Electrochromic energy storage devices (EESDs) have a wide range of applications from static displays to building windows. However, it is a great challenge to assemble EESDs with both high performance of energy storage and electrochromism. In this work, we design a multifunctional EESD composed of a Li₄Ti₅O₁₂ and a Prussian white. Li₄Ti₅O₁₂ (E = 1.55 V vs Li/Li⁺) film with excellent lithium-ion storage performance is used as the anode, and Prussian white film (E = 3.2 V vs Li/Li⁺) as the cathode. Thanks to the complementary electrochromic behavior, the suitable redox voltage gap, and the intrinsic electrochemical stability of Li₄Ti₅O₁₂ film and Prussian white film, the as-assembled EESD exhibits excellent electrochromic performances including broad optical modulation (55.3% at 529 nm), high coloration efficiency (170.1 cm² C⁻¹), and long-term cycling stability (retention of 95.8% of initial optical modulation after 1000 cycles). And the EESD shows high energy density of 127.2 mWh cm⁻² and exceptionally high power density of 24 mW cm⁻². This EESD with an output voltage of 1.5 V and Coulombic efficiency of 98.8% is promising for applications of electrochromic smart windows and static displays to significantly reduce their energy consumption.

电致变色储能设备 (EESD) 具有从静态显示器到建筑窗户的广泛应用。然而，组装具有高性能储能和电致变色的EESDs是一个巨大的挑战。在这项工作中，我们设计了一种由 Li ₄ Ti ₅ O ₁₂和普鲁士白组成的多功能 EESD 。Li ₄ Ti ₅ O ₁₂ ( E  = 1.55 V vs Li/Li ⁺ ) 薄膜具有优异的锂离子存储性能被用作负极，普鲁士白薄膜 ( E  = 3.2 V vs Li/Li ^{+ )}) 作为阴极。由于互补的电致变色行为、合适的氧化还原电压间隙以及 Li ₄ Ti ₅ O ₁₂膜和普鲁士白膜的固有电化学稳定性，组装好的 EESD 表现出优异的电致变色性能，包括宽光调制（529 nm 处为 55.3% )、高着色效率 (170.1 cm ²  C ^-1 ) 和长期循环稳定性（1000 次循环后保留 95.8% 的初始光学调制）。EESD 显示出 127.2 mWh cm ^{-2 的}高能量密度和 24 mW cm ^{-2 的}超高功率密度. 该 EESD 输出电压为 1.5 V，库仑效率为 98.8%，有望用于电致变色智能窗和静态显示器的应用，以显着降低其能耗。