Electrochromic smart windows offer dynamic control of sunshine and solar heat in modern architecture. Yet, how to obtain aesthetically pleasing color tuning states such as gray and black is a great challenge, and the corresponding desorption mechanism in electrochromism is still not well understood. Here, we report one transmissive-to-black NiO electrochromic film assembled by a facile and low-cost electrostatic spray technology, which achieves ultralarge optical modulation, high coloration efficiency, and remarkable energy storage capacity. By in-depth experimental analyses and the first-principle calculations, multistep electrochemical desorption mechanisms of OH– and electrochromic switching kinetics of the NiO film were unveiled. Additionally, the assembled NiO film-based smart energy storage indicator can visually display its energy storage level in real time. Our obtained NiO films and subsequent devices can serve as potential candidates in a broad range of innovative electrochromic applications including multifunctional smart windows, energy-efficient displays, energy-storage indicators, electronic labels, etc.

Polymer‐dispersed liquid crystal (PDLC) devices are truly promising optical modulators for information display, smart window as well as intelligent photoelectronic applications due to their fast switching, large optical modulation as well as cost‐effectiveness. However, realizing highly soft PDLC devices with sensing function remains a grand challenge because of the intrinsic brittleness of traditional transparent conductive electrodes. Here, inspired by spiderweb configuration, a novel type of silver nanowires (AgNWs) micromesh‐based stretchable transparent conductive electrodes (STCEs) is developed to support the realization of soft PDLC device. Benefiting from the embedding design of AgNWs micromesh in polydimethylsiloxane (PDMS), the STCEs can maintain excellent electrical conductivity and transparency even in various extreme conditions such as bending, folding, twisting, stretching as well as multiple chemical corrosion. Further, STCEs with the embedded AgNWs micromesh endow the assembled PDLC device with excellent photoelectrical properties including rapid switching speed (<1 s), large optical modulation (69% at 600 nm), as well as robust mechanical stability (bending over 1000 cycles and stretching to 40%). Moreover, the device displays the pressure sensing function with high sensitivity in response to pressure stimulus. It is conceivable that AgNWs micromesh transparent electrodes will shape the next generation of related soft smart electronics.

Electrochromic devices (ECDs) present promising prospects in developing energy-saving applications, such as smart windows, antiglare mirrors, and information displays. Here, for the first time, we develop a multistep strategy to improve the electrochromic performance by fully using the adsorption/desorption, insertion/extraction, and reversible electrodeposition of Zn 2+ within the ECD based on the specific crystal superstructured Nb 18 W 16 O 93 film. The synergistic electrochemical process based on the Zn 2+ enables comprehensive enhancement of the electrochromic performance, such as large and broad optical modulation up to 87.0%, 96.2%, and 92.8% at 400, 633, and 1200 nm, respectively, remarkable cycling stability of 3500 cycles, and high coloration efficiency of 72.4 cm 2 C −1 . Furthermore, the assembled device delivers outstanding performance in wide-band and large optical modulation in response to a change in voltage. We believe that our multistep regulation in one device could provide a new strategy for developing high-performance ECDs and shed new light on exploring next-generation ECDs in the future.

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