Tungsten oxide-based electrochromic devices, owing to their high optical modulation, low driving voltage, and excellent memory effect, are widely regarded as one of the most promising technologies for commercial smart windows and static displays. However, insufficient cycling stability remains a critical bottleneck restricting their transition from the laboratory to practical applications: during prolonged ion insertion/extraction processes, the ‘ion trapping’ effect and microstructural degradation jointly lead to continuous decay in charge capacity and deterioration in optical contrast, with device lifetimes often limited to the order of several thousand cycles. To address this critical challenge, our team has focused on the scientific question of "how to suppress irreversible cation accumulation and achieve more uniform distribution of injected cations," systematically investigating the overall accumulation behavior of tungsten oxide films, the suppression of the overall cation accumulation effect through oxygen vacancy engineering, and the regulation of injected cation distribution uniformity via current and geometric configuration of the current collector, thereby significantly enhancing the cycling stability of tungsten oxide-based electrochromic devices.
 

Cycling-Stability