PEDOT基对电极染料敏化太阳能电池研究进展

染料敏化太阳能电池(DSSC)是新型太阳能电池的研究热点之一,其优异的弱光发电性能被不断探索,同时透明及柔性DSSC在可穿戴设备上的应用也与日俱增。DSSC的循环依靠对电极的作用才能及时高效地完成,因此对电极材料的选择尤为关键。近几年研究者们对对电极材料的研究不断深入,其中可作为DSSC对电极材料使用的高分子导电聚合物聚3,4-乙撑二氧噻吩(PEDOT)因其高导电性、对电解质的催化能力、透明性和柔性等特点受到广泛关注。以含PEDOT或掺杂PEDOT对电极的DSSC为对象,阐述了PEDOT对电极的制备方法,并总结了近几年PEDOT作为DSSC对电极的研究进展。在此基础上,提出未来在电池效率突破研究中应以原位聚合法制备PEDOT对电极为主,以及在大规模工业化生产中应以物理涂覆法为主的观点,为PEDOT对电极DSSC的研究提供依据。     

Controlled dissolution of polystyrene nanobeads: transition from liquid electrolyte to gel electrolyte

The widespread commercialization of dye-sensitized solar cells (DSSCs) remains limited because of the use of highly volatile liquid electrolytes. Recently, gel-type quasi-solid electrolytes containing a polymer additive or inorganic nanomaterial have shown promising results in terms of the cell efficiency. However, most gel electrolytes have serious obstacles for pore-filling because of their high viscosity. Herein, we report the first observation of the transition from a liquid to a gel electrolyte after filling the cell with the liquid electrolyte using the controlled dissolution of polystyrene nanobeads on the counter electrode, suggesting that the pore-filling problem can be diminished in quasi-solid state DSSCs. The time-resolved solidification allows for the preparation of the gel electrolyte without interfering with the cell performance. The optimal DSSC composed of the gel electrolyte exhibits almost the same power conversion efficiency as the liquid electrolyte based DSSC when measured using an AM1.5G solar simulator at 100 mW/cm(2) light illumination. Moreover, the long-term stability of the DSSC was greatly improved.     

Flexible Aqueous Li‐Ion Battery with High Energy and Power Densities

A flexible and wearable aqueous symmetrical lithium‐ion battery is developed using a single LiVPO₄F material as both cathode and anode in a “water‐in‐salt” gel polymer electrolyte. The symmetric lithium‐ion chemistry exhibits high energy and power density and long cycle life, due to the formation of a robust solid electrolyte interphase consisting of Li₂CO₃‐LiF, which enables fast Li‐ion transport. Energy densities of 141 Wh kg^?1, power densities of 20 600 W kg^?1, and output voltage of 2.4 V can be delivered during >4000 cycles, which is far superior to reported aqueous energy storage devices at the same power level. Moreover, the full cell shows unprecedented tolerance to mechanical stress such as bending and cutting, where it not only does not catastrophically fail, as most nonaqueous cells would, but also maintains cell performance and continues to operate in ambient environment, a unique feature apparently derived from the high stability of the “water‐in‐salt” gel polymer electrolyte.     

Nitrogen‐Doped Carbon Encapsulated Mesoporous Vanadium Nitride Nanowires as Self‐Supported Electrodes for Flexible All‐Solid‐State Supercapacitors

Flexible 3D nanoarchitectures have received tremendous interest recently because of their potential applications in flexible/wearable energy storage devices. Herein, 3D intertwined nitrogen‐doped carbon encapsulated mesoporous vanadium nitride nanowires (MVN@NC NWs) are investigated as thin, lightweight, and self‐supported electrodes for flexible supercapacitors (SCs). The MVN NWs have abundant active sites accessible to charge storage, and the N‐doped carbon shell suppresses electrochemical dissolution of the inner MVN NWs in an alkaline electrolyte, leading to excellent capacitive properties. The flexible MVN@NC NWs film electrode delivers a high areal capacitance of 282 mF cm⁻² and exhibits excellent long‐term stability with 91.8% capacitance retention after 12 000 cycles in a KOH electrolyte. All‐solid‐state flexible SCs assembled by sandwiching two flexible MVN@NC NWs film electrodes with alkaline poly(vinyl alcohol) (PVA), sodium polyacrylate, and KOH gel electrolyte boast a high volumetric capacitance of 10.9 F cm⁻³, an energy density of 0.97 mWh cm⁻³, and a power density of 2.72 W cm⁻³ at a current density of 0.051 A cm⁻³ based on the entire cell. By virtue of the excellent mechanical flexibility, high capacitance, and large energy/power density, the self‐supported MVN@NC NWs paper‐like electrodes have large potential applications in portable and wearable flexible electronics.     

A Flexible Stretchable Hydrogel Electrolyte for Healable All‐in‐One Configured Supercapacitors

The development of integrated high‐performance supercapacitors with all‐in‐one configuration, excellent flexibility and autonomously intrinsic self‐healability, and without the extra healable film layers, is still tremendously challenging. Compared to the sandwich‐like laminated structures of supercapacitors with augmented interfacial contact resistance, the flexible healable integrated supercapacitor with all‐in‐one structure could theoretically improve their interfacial contact resistance and energy densities, simplify the tedious device assembly process, prolong the lifetime, and avoid the displacement and delamination of multilayered configurations under deformations. Herein, a flexible healable all‐in‐one configured supercapacitor with excellent flexibility and reliable self‐healing ability by avoiding the extra healable film substrates and the postassembled sandwich‐like laminated structures is developed. The healable all‐in‐one configured supercapacitor is prepared from in situ polymerization and deposition of nanocomposites electrode materials onto the two‐sided faces of the self‐healing hydrogel electrolyte separator. The self‐healing hydrogel film is obtained from the physically crosslinked hydrogel with enormous hydrogen bonds, which can endow the healable capability through dynamic hydrogen bonding. The assembled all‐in‐one configured supercapacitor exhibits enhanced capacitive performance, good cycling stability, reliable self‐healing capability, and excellent flexibility. It holds broad prospects for obtaining various flexible healable all‐in‐one configured supercapacitors for working as portable energy storage devices in wearable electronics.     

Achieving Ultrahigh Energy Density and Long Durability in a Flexible Rechargeable Quasi‐Solid‐State Zn–MnO2 Battery

Advanced flexible batteries with high energy density and long cycle life are an important research target. Herein, the first paradigm of a high‐performance and stable flexible rechargeable quasi‐solid‐state Zn–MnO₂ battery is constructed by engineering MnO₂ electrodes and gel electrolyte. Benefiting from a poly(3,4‐ethylenedioxythiophene) (PEDOT) buffer layer and a Mn²⁺‐based neutral electrolyte, the fabricated Zn–MnO₂@PEDOT battery presents a remarkable capacity of 366.6 mA h g^?1 and good cycling performance (83.7% after 300 cycles) in aqueous electrolyte. More importantly, when using PVA/ZnCl₂/MnSO₄ gel as electrolyte, the as‐fabricated quasi‐solid‐state Zn–MnO₂@PEDOT battery remains highly rechargeable, maintaining more than 77.7% of its initial capacity and nearly 100% Coulombic efficiency after 300 cycles. Moreover, this flexible quasi‐solid‐state Zn–MnO₂ battery achieves an admirable energy density of 504.9 W h kg^?1 (33.95 mW h cm^?3), together with a peak power density of 8.6 kW kg^?1, substantially higher than most recently reported flexible energy‐storage devices. With the merits of impressive energy density and durability, this highly flexible rechargeable Zn–MnO₂ battery opens new opportunities for powering portable and wearable electronics.     

Printable Fabrication of Nanocoral‐Structured Electrodes for High‐Performance Flexible and Planar Supercapacitor with Artistic Design

Planar supercapacitors with high flexibility, desirable operation safety, and high performance are considered as attractive candidates to serve as energy‐storage devices for portable and wearable electronics. Here, a scalable and printable technique is adopted to construct novel and unique hierarchical nanocoral structures as the interdigitated electrodes on flexible substrates. The as‐fabricated flexible all‐solid‐state planar supercapacitors with nanocoral structures achieve areal capacitance up to 52.9 mF cm^?2, which is 2.5 times that of devices without nanocoral structures, and this figure‐of‐merit is among the highest in the literature for the same category of devices. More interestingly, due to utilization of the inkjet‐printing technique, excellent versatility on electrode‐pattern artistic design is achieved. Particularly, working supercapacitors with artistically designed patterns are demonstrated. Meanwhile, the high scalability of such a printable method is also demonstrated by fabrication of large‐sized artistic supercapacitors serving as energy‐storage devices in a wearable self‐powered system as a proof of concept.     

3D Interdigital Au/MnO2/Au Stacked Hybrid Electrodes for On‐Chip Microsupercapacitors

On‐chip microsupercapacitors (MSCs) have application in powering microelectronic devices. Most of previous MSCs are made from carbon materials, which have high power but low energy density. In this work, 3D interdigital Au/MnO₂/Au stacked MSCs have been fabricated based on laser printed flexible templates. This vertical‐stacked electrode configuration can effectively increase the contact area between MnO₂ active layer and Au conductive layer, and thus improve the electron transport and electrolyte ion diffusion, resulting in enhanced pseudocapacitive performance of MnO₂. The stacked electrode can achieve an areal capacitance up to 11.9 mF cm^?2. Flexible and all‐solid‐state MSCs are assembled based on the sandwich hybrid electrodes and PVA/LiClO₄ gel electrolyte and show outstanding high‐rate capacity and mechanical flexibility. The laser printing technique in this work combined with the physical sputtering and electrodeposition allows fabrication of MSC array with random sizes and patterns, making them promising power sources for small‐scale flexible microelectronic energy storage systems (e.g., next‐generation smart phones).     

Synthesis of P‐Doped and NiCo‐Hybridized Graphene‐Based Fibers for Flexible Asymmetrical Solid‐State Micro‐Energy Storage Device

Fiber supercapacitors (FSCs) are promising energy storage devices in portable and wearable smart electronics. Currently, a major challenge for FSCs is simultaneously achieving high volumetric energy and power densities. Herein, the microscale fiber electrode is designed by using carbon fibers as substrates and capillary channels as microreactors to space‐confined hydrothermal assembling. As P‐doped graphene oxide/carbon fiber (PGO/CF) and NiCo₂O₄‐based graphene oxide/carbon fiber (NCGO/CF) electrodes are successfully prepared, their unique hybrid structures exhibit a satisfactory electrochemical performance. An all‐solid‐state PGO/CF//NCGO/CF flexible asymmetric fiber supercapacitor (AFSC) based on the PGO/CF as the negative electrode, NCGO/CF hybrid electrode as the positive electrode, and poly(vinyl alcohol)/potassium hydroxide as the electrolyte is successfully assembled. The AFSC device delivers a higher volumetric energy density of 36.77 mW h cm^?3 at a power density of 142.5 mW cm^?3. In addition, a double reference electrode system is adopted to analyze and reduce the IR drop, as well as effectively matching negative and positive electrodes, which is conducive for the optimization and improvement of energy density. For the AFSC device, its better flexibility and electrochemical properties create a promising potential for high‐performance micro‐supercapacitors. Furthermore, the introduction of the double reference electrode system provides an interesting method for the study on the electrochemical performances of two‐electrode systems.     

Self‐Healing Micellar Ion Gels Based on Multiple Hydrogen Bonding

Ion gels, composed of macromolecular networks filled by ionic liquids (ILs), are promising candidate soft solid electrolytes for use in wearable/flexible electronic devices. In this context, the introduction of a self‐healing function would significantly improve the long‐term durability of ion gels subject to mechanical loading. Nevertheless, compared to hydrogels and organogels, the self‐healing of ion gels has barely investigated been because of there being insufficient understanding of the interactions between polymers and ILs. Herein, a new class of supramolecular micellar ion gel composed of a diblock copolymer and a hydrophobic IL, which exhibits self‐healing at room temperature, is presented. The diblock copolymer has an IL‐phobic block and a hydrogen‐bonding block with hydrogen‐bond‐accepting and donating units. By combining the IL and the diblock copolymer, micellar ion gels are prepared in which the IL phobic blocks form a jammed micelle core, whereas coronal chains interact with each other via multiple hydrogen bonds. These hydrogen bonds between the coronal chains in the IL endow the ion gel with a high level of mechanical strength as well as rapid self‐healing at room temperature without the need for any external stimuli such as light or elevated temperatures.     

Recent Advances on Self‐Supported Arrayed Bifunctional Oxygen Electrocatalysts for Flexible Solid‐State Zn–Air Batteries

Flexible solid‐state Zn–air batteries have been rapidly developed benefiting from the uprising demand for wearable electronic devices, wherein the air electrode integrated with efficient bifunctional oxygen electrocatalysts plays an important role to achieve high performance. Binder‐free self‐supported bifunctional catalysts can provide large active surface area, fast electron transport path, easy ion diffusion, and excellent structural stability and flexibility, thus acting as promising flexible air cathodes. In this review, recent advances on the application of nanoarrayed electrocatalysts as air cathodes in flexible Zn–air batteries are reviewed. Especially, various types of bifunctional oxygen electrocatalysts, including carbonaceous material arrays, transition metal compound arrays, transition metal/carbon arrays, transition metal compound/carbon arrays, and other hybrid arrays, are discussed. The applications of flexible Zn–air batteries with two configurations (i.e., planar stacks and cable fibers) are also introduced. Finally, perspectives on the optimization of arrayed air cathodes for future development to achieve high‐performance flexible Zn–air batteries are shared.     

Self‐Powered,Flexible, and Solution‐Processable Perovskite Photodetector Based on Low‐Cost Carbon Cloth

Flexible perovskite photodetectors are usually constructed on indium‐tin‐oxide‐coated polymer substrates, which are expensive, fragile, and not resistant to high temperature. Herein, for the first time, a high‐performance flexible perovskite photodetector is fabricated based on low‐cost carbon cloth via a facile solution processable strategy. In this device, perovskite microcrystal and Spiro‐OMeTAD (hole transporting material) blended film act as active materials for light detection, and carbon cloth serves as both a flexible substrate and a conductive electrode. The as‐fabricated photodetector shows a broad spectrum response from ultraviolet to near‐infrared light, high responsivity, fast response speed, long‐term stability, and self‐powered capability. Flexible devices show negligible degradation after several tens of bending cycles and at the extremely bending angle of 180°. This work promises a new technique to construct flexible, high‐performance photodetectors with low cost and self‐powered capability.     

Low-cost quasi-solid-state dye-sensitized solar cells based on a metal-free organic dye and a carbon aerogel counter electrode

Low-cost quasi-solid-state dye-sensitized solar cells (DSSCs) are designed and fabricated by using a metal-free organic dye and a mesoporous carbon aerogel instead of expensive ruthenium-based sensitizers and Pt electrode. The electrospun TiO₂ nanorods are added into a polyvinylidene fluoride (PVDF) solution to form a 3D network nanocomposite gel electrolyte. The presence of TiO₂ nanorods in the gel electrolyte obviously increases the ionic conductivity and decreases charge-transfer resistance of the DSSC. The effects of the gel electrolyte and the carbon aerogel counter electrode on electrochemical and photovoltaic properties have been investigated in detail. Particularly, an optimized DSSC with a nanocomposite gel electrolyte and a carbon aerogel counter electrode affords a power conversion efficiency (PCE) of 6.20% at a light intensity of 100 mW cm⁻².     

Component‐Interaction Reinforced Quasi‐Solid Electrolyte with Multifunctionality for Flexible Li–O2 Battery with Superior Safety under Extreme Conditions

High‐performance flexible lithium–oxygen (Li–O₂) batteries with excellent safety and stability are urgently required due to the rapid development of flexible and wearable devices. Herein, based on an integrated solid‐state design by taking advantage of component‐interaction between poly(vinylidene fluoride‐co‐hexafluoropropylene) and nanofumed silica in polymer matrix, a stable quasi‐solid‐state electrolyte (PS‐QSE) for the Li–O₂ battery is proposed. The as‐assembled Li–O₂ battery containing the PS‐QSE exhibits effectively improved anodic reversibility (over 200 cycles, 850 h) and cycling stability of the battery (89 cycles, nearly 900 h). The improvement is attributed to the stability of the PS‐QSE (including electrochemical, chemical, and mechanical stability), as well as the effective protection of lithium anode from aggressive soluble intermediates generated in cathode. Furthermore, it is demonstrated that the interaction among the components plays a pivotal role in modulating the Li‐ion conducting mechanism in the as‐prepared PS‐QSE. Moreover, the pouch‐type PS‐QSE based Li–O₂ battery also shows wonderful flexibility, tolerating various deformations thanks to its integrated solid‐state design. Furthermore, holes can be punched through the Li–O₂ battery, and it can even be cut into any desired shape, demonstrating exceptional safety. Thus, this type of battery has the potential to meet the demands of tailorability and comformability in flexible and wearable electronics.     

A Highly Stretchable and Real‐Time Healable Supercapacitor

In addition to a high specific capacitance, a large stretchability and self‐healing properties are also essential to improve the practicality and reliability of supercapacitors in portable and wearable electronics. However, the integration of multiple functions into one device remains challenging. Here, the construction of a highly stretchable and real‐time omni‐healable supercapacitor is demonstrated by sandwiching the polypyrrole‐incorporated gold nanoparticle/carbon nanotube (CNT)/poly(acrylamide) (GCP@PPy) hydrogel electrodes with a CNT‐free GCP (GP) hydrogel as the electrolyte and chemically soldering an Ag nanowire film to the hydrogel electrode as the current collector. The newly developed dynamic metal‐thiolate (M‐SR, M = Au, Ag) bond‐induced integrated configuration, with an intrinsically powerful electrode and electrolyte, enables the assembled supercapacitor to deliver an areal capacitance of 885 mF cm^?2 and an energy density of 123 µWh cm^?2, which are among the highest‐reported values for stretchable supercapacitors. Notably, the device exhibits a superhigh stretching strain of 800%, rapid optical healing capability, and significant real‐time healability during the charge–discharge process. The exceptional performance combined with the facile assembly method confirms this multifunctional device as the best performer among all the flexible supercapacitors reported to date.     

All-solid,flexible solar textiles based on dye-sensitized solar cells with ZnO nanorod arrays on stainless steel wires

An all-solid, flexible solar textile fabricated with dye-sensitized solar cells (DSSCs) woven into a satin structure and transparent poly(ethylene terephthalate) (PET) film was demonstrated. A ZnO nanorod (NR) vertically grown from fiber-type conductive stainless steel (SS) wire was utilized as a photoelectrode, and a Pt-coated SS wire was used as a counter electrode. A graft copolymer, i.e. poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM) was synthesized via atom transfer radical polymerization (ATRP) and used as a solid electrolyte. The conditions for the growth of ZnO NR and sufficient dye loading were investigated to improve cell performance. The adhesion of PET films to DSSCs resulted in physical stability improvements without cell performance loss. The solar textile with 10 × 10 wires exhibited an energy conversion efficiency of 2.57% with a short circuit current density of 20.2 mA/cm² at 100 mW/cm² illumination, which is the greatest account of an all-solid, ZnO-based flexible solar textile. DSSC textiles with woven structures are applicable to large-area, roll-to-roll processes.     

Flexible,Flame‐Resistant,and Dendrite‐Impermeable Gel‐Polymer Electrolyte for Li–O2/Air Batteries Workable Under Hurdle Conditions

Gel‐polymer electrolytes are considered as a promising candidate for replacing the liquid electrolytes to address the safety concerns in Li–O₂/air batteries. In this work, by taking advantage of the hydrogen bond between thermoplastic polyurethane and aerogel SiO₂ in gel polymer, a highly crosslinked quasi‐solid electrolyte (FST‐GPE) with multifeatures of high ionic conductivity, high mechanical flexibility, favorable flame resistance, and excellent Li dendrite impermeability is developed. The resulting gel‐polymer Li–O₂/air batteries possess high reaction kinetics and stabilities due to the unique electrode–electrolyte interface and fast O₂ diffusion in cathode, which can achieve up to 250 discharge–charge cycles (over 1000 h) in oxygen gas. Under ambient air atmosphere, excellent performances are observed for coin‐type cells over 20 days and for prototype cells working under extreme bending conditions. Moreover, the FST‐GPE electrolyte also exhibits durability to protect against fire, dendritic Li, and H₂O attack, demonstrating great potential for the design of practical Li–O₂/air batteries.     

Pseudocapacitance of TiO2−x/CNT Anodes for High‐Performance Quasi‐Solid‐State Li‐Ion and Na‐Ion Capacitors

It is challenging for flexible solid‐state hybrid capacitors to achieve high‐energy‐high‐power densities in both Li‐ion and Na‐ion systems, and the kinetics discrepancy between the sluggish faradaic anode and the rapid capacitive cathode is the most critical issue needs to be addressed. To improve Li‐ion/Na‐ion diffusion kinetics, flexible oxygen‐deficient TiO_2?x/CNT composite film with ultrafast electron/ion transport network is constructed as self‐supported and light‐weight anode for a quasi‐solid‐state hybrid capacitor. It is found that the designed porous yolk–shell structure endows large surface area and provides short diffusion length, the oxygen‐deficient composite film can improve electrical conductivity, and enhance ion diffusion kinetic by introducing intercalation pseudocapacitance, therefore resulting in advance electrochemical properties. It exhibits high capacity, excellent rate performance, and long cycle life when utilized as self‐supported anodes for Li‐ion and Na‐ion batteries. When assembled with activated carbon/carbon nanotube (AC/CNT) flexible cathode, using ion conducting gel polymer as the electrolyte, high energy densities of 104 and 109 Wh kg^?1 are achieved at 250 W kg^?1 in quasi‐solid‐state Li‐ion and Na‐ion capacitors (LICs and SICs), respectively. Still, energy densities of 32 and 36 Wh kg^?1 can be maintained at high power densities of 5000 W kg^?1 in LICs and SICs.     

Fabric Organic Electrochemical Transistors for Biosensors

Flexible fabric biosensors can find promising applications in wearable electronics. However, high‐performance fabric biosensors have been rarely reported due to many special requirements in device fabrication. Here, the preparation of organic electrochemical transistors (OECTs) on Nylon fibers is reported. By introducing metal/conductive polymer multilayer electrodes on the fibers, the OECTs show very stable performance during bending tests. The devices with functionalized gates are successfully used as various biosensors with high sensitivity and selectivity. The fiber‐based OECTs are woven together with cotton yarns successfully by using a conventional weaving machine, resulting in flexible and stretchable fabric biosensors with high performance. The fabric sensors show much more stable signals in the analysis of moving aqueous solutions than planar devices due to a capillary effect in fabrics. The fabric devices are integrated in a diaper and remotely operated by using a mobile phone, offering a unique platform for convenient wearable healthcare monitoring.     

Ultraflexible and Lightweight Bamboo‐Derived Transparent Electrodes for Perovskite Solar Cells

Wearable devices are mainly based on plastic substrates, such as polyethylene terephthalate and polyethylene naphthalate, which causes environmental pollution after use due to the long decomposition periods. This work reports on the fabrication of a biodegradable and biocompatible transparent conductive electrode derived from bamboo for flexible perovskite solar cells. The conductive bioelectrode exhibits extremely flexible and light‐weight properties. After bending 3000 times at a 4 mm curvature radius or even undergoing a crumpling test, it still shows excellent electrical performance and negligible decay. The performance of the bamboo‐based bioelectrode perovskite solar cell exhibits a record power conversion efficiency (PCE) of 11.68%, showing the highest efficiency among all reported biomass‐based perovskite solar cells. It is remarkable that this flexible device has a highly bendable mechanical stability, maintaining over 70% of its original PCE during 1000 bending cycles at a 4 mm curvature radius. This work paves the way for perovskite solar cells toward comfortable and environmentally friendly wearable devices.