Unlike conventional electrochromic devices, Zinc anode-based electrochromic devices (ZECDs) ensure excellent charge balance between the electrochromic layer and Zn anode during the coloring/bleaching by reversible metal deposition/stripping on the Zn anode. Meanwhile, the inherent potential difference between the metal anode and the electrochromic layer can drive the spontaneous coloration/bleaching of ZECDs, featuring energy retrieval functionality. This review discusses the working mechanisms, performance indexes of ZECDs, and the impact of material selection on ZECD performance. Furthermore, we comprehensively summarize the latest research progress of ZECDs in energy storage, smart windows, and multicolor displays. We argue that using high-transparency zinc mesh, additive manufacturing processes, and self-healing electrochromic materials can significantly advance the commercialization of large-area ZECDs. Finally, “electrode-free” device structures, renewable or replaceable electrolytes, and strategies to suppress zinc dendrites are prospected to overcome cost-effectiveness and lifespan issues of ZECDs. This review aims at enabling more efficient and advanced ZECDs for multifunctional applications.

Exploration of alternative energy storage systems has been more than necessary in view of the supply risks haunting lithium-ion batteries. Among various alternative electrochemical energy storage devices, sodium-ion battery outstands with advantages of cost-effectiveness and comparable energy density with lithium-ion batteries. Thanks to the similar electrochemical mechanism, the research and development of lithium-ion batteries have forged a solid foundation for sodium-ion battery explorations. Advancements in sodium-ion batteries have been witnessed in terms of superior electrochemical performance and broader application scenarios. Here, the strategies adopted to optimize the battery components (cathode, anode, electrolyte, separator, binder, current collector, etc.) and the cost, safety, and commercialization issues in sodium-ion batteries are summarized and discussed. Based on these optimization strategies, assembly of functional (flexible, stretchable, self-healable, and self-chargeable) and integrated sodium-ion batteries (−actuators, −sensors, electrochromic, etc.) have been realized. Despite these achievements, challenges including energy density, scalability, trade-off between energy density and functionality, cost, etc. are to be addressed for sodium-ion battery commercialization. This review aims at providing an overview of the up-to-date achievements in sodium-ion batteries and serves to inspire more efforts in designing upgraded sodium-ion batteries.