Electrochromic technology has gained significant attention in various fields such as displays,smart windows,biomedical monitoring,military camouflage,human-machine interaction,and electronic skin due to its ability to...Electrochromic technology has gained significant attention in various fields such as displays,smart windows,biomedical monitoring,military camouflage,human-machine interaction,and electronic skin due to its ability to provide reversible and fast color changes under applied voltage.With the rapid development and increasing demand for flexible electronics,flexible electrochromic devices(FECDs)that offer smarter and more controllable light modulation hold great promise for practical applications.The electrochromic material(ECM)undergoing color changes during the electrochemical reactions is one of the key components in electrochromic devices.Among the ECMs,viologens,a family of organic small molecules with 1,1'-disubstituted-4,4'-dipyridinium salts,have garnered extensive research interest,due to their well-reversible redox reactions,excellent electron acceptance ability,and the ability to produce multiple colors.Notably,viologen-based FECDs demonstrate color changes in the liquid or semisolid electrolyte layer,eliminating the need for two solid electrodes and thus simplifying the device structure.Consequently,viologens offer significant potential for the development of FECDs with high optical contrast,fast response speed,and excellent stability.This review aims to provide a comprehensive overview of the progress and perspectives of viologen-based FECDs.It begins by summarizing the typical structure and recent exciting developments in viologen-based FECDs,along with their advantages and disadvantages.Furthermore,the review discusses recent advancements in FECDs with additional functionalities such as sensing,photochromism,and energy storage.Finally,the remaining challenges and potential research directions for the future of viologen-based FECDs are addressed.展开更多
Electrochromic materials are capable of reversibly switching their colors or optical properties through redox reactions under applied voltages,which have shown great potential applications including smart windows,none...Electrochromic materials are capable of reversibly switching their colors or optical properties through redox reactions under applied voltages,which have shown great potential applications including smart windows,nonemissive displays,optical filters,among others.Although the current rigid electrochromic devices have shown emerging interest and developed rapidly,many applications(e.g.,wearable/deformable optoelectronics)are blocked due to their inflexible features.Herein,the adaption of rigid electrochromic devices to flexible ones is of particular interest for the new era of smart optoelectronics.In this review,the current state-of-the-art achievements of flexible electrochromic devices(FECDs)are highlighted,along with their design strategies and the choice of electrochromic materials.The recent research progress of FECDs is reviewed in detail,and the challenges and corresponding solutions for real-world applications of FECDs are discussed.Furthermore,we summarize the basic fabrication strategies of FECDs and their potential applications.In addition,the development trend,the perspectives,and the outlook of FECDs are discussed at the end of this Review,which may provide recommendations and potential directions to advance the practical applications of FECDs.展开更多
With the increasing interest in the application of electrochromism to flexible and wearable electronics in recent years,flexible electrochromic devices(ECDs)that can function at extreme temperatures are required.Howev...With the increasing interest in the application of electrochromism to flexible and wearable electronics in recent years,flexible electrochromic devices(ECDs)that can function at extreme temperatures are required.However,the functionalities of flexible ECDs are severely hampered by the inadequate choice of electrolytes,which might ultimately result in performance fading during low-and high-temperature operations.Here,we develop a deep eutectic solvent(DES)-based gel electrolyte that can maintain its optical,electrical,and mechanical properties over a wide range of temperatures(-40 to 150℃),exhibiting an extremely high visible-range transmittance over 90%,ion conductivity of 0.63 mS cm^(-1),and fracture strain exceeding 2000%.Owing to the excellent processability of the DES-based electrolytes,provided by dynamic interactions such as the lithium and hydrogen bonding between the DES and polymer matrix,a directly written patterning in ECDs is realized for the first time.The fabricated ECDs exhibit an excellent electrochromic behavior superior to the behavior of the ECDs fabricated with traditional gel electrolytes.The introduction of such DES-based electrolytes is expected to pave the way for a widespread application of electrochromic products.展开更多
Flexible electrochromic devices (FECDs) are promising candidates for the next generation of wearable electronics due to their low operating voltage and energy consumption. For the flexible electrochromic devices, the ...Flexible electrochromic devices (FECDs) are promising candidates for the next generation of wearable electronics due to their low operating voltage and energy consumption. For the flexible electrochromic devices, the electrolyte is an important component. Typically, the electrolyte needs to be formulated according to the device structure and usage scenario. A high-performance electrolyte involves consideration of many factors, including choosing the right polymer, solvent, curing agent, and ion type to satisfy particular device specifications. In this work, a ultraviolet-curable solid–liquid host–guest (UV-SLHG) electrolyte is developed. Several aspects of performance are improved by introducing the solid–liquid coexisting microstructure without changing the electrolyte formulation, including excellent adhesion, a 30% increase in tensile characteristics, and a seven-fold increase in ionic conductivity when compared to a fully cured solid-state electrolyte. More importantly, the unique advantage of SLHG electrolytes lies that the thickness will not change significantly during bending. The FECD made by using the UV-SLHG-based electrolyte sustained 10,000 bending cycles at the bending radius of 2.5 mm while maintaining outstanding optical modulation. A wearable ring-type ECD and a battery-free FECD wine label were made as demonstrators. The UV-SLHG strategy is not only suitable for the FECDs but also universally applicable to other electrolyte-based of flexible electronics such as flexible capacitors and batteries.展开更多
基金financial support from the National Natural Science Foundation of China(22105106)the Natural Science Foundation of Jiangsu Province of China(BK20210603)+1 种基金the Nanjing Science and Technology Innovation Project for overseas Students(NJKCZYZZ2022–05)the Start-up Funding from NUPTSF(NY221003)。
文摘Electrochromic technology has gained significant attention in various fields such as displays,smart windows,biomedical monitoring,military camouflage,human-machine interaction,and electronic skin due to its ability to provide reversible and fast color changes under applied voltage.With the rapid development and increasing demand for flexible electronics,flexible electrochromic devices(FECDs)that offer smarter and more controllable light modulation hold great promise for practical applications.The electrochromic material(ECM)undergoing color changes during the electrochemical reactions is one of the key components in electrochromic devices.Among the ECMs,viologens,a family of organic small molecules with 1,1'-disubstituted-4,4'-dipyridinium salts,have garnered extensive research interest,due to their well-reversible redox reactions,excellent electron acceptance ability,and the ability to produce multiple colors.Notably,viologen-based FECDs demonstrate color changes in the liquid or semisolid electrolyte layer,eliminating the need for two solid electrodes and thus simplifying the device structure.Consequently,viologens offer significant potential for the development of FECDs with high optical contrast,fast response speed,and excellent stability.This review aims to provide a comprehensive overview of the progress and perspectives of viologen-based FECDs.It begins by summarizing the typical structure and recent exciting developments in viologen-based FECDs,along with their advantages and disadvantages.Furthermore,the review discusses recent advancements in FECDs with additional functionalities such as sensing,photochromism,and energy storage.Finally,the remaining challenges and potential research directions for the future of viologen-based FECDs are addressed.
基金the support from the “Qilu Young Scholar” program (62460082163097) of Shandong Universitythe National Natural Science Foundation of China (62105185)+1 种基金Shandong Excellent Young Scientists Fund Program (Overseas) (2022HWYQ-021)Guangdong Basic and Applied Basic Research Foundation (2022A1515011516)
文摘Electrochromic materials are capable of reversibly switching their colors or optical properties through redox reactions under applied voltages,which have shown great potential applications including smart windows,nonemissive displays,optical filters,among others.Although the current rigid electrochromic devices have shown emerging interest and developed rapidly,many applications(e.g.,wearable/deformable optoelectronics)are blocked due to their inflexible features.Herein,the adaption of rigid electrochromic devices to flexible ones is of particular interest for the new era of smart optoelectronics.In this review,the current state-of-the-art achievements of flexible electrochromic devices(FECDs)are highlighted,along with their design strategies and the choice of electrochromic materials.The recent research progress of FECDs is reviewed in detail,and the challenges and corresponding solutions for real-world applications of FECDs are discussed.Furthermore,we summarize the basic fabrication strategies of FECDs and their potential applications.In addition,the development trend,the perspectives,and the outlook of FECDs are discussed at the end of this Review,which may provide recommendations and potential directions to advance the practical applications of FECDs.
基金External Cooperation Program of the Chinese Academy of Sciences,Grant/Award Number:121E32KYSB20190008National Natural Science Foundation of China,Grant/Award Numbers:22175198,51972331,52172299+3 种基金Outstanding Youth Fund of Jiangxi,Grant/Award Number:20192BCBL23027Six Talent Peaks Project in Jiangsu Province,Grant/Award Number:XCL-170the National Key Research and Development Program of China,Grant/Award Number:2020YFB1505703Youth Innovation Promotion Association of the Chinese Academy of Sciences,Grant/Award Number:2018356.
文摘With the increasing interest in the application of electrochromism to flexible and wearable electronics in recent years,flexible electrochromic devices(ECDs)that can function at extreme temperatures are required.However,the functionalities of flexible ECDs are severely hampered by the inadequate choice of electrolytes,which might ultimately result in performance fading during low-and high-temperature operations.Here,we develop a deep eutectic solvent(DES)-based gel electrolyte that can maintain its optical,electrical,and mechanical properties over a wide range of temperatures(-40 to 150℃),exhibiting an extremely high visible-range transmittance over 90%,ion conductivity of 0.63 mS cm^(-1),and fracture strain exceeding 2000%.Owing to the excellent processability of the DES-based electrolytes,provided by dynamic interactions such as the lithium and hydrogen bonding between the DES and polymer matrix,a directly written patterning in ECDs is realized for the first time.The fabricated ECDs exhibit an excellent electrochromic behavior superior to the behavior of the ECDs fabricated with traditional gel electrolytes.The introduction of such DES-based electrolytes is expected to pave the way for a widespread application of electrochromic products.
基金supported by the NSFC(No.22002051)Jiangsu Provincial Double-Innovation Doctor Program(No.JSSCBS20210931)+4 种基金the Innovation/Entrepreneurship Program of Jiangsu Province(No.JSSCTD202146)China Postdoctoral Science Fund(No.2021M701484)Jiangsu Postdoctoral Fund(No.2021K251B)QD-NLED device structure optimization and electroluminescence mechanism research project(No.2022YFB3606503)Jiangsu Funding Program for Excellent Postdoctoral Talent.The authors are grateful for the technical support for Nano-X from Suzhou Institute of Nano-Tech and NanoBionics,Chinese Academy of Sciences(SINANO).
文摘Flexible electrochromic devices (FECDs) are promising candidates for the next generation of wearable electronics due to their low operating voltage and energy consumption. For the flexible electrochromic devices, the electrolyte is an important component. Typically, the electrolyte needs to be formulated according to the device structure and usage scenario. A high-performance electrolyte involves consideration of many factors, including choosing the right polymer, solvent, curing agent, and ion type to satisfy particular device specifications. In this work, a ultraviolet-curable solid–liquid host–guest (UV-SLHG) electrolyte is developed. Several aspects of performance are improved by introducing the solid–liquid coexisting microstructure without changing the electrolyte formulation, including excellent adhesion, a 30% increase in tensile characteristics, and a seven-fold increase in ionic conductivity when compared to a fully cured solid-state electrolyte. More importantly, the unique advantage of SLHG electrolytes lies that the thickness will not change significantly during bending. The FECD made by using the UV-SLHG-based electrolyte sustained 10,000 bending cycles at the bending radius of 2.5 mm while maintaining outstanding optical modulation. A wearable ring-type ECD and a battery-free FECD wine label were made as demonstrators. The UV-SLHG strategy is not only suitable for the FECDs but also universally applicable to other electrolyte-based of flexible electronics such as flexible capacitors and batteries.