Electrochromic devices (ECDs), which generate reversible color changes by the electrochemical reaction, have shown tremendous promise in the field of smart windows, displays, and the future wearable electronics, due to their benefits of simple structure, low power consumption, as well as multi-colors. In the past decade, two-dimensional (2D) materials, such as graphene, metal oxides/carbides/nitrides/dichalcogenides, conductive polymer, metal-organic frameworks, and covalent organic frameworks, that represent good mechanical properties, superior electrochemical activity, fast charge transfer speed, and other unique physical properties, have been widely applied in the ECDs and induced great improvement of the field. As a result, some long-playing issues of ECDs are in prospect to be settled by using 2D materials. This review starts from summarizing the evaluation standard of ECDs, followed by highlighting the most up-to-date exciting results regarding the design and application of 2D materials for the electrochromic layer. Meanwhile, the superior effects of graphene and MXenes for advanced flexible transparent conducting layer are discussed in detail. At last, the remaining challenges and possible research directions for the future of this field are also proposed. Hopefully, the review may shed light on the main trends for developing high-performance ECDs, and provide referencing value for other researchers, to and finally boost the practical applications of ECDs.

电致变色器件 (ECD) 通过电化学反应产生可逆的颜色变化，由于其结构简单、功耗低以及多色。在过去的十年中，二维（2D）材料，如石墨烯、金属氧化物/碳化物/氮化物/二硫属化物、导电聚合物、金属有机骨架和共价有机骨架，具有良好的机械性能、优异的电化学活性、快速电荷转移速度和其他独特的物理特性已广泛应用于 ECD 并引起该领域的巨大进步。因此，ECD 的一些长期存在的问题有望通过使用 2D 材料来解决。这篇综述从总结ECDs的评价标准开始，然后重点介绍了电致变色层二维材料的设计和应用方面的最新令人兴奋的成果。同时，详细讨论了石墨烯和MXenes用于先进柔性透明导电层的优越效果。最后，还提出了该领域未来面临的挑战和可能的研究方向。希望该综述可以阐明开发高性能 ECD 的主要趋势，并为其他研究人员提供参考价值，最终推动 ECD 的实际应用。详细讨论了石墨烯和 MXenes 在高级柔性透明导电层中的优越效果。最后，还提出了该领域未来面临的挑战和可能的研究方向。希望该综述可以阐明开发高性能 ECD 的主要趋势，并为其他研究人员提供参考价值，最终推动 ECD 的实际应用。详细讨论了石墨烯和 MXenes 在高级柔性透明导电层中的优越效果。最后，还提出了该领域未来面临的挑战和可能的研究方向。希望该综述可以阐明开发高性能 ECD 的主要趋势，并为其他研究人员提供参考价值，最终推动 ECD 的实际应用。