以聚合物凝胶为电解质的多层全固态电变色器件的研究

本文在掺ＬｉＣｌＯ４与碳酸丙烯酯的聚乙二醇固体电解质离子电导特性与ＷＯ３、ＮｉＯ薄膜离子插入性能研究了基础上，设计并制备了互补型ＷＯ３／ＮｉＯ全固态电变色器件。同时研究了该器件变色过程的循环伏安特性与不同状态的可见、近红外透过特性。结果表明，互补型的ＷＯ３／ＰＥＧ－ＬｉＣｌＯ４－ＰＣ／ＮｉＯ器件在可见与近红外均具有良好的电变色特性，其漂白态在波长６００ｎｍ的透过率为７０％，着色态为２０％。     

NIPAM改性PEDOT:PSS导电聚合物的制备及在电致变色器件中的应用

以柔性疏水小分子N-异丙基丙烯酰胺（NIPAM）对聚苯乙烯磺酸盐（PSS）进行共聚改性，制备了一系列聚[(苯乙烯磺酸盐)-共-异丙基丙烯酰胺][P(SS-co-NIPAM)]，并以其为模板采用氧化聚合法与3,4-乙烯二氧噻吩（EDOT）制备了导电聚合物PEDOT:P(SS-co-NIPAM)。与PEDOT:PSS薄膜相比，NIPAM摩尔分数（以对苯乙烯磺酸钠物质的量为基准，下同）为15%时，PEDOT:P(SS-co-NIPAM)薄膜平均透光率保持在80%左右，水接触角从18.5°增至39.0°，疏水性提高，并且弯曲1000次后方阻变化量为5.71 kΩ/sq，远小于PEDOT:PSS薄膜（10.60 kΩ/sq）。以NIPAM摩尔分数为15%的PEDOT:P(SS-co-NIPAM)薄膜作为离子储存层的电致变色器件的光学对比度（ΔT）为9.83%，循环800次后ΔT仍达到9.55%，衰减量为0.28%，衰减量与PEDOT:PSS器件相当，说明NIPAM共聚改性能改善PEDOT:PSS导电聚合物的柔韧性和疏水性，以其作为离子储存层的器件可维持优异的电致变色性能。     

Unraveling Polymer–Ion Interactions in Electrochromic Polymers for their Implementation in Organic Electrochemical Synaptic Devices

Owing to low-power, fast and highly adaptive operability, as well as scalability, electrochemical random-access memory (ECRAM) technology is one of the most promising approaches for neuromorphic computing based on artificial neural networks. Despite recent advances, practical implementation of ECRAMs remains challenging due to several limitations including high write noise, asymmetric weight updates, and insufficient dynamic ranges. Here, inspired by similarities in structural and functional requirements between electrochromic devices and ECRAMs, high-performance, single-transistor and neuromorphic devices based on electrochromic polymers (ECPs) are demonstrated. To effectively translate electrochromism into electrochemical ion memory in polymers, this study systematically investigates polymer–ion interactions, redox activity, mixed ionic–electronic conduction, and stability of ECPs both experimentally and computationally using select electrolytes. The best-performing ECP-electrolyte combination is then implemented into an ECRAM device to further explore synaptic plasticity behaviors. The resulting ECRAM exhibits high linearity and symmetric conductance modulation, high dynamic range (≈1 mS or ≈6x), and high training accuracy (>84% within five training cycles on a standard image recognition dataset), comparable to existing state-of-the-art ECRAMs. This study offers a promising approach to discover and design novel polymer materials for organic ECRAMs and demonstrates potential applications, taking advantage of mature knowledge basis on electrochromic materials and devices.     

High-Performance Aqueous Zn2+/Al3+ Electrochromic Batteries based on Niobium Tungsten Oxides

Electrochromic energy storage devices (EESDs) are incorporating electrochromic and energy storage functions, which can visually display energy storage levels in real-time to promote the next generation of transparent battery development. However, their performances are still limited for practical applications. Herein, a self-powered EESD based on complex niobium tungsten oxide is designed using aqueous Zn²⁺ and hybrid Zn²⁺/Mⁿ⁺ (Mⁿ⁺ = Al³⁺, Mg²⁺, and K⁺) electrolytes. The results reveal that the use of Zn²⁺/Al³⁺ hybrid electrolyte achieves superior electrochromic performances including a short self-coloring time, high optical contrast, and excellent cyclic stability. Furthermore, it is also found that the self-coloring process is accompanied by a high discharged capacity of niobium tungsten oxide, with high optical modulation in the Zn²⁺/Al³⁺ hybrid electrolyte. The detailed mechanism on the performances of EESD using various electrolytes is systematically studied. This work provides a simple and effective strategy for an aqueous and self-powered EESD with high optical contrast and good cycle stability.     

A Piezoelectric-Driven Electrochromic/Electrofluorochromic Dual-Modal Display Device

Electrochromic (EC) reflective displays offer great advantages in delivering information and providing visual data, but are limited in dark environments. Reflective/emissive dual-modal displays capable of electrochemically-induced color and fluorescence change simultaneously are highly desirable, especially possessing rapid response speed as well as long-term durability. Herein, an electroactive fluorescent ionic liquid based on triphenylamine and imidazole (EFIL-TPA) has been synthesized for reflective/emissive dual-modal display. The resultant device exhibits outstanding electrochromic/electrofluorochromic (EC/EFC) performance with low driving voltage (below 1.0 V), fast switching speed (0.57–1.8 s), and remarkable cycling durability (91% retention for 10 000 cycles). A piezoelectric nanogenerator (PENG) driven EC/EFC integrated system is fabricated to harvest energy from human motion and visually drive the color/fluorescence change for human motion indication in both bright and dark environments. This innovative EC/EFC dual-modal display device based on EFIL-TPA supports a huge space for the development of self-powered human motion visualized indication in all-light conditions.     

All-Printed Electrochromic Stickers

Displays are one of the most mature technologies in the field of printed electronics. Their ability to be manufactured in large quantities and at low cost has led to their recent uptake into the consumer market. Within this article this technology is extended to electrochromic display stickers. This is achieved using a recent reverse display architecture screen printed on textile and paper sticker substrates. The electrochromic stickers are comparable to plastic control substrates and show little performance difference even when adhered to curved surfaces. The electrochromic display technology is extended to sticker labels for authentication applications by patterning either the dielectric or the graphical layer. A proof-of-concept prototype emulating a wax seal on an envelope is presented to show that other colors can be implemented in this technology.     

From Amorphous Macroporous Film to 3D Crystalline Nanorod Architecture: A New Approach to Obtain High‐Performance V2O5 Electrochromism

A 3D crystalline V₂O₅ nanorod architecture on indium tin oxide substrates is prepared by simple annealing treatment of a colloidal crystal‐assisted electrodeposited amorphous three‐dimensionally ordered macroporous film at a low temperature of 350 °C. The crystalline nanorods exhibit a low length/diameter ratio with the typical width range of 80–180 nm, length range of 190–500 nm, and thickness of 30–50 nm. Colloidal sphere‐assisted heterogeneous nucleation during electrodeposition and the anisotropic bonding of the V₂O₅‐layered structure are two important factors for the morphological changes. Because of the large surface area, short lithium ion diffusion distance, and good electrolyte penetration, the 3D crystalline V₂O₅ nanorod architecture exhibits a highly reversible Li‐ion insertion/extraction process (columbic efficiency up to 96.9%) with a five‐color‐change electrochromic performance, good transmittance modulation, and acceptable response times (8.8 s for coloration and 9.3 s for bleaching), making it a promising film electrode for electrochromic devices.