole (PB/PPy) and WO 3 /PEDOT:PSS (WO 3 /PP) as two cathode materials. The results show that the composite films significantly enhance the device’s energy storage performance and cycle stability. By using a Zn 2+ /K + dual-ion electrolyte, the coupled anode and cathode form a circuit with high specific capacitance. At a current density of 0.1 mA·cm −2 , the specific capacitance of PB/PPy-Zn is 109.9 mF·cm −2 , with a retention rate of 84.5 % after 2500 cycles. The device can display four different optical states, with an optical contrast as high as 50.1 %. First-principles calculations were also performed, demonstrating that the composite organic materials significantly enhance the charge transfer efficiency of the electrode materials and improve their energy storage performance. The widespread significance of the current pendulum-style integrated device is expected to bring new insights to the field of electrochromic energy storage, with the potential to be applied in broader directions.