Electrochromic energy storage devices (EESDs) including electrochromic supercapacitors (ESC) and electrochromic batteries (ECB) have received significant recent attention in wearables, smart windows, and colour-changing sunglasses due to their multi-functionality, including colour variation under various charge densities. The performance of EESDs is mainly dependent on the properties of three major components (i) the current collector/substrate (cc/substrate) (ii) the electrolyte and (iii) electrochromic materials (ECM). Among various EESDs, advanced flexible or stretchable devices offer better functionality than conventional rigid glass-based devices and are easily integrated with any curved surface. However, in flexible or stretchable EESDs, delamination, dissociation and degradation critically affect the lifecycle and stable performance and are key issues to solve for widespread deployment of the technology. A detailed review of the materials and their performance as flexible EESDs is therefore propitious for the design and engineering of next-generation ECBs and ESCs. In this review, we considered the importance of various materials and their implementation in flexible and stretchable EESD fabrication along with their potential application in sustainable energy systems.

电致变色储能器件（EESD），包括电致变色超级电容器（ESC）和电致变色电池（ECB），由于其多功能性（包括在不同充电密度下的颜色变化），最近在可穿戴设备、智能窗户和变色太阳镜中受到了极大的关注。EESD 的性能主要取决于三个主要组件的特性（i）集流体/基板（cc/基板）（ii）电解质和（iii）电致变色材料（ECM）。在各种 EESD 中，先进的柔性或可拉伸器件比传统的刚性玻璃器件提供更好的功能，并且可以轻松与任何曲面集成。然而，在柔性或可拉伸的 EESD 中，分层、解离和降解严重影响生命周期和稳定性能，也是该技术广泛部署需要解决的关键问题。因此，对材料及其作为灵活 EESD 的性能进行详细审查有利于下一代 ECB 和 ESC 的设计和工程。在这篇综述中，我们考虑了各种材料的重要性及其在柔性和可拉伸 EESD 制造中的应用，以及它们在可持续能源系统中的潜在应用。