Wu Zhisheng, Lian Zhendong, Yan Shanshan, Li Jielei, Xu Jincheng, Chen Shi, Tang Zikang, Wang Shuang-Peng, Ng Kar Wei
Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau 999078, P. R. China.
ACS Nano. 2022 Aug 23;16(8):13199-13210. doi: 10.1021/acsnano.2c06479. Epub 2022 Aug 8.
Aqueous electrochromic battery (ECB) is a multifunctional technology that shows great potential in various applications including energy-saving buildings and wearable batteries with visible energy levels. However, owing to the mismatch between traditional electrochromic materials and the electrolyte, aqueous ECBs generally exhibit poor cycling stability which bottlenecks their practical commercialization. Herein, we present an ultrastable electrochromic system composed of lithium titanate (LiTiO, LTO) electrode and Al/Zn hybrid electrolyte. The fully compatible system exhibits excellent redox reaction reversibility, thus leading to extremely high cycling stabilities in optical contrast (12 500 cycles with unnoticeable degradation) and energy storage (4000 cycles with 82.6% retention of capacity), superior electrochromic performances including high optical contrast (∼74.73%) and fast responses (4.35 s/7.65 s for bleaching/coloring), as well as excellent discharge areal capacity of 151.94 mAh m. The extraordinary cycling stability can be attributed to the robust [TiO] octahedral frameworks which remain chemically active even upon the gradual substitution of Li with Al in LTO over multiple operation cycles. The high-performance electrochromic system demonstrated here not only makes the commercialization of low-cost, high-safety aqueous-based electrochromic devices possible but also provides potential design guidance for LTO-related materials used in aqueous-based energy storage devices.
水系电致变色电池（ECB）是一种多功能技术，在包括节能建筑和具有可见能量水平的可穿戴电池在内的各种应用中显示出巨大潜力。然而，由于传统电致变色材料与电解质之间的不匹配，水系ECB通常表现出较差的循环稳定性，这限制了它们的实际商业化。在此，我们展示了一种由钛酸锂（LiTiO，LTO）电极和Al/Zn混合电解质组成的超稳定电致变色系统。这种完全兼容的系统表现出优异的氧化还原反应可逆性，从而在光学对比度（12500次循环，降解不明显）和能量存储（4000次循环，容量保持率82.6%）方面具有极高的循环稳定性，具有包括高光学对比度（约74.73%）和快速响应（漂白/着色分别为4.35秒/7.65秒）在内的优异电致变色性能，以及151.94 mAh m的优异放电面积容量。这种非凡的循环稳定性可归因于坚固的[TiO]八面体框架，即使在多个操作循环中LTO中的Li逐渐被Al取代时，该框架仍保持化学活性。这里展示的高性能电致变色系统不仅使低成本、高安全性的水系电致变色器件商业化成为可能，而且为水系储能器件中使用的LTO相关材料提供了潜在的设计指导。
