Processable nanoarchitectonics of two-dimensional metallo-supramolecular polymer for electrochromic energy storage devices with high coloration efficiency and stability

Two-dimensional porous metallo-supramolecular polymers (MSPs) have shown promising prospects for electrochemical-controlled functional devices as their highly reversible metal-centered redox chemistry. How-ever, parallel efforts to solution-processable large-area uniform film based on high-quality MSPs have encoun-tered with limited success. Herein, we develop a scalable method for synthesizing MSP-Fe with gram scale by coordinating 1,3,5-tris(4-(2,2 ':6 ',2 ''-terpyridyl)phenyl)benzene with Fe(II) ions. The uniform MSP-Fe film is assembled on a transparent conductive substrate by electrostatic spray technology. The obtained MSP-Fe films exhibit excellent electrochromic performance and energy storage property simultaneously, such as ultrahigh coloration efficiency of 1103.9 ( +/- 100) cm2 C-1, fast switching speed (< 1.5 s), large optical contrast (> 71.7%), and high specific capacity (12.01 mAh g-1). More importantly, the degradation of optical contrast is only 3% after 10,000 cycles, proving the remarkable cycle stability of the MSP-Fe film. We further demonstrate a smart energy-storage indicator assembled by the MSP-Fe films, in which the energy-storage level is visually perceptible and recognizable in real-time. Furthermore, a large-area semi-solid-state electrochromic device (225 cm2) is successfully constructed based on MSP-Fe films, which achieves a uniform, fast, and reversible color variation across the device.

Automated summary

Researchers have successfully synthesized scalable metallo-supramolecular polymers (MSP-Fe) films with excellent electrochromic and energy storage properties through electrochemical control. The MSP-Fe films exhibit ultra-high coloration efficiency, fast switching speed, large optical contrast, high specific capacity, and remarkable cycle stability. This makes MSP-Fe films highly valuable for electrochemical-controlled functional devices.