Synergistic Effect of Al³⁺/Li⁺-Based All-Solid-State Electrochromic Devices with Robust Performance

In the electrochromic devices (ECDs), the commonly employed active ions are monovalent ions, such as Li+, for the advantages of small ionic radius and high ion transportation. However, monovalent ions still show several disadvantages, including poor chemical stability, expensive costs, difficult waste disposal, and so on. Here, we proposed a synergistic Al3+/Li+ all-solid-state electrochromic device prepared by magnetron sputtering, which extracts the essence of trivalent ion Al3+ and monovalent ion Li+ and remove their dross. It has been demonstrated that the introduction of Li+ ions can activate the Al3+ ions in the solid electrolyte, and both Al3+ and Li+ ions can induce the electrochromic reaction in the all-solid-state ECDs. The synergistic effect of Al3+/Li+ can promote the performance of ECDs, which includes high optical contrast of 56%, fast coloration time of 9.73 s and bleaching time of 2.98 s, and relatively high coloration efficiency of 62.81 cm2·C–1. Our findings are expected to provide a novel strategy for the utilization of trivalent ions in all-solid-state electrochromic devices.