Ethoxylated Trimethylolpropane Triacrylate Research Articles

Chiral Janus emulsions with gold nanocomposite for enantioselective catalysis

Chiral emulsions, with the chiral center of chiral-surfactant as the emulsifier, provide opportunities for selective catalysis and inorganic material synthesis. Janus emulsion draws researcher’s attention due to excellent multiple chambers, advanced structures and diverse interfaces. Chiral Janus emulsions are prepared with two immiscible oils of vegetable oil (VO)/dimethyl phthalate (DMP) and 2-(Perfluorooctyl)ethyl methacrylate (PFOEMA)/Ethoxylated trimethylolpropane triacrylate (ETPTA) as inner phases, by emulsified by chiral-surfactant [H-G-C16]FeCl4, in batch-scale by traditional vortex mixing. AuNPs as functional nanomaterials with peroxidase activity are then applied as active centers, adsorbing at the oil/water interface due to the electrostatic interactions between the positive charge of [H-G-C16]FeCl4 at Janus emulsion interfaces and the negative charge of AuNPs modified by SDS. Chiral Janus emulsion is endowed with catalytic activity and enantioselectivity. Catalytic results show two AuNPs@ Janus emulsions show better affinity to catalyze the oxidation of L-DOPA than D-DOPA. By investigating two AuNPs@ Janus emulsions with different inner phases, chiral Janus emulsion of AuNPs@ETPTA/PFOEMA/[H-G-C16]FeCl4(aq) has better catalytic activity and enantioselectivity than AuNPs@DMP/VO/[H-G-C16]FeCl4 (aq) because of the smaller droplets have larger interface areas could adsorb more [H-G-C16]FeCl4 molecules and AuNPs. The findings open an avenue in the production of chiral Janus emulsions with catalytic effect and enantioselectivity, which would push forward future applications in selective catalysis and inorganic material synthesis.

Weak Electrostatic Force on K+ in Gel Polymer Electrolyte Realizes High Ion Transference Number for Quasi Solid-State Potassium Ion Batteries.

Quasi-solid-state potassium-ion batteries (SSPIBs) are of great potential for commercial use due to the abundant reserves and cost-effectiveness of resources, as well as high safety. Gel polymer electrolytes (GPEs) with high ionic conductivity and fast interfacial charge transport are necessary for SSPIBs. Here, the weak electrostatic force between K+ and electronegative functional groups in the ethoxylated trimethylolpropane triacrylate (ETPTA) polymer chains, which can promote fast migration of free K+ , is revealed. To further enhance the interfacial reaction kinetics, a multilayered GPE by in situ growth of poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) on ETPTA (PVDF-HFP|ETPTA|PVDF-HFP) is constructed to improve the interface contact and provide sufficient K+ concentration in PVDF-HFP. A high ion transference number (0.92) and a superior ionic conductivity (5.15 × 10-3 S cm-1 ) are achieved. Consequently, the SSPIBs with both intercalation-type (PB) and conversion-type (PTCDA) cathodes show the best battery performance among all reported SSPIBs of the same cathode. These findings demonstrate that potassium-ion batteries have the potential to surpass Li/Na ion batteries in solid-state systems.

Polymer/ceramic gel electrolyte with in-situ interface forming enhances the performance of lithium metal batteries

With the introduction of solid-state electrolytes, solid-state lithium-metal batteries face enormous challenges of low electrolyte ion conductivity and high electrode electrolyte interface impedance. Here, we adopt a strategy of combining rigidity and flexibility to design a polymer/ceramic composite gel electrolyte films (CSEs) with a fiber like structure and local defect channels for rechargeable lithium metal batteries. The CSEs synthesized in situ on LiFePO4 electrode by ultraviolet (UV) curing method, which combines the high ionic conductivity of Li6.5La3Zr1.5Ta0.5O12 (LLZTO) ceramic particles and the flexibility of poly(vinylidene fluoride-co -hexafluoropropylene) (PVDF-HFP) polymer electrolyte. In order to investigate the effect of crosslinker on the performance of electrolytes, 1,6-hexanediol diacrylate (HDDA) and ethoxylated trimethylolpropane triacrylate (ETPTA) were used in the preparation process of ultraviolet (UV) curing method. A comparison was made between gel electrolytes using HDDA and ETPTA crosslinkers, electrolytes containing ETPTA exhibited good overall performance in terms of ion conductivity (7.89 × 10−4 S cm−1), Li+ transference number (0.63), glass transition temperature (−26.2 °C), good flexibility, thermal stability. As a result, the assembled LiFePO4||electrolytes containing ETPTA||Li batteries exhibit excellent the first discharge capacity (151.9 mAh g−1 with 0.1C), good rate performance and its capacity retention rate is 93.1 % after 300 cycles. This study provides a new strategy for the rational design and process method of high-performance CSEs for rechargeable solid lithium metal batteries.

Introduction of UV-cured interpenetrating polymer network in PEO-based all-solid-state Li-S battery

Lithium–sulfur (Li-S) battery attracts numerous study due to its high theoretical specific capacity. Unfortunately, the notorious shuttle effect and the safety issue of lithium anode limit the development. The application of solid-state electrolyte is regarded as one of the solutions. Herein, a UV-cured polymer network is introduced in poly(ethylene oxide) (PEO)-based solid polymer electrolyte (SPE) to enhance the performance of Li-S battery. Poly(ethylene glycol) dimethacrylate (PEGDMA) was used as the main crosslinking monomer. The abundant -C-C-O- long chain can provide a fast channel for Li+ transfer. Trimethylolpropane ethoxylate triacrylate (TMPETA) is used as the crosslinker, which made the linear copolymer formed by single monomer transform into interpenetrating polymer network. Hence, an interpenetrating UV-cured network was synthesized and combined with PEO. This elaborately designed structure enhances the ionic conductivity and the mechanical properties of PEO SPE as well as hinder the lithium polysulfides (LiPSs) migration. As a result, the symmetric Li cells with this SPE can stably cycle for >1600 h at the current density of 0.1 mA cm−2. Moreover, the Li-S cells can deliver an initial capacity of 1131 mAh g−1 at 0.1C. It provides a thread to design the polymer network of SPE.

Controllable Monodisperse Amphiphilic Janus Microparticles

A facile microfluidic strategy has been successfully developed in this paper for the controllable fabrication of monodisperse amphiphilic Janus microparticles. The fabrication of such amphiphilic Janus microparticles is simply achieved by online UV curing of monodisperse Janus droplet templates that are prepared from microfluidics together with initial fast phase separation induced by co-solvent diffusion and sequential dewetting triggered by interfacial energy. Benefitting from the superiorities of droplet microfluidics, the morphologies of Janus microparticles can be flexibly and precisely controlled by adjusting the flowrates of fluids and the compositions of dispersed phase. Meanwhile, the functionalization of Janus microparticles can be easily realized by introducing certain elements into the dispersed phase to rationally design the bulbs with diverse advanced functions. We also demonstrate the universality of the proposed strategy through the fabrication of monodisperse Janus microparticles with one bulb consisting of hydrophobic poly(ethoxylated trimethylolpropane triacrylate) and another bulb consisting of a hydrophilic hydrogel such as poly(N-isopropyl acrylamide), poly(N-vinylcaprolactam), or polyacrylamide. The thermoresponsive hydrophilic/hydrophobic phase transition property of the poly(N-isopropyl acrylamide) bulb enables the Janus microparticles to be used as functional colloidal surfactants for adjusting the stability/instability of oil–water interface. Our strategy provides a versatile and efficient way to fabricate monodisperse amphiphilic Janus microparticles with controlled structures and diverse functions, which show great application potentials in plenty of fields.

Competitive Li+ Coordination in Ionogel Electrolytes for Enhanced Li-Ion Transport Kinetics.

Developing ionogel electrolytes based on ionic liquid instead of volatile liquid in gel polymer electrolytes is regarded to be effective to diminish safety concerns in terms of overheating and fire. Herein, a zwitterion-based copolymer matrix based on the copolymerization of trimethylolpropane ethoxylate triacrylate (ETPTA) and 2-methacryloyloxyethylphosphorylcholine (MPC, one typical zwitterion) is developed. It is shown that introducing zwitterions into ionogel electrolytes can effectively optimize local lithium-ion (Li+ ) coordination environment to improve Li+ transport kinetics. The interactions between Li+ and bis(trifluoromethanesulfonyl)imide (TFSI- )/MPC lead to the formation of Li+ coordination shell jointly occupied by MPC and TFSI- . Benefiting from the competitive Li+ attraction of TFSI- and MPC, the energy barrier of Li+ desolvation is sharply decreased and thus the room-temperature ionic conductivity can reach a value of 4.4×10-4 S cm-1 . Besides, the coulombic interaction between TFSI- and MPC can greatly decrease the reduction stability of TFSI- , boosting insitu derivation of LiF-enriched solid electrolyte interface layer on lithium metal surface. As expected, the assembled Li||LiFePO4 cells deliver a high reversible discharge capacity of 139 mAh g-1 at 0.5 C and good cycling stability. Besides, the pouch cells exhibit a steady open-circuit voltage and can operate normally under abuse testing (fold, cut), showing its outstanding safety performance.

Self‐Assembled Molecule Doping Enables High‐Efficiency Hole‐Transport‐Layer‐Free Perovskite Light‐Emitting Diodes

AbstractHole‐transport‐layer‐free (HTL‐free) perovskite light‐emitting diodes (PeLEDs) are attracting increasing research attention because of their simplified device structure, fast preparation process, and high cost effectiveness. However, their much lower external quantum efficiency (EQE) as compared with the conventional p‐i‐n type ones has considerably limited their application prospects. Here, a self‐assembled molecule (SAM) doping strategy is proposed by introducing [4‐(3,6‐dimethyl‐9H‐carbazol‐9‐yl) butyl] phosphonic acid (Me‐4PACz) containing PO functional groups into the perovskite precursor solution and preparing the HTL‐free quasi‐2D perovskite films through the one‐step spin‐coating process. The doped Me‐4PACz molecules can not only accumulate at the ITO/perovskite interface to lower the hole injection barrier, but also extend deep into the perovskite layer to suppress the trap density in perovskite films and regulate the crystallization process for monodispersed phase composition. With the further addition of ethoxylated trimethylolpropane triacrylate small molecule containing CO groups to passivate the defects synergistically with Me‐4PACz, the EQE of the corresponding device is boosted from 1.5% to 16.7% together with a 3.5‐fold increase in operational stability, which is the highest efficiency reported so far for HTL‐free PeLEDs. The results demonstrate that the SAM doping strategy can be a viable and facile way to prepare high‐performance HTL‐free PeLEDs for practical applications.

2D VOPO4 Pseudocapacitive Ultrafast‐Charging Cathode with Multi‐Electron Chemistry for High‐Energy and High‐Power Solid‐State Lithium Metal Batteries

AbstractLithium metal batteries (LMBs) are acknowledged to be one major direction for next‐generation energy storage devices. However, the practical applications of LMBs are certainly limited by the low power density and safety issues owing to the lack of high‐capacity pseudocapacitive cathode materials and solid electrolytes. Herein, the rational synthesis of 2D VOPO4 nanosheets with enriched V4+ defects (VOPO4@G‐Air) enabling ultrafast multi‐electron reactions as a high‐capacity pseudocapacitive cathode is reported. Through V4+ defect engineering, the larger polarizationand inhomogeneous multi‐electron reactions are vastly improved, resulting in remarkably fast kinetics. Benefiting from the ultrathin 2D structure and controllably regulated V4+ defect concentration, a high discharge capacity of 313 mA h g−1at 0.1C is achieved, anda large capacity of 116 mA h g−1 is offered at 50C. Finally, utilizing the as‐synthesized VOPO4@G‐Air and a solid‐state electrolyte based on ethoxylated trimethylolpropane triacrylate (ETPTA‐LiClO4‐SSE) , the assembled solid‐state LMBs (Li||ETPTA‐LiClO4‐SSE||VOPO4) show high energy density of 85.4 Wh kg−1 at 114.5 W kg−1 and high power density of 2.3 kW kg−1 at 45.86 Wh kg−1. Further, the pouch cell unveils extraordinary safety and excellent flexibility. This work provides new insights in the construction of ultrafast and high‐capacity pseudocapacitive cathodes with multi‐electron reactions for solid‐state LMBs.

High-performance, printable quasi-solid-state electrolytes toward all 3D direct ink writing of shape-versatile Li-ion batteries

The era of miniaturized and customized electronics requires scalable energy storage devices with versatile shapes. From the perspective of manufacturing, direct ink writing (DIW)-based 3D printing has attracted unprecedented interest, paving the way to demonstrate micro-batteries with design freedom and outstanding performance. Despite demands for all-printed Li-ion batteries with maskless processing, most of the efforts have been dedicated to developing printable active electrodes or building the 3D architecture, remaining challenges in both manufacturing and printable materials toward form-free, all 3D DIW printed Li-ion batteries. Herein, we present all 3D DIW printed, scalable shape versatile Li-ion batteries (ADP-LIBs) with high-performance, printable gel polymer electrolytes (GPEs). The rheological optimization of DIW printable inks for solid-state current collectors, electrodes, electrolytes, and packaging enables us to demonstrate well-defined shape-versatile ADP-LIBs with reliable extrusion. In particular, UV-curable polydimethylsiloxane (PDMS) and ethoxylated trimethylolpropane triacrylate (ETPTA) monomers provide thixotropic fluid behaviors and a mechanical framework in the quasi-solid-state electrolytes, respectively, which results in high-throughput and mechanically robust printed electrolyte layers. Our ADP-LIBs demonstrate a great deal of promise as a realistic solution for powering the target applications on-demand with aesthetic versatility, free-form factors, and competitive electrochemical performance.

12 µm‐Thick Sintered Garnet Ceramic Skeleton Enabling High‐Energy‐Density Solid‐State Lithium Metal Batteries

AbstractUltrathin composite solid‐state electrolytes (CSSEs) demonstrate great promise in high‐energy‐density solid‐state batteries due to their ultrathin thickness and good adaptability to lithium metal anodes. However, uncontrolled dendrite growth and performance deterioration caused by the aggregation of inorganic powder restrict the practical application of ultrathin CSSEs. Herein, a flexible, self‐supporting Li6.5La3Zr1.5Ta0.5O12 (LLZO) ceramic skeleton is prepared by the tape‐casting method. Subsequently, a 12 µm‐thick CSSE with a 3D interconnection structure is achieved through in situ UV curing of ethoxylated trimethylolpropane triacrylate (ETPTA) in a ceramic skeleton (CS‐CSSE). This design includes a sintered LLZO ceramic, which can avoid the uneven distribution of the inorganic phase and regulate ion migration. Meanwhile, the cross‐linked ETPTA polymer electrolyte contributes to lower interfacial impedance. In addition, the continuous two‐phase interface can also provide a fast transmission channel for Li+. As a result, CS‐CSSE demonstrates superior Li+ transference number (0.83) and ionic conductivity (1.19 × 10‐3 S cm‐1) at 25 °C. As‐prepared Li|LiNi0.83Co0.12Mn0.05O2 batteries exhibit high discharge specific capacities of 185.4 mAh g‐1 at 0.1 C and average coulombic efficiency greater than 99%. The pouch cells exhibit high energy densities of 376 Wh Kg‐1 and 1186 Wh L‐1. This work provides new insights into the application of ceramics to high‐energy‐density solid‐state batteries.

Magnetic core-shell microparticles for oil removing with thermal driving regeneration property

Here, we report the construction of magnetic core-shell microparticles for oil removal with thermal driving regeneration property. Water-in-oil-in water (W/O/W) emulsions from microfluidics are used as templates to prepare core-shell microparticles with magnetic holed poly (ethoxylated trimethylolpropane triacrylate) (PETPTA) shells each containing a thermal-sensitive poly (N-Isopropylacrylamide) (PNIPAM) core. The microparticles could adsorb oil from water due to the special structure and be collected with a magnetic field. Then, the oil-filled microparticles would be regenerated by thermal stimulus, in which the inner PNIPAM microgels work as thermal-sensitive pistons to force out the adsorbed oil. At the same time, the adsorbed oil would be recycled by distillation. Furthermore, the adsorption capacity of the microparticles for oil keeps very stable after 1st cycle. The adsorption and regeneration performances of the microparticles are greatly affected by the size of the holes on the outer PETPTA shells, which could be precisely controlled by regulating the interfacial forces in W/O/W emulsion templates. The optimized core-shell microparticles show excellent oil adsorption and thermal driving regeneration performances nearly without secondary pollution, and would be a reliable green adsorption material for kinds of oil.

High-Performance and Highly Safe Solvate Ionic Liquid-Based Gel Polymer Electrolyte by Rapid UV-Curing for Lithium-Ion Batteries.

Utilizing ionic liquids (ILs) with low flammability as the precursor component for a gel polymer electrolyte is a smart strategy out of safety concerns. Solvate ionic liquids (SILs) consist of equimolar lithium bis(trifluoromethylsulfonyl)imide and tetraglyme, alleviating the main problems of high viscosity and low Li+ conductivity of conventional ILs. In this study, within a very short time of 30 s, a SIL turns immobile using efficient and controllable UV-curing with an ethoxylated trimethylolpropane triacrylate (ETPTA) network, forming a homogeneous SIL-based gel polymer electrolyte (SGPE) with enhanced thermal stability (216 °C), robust mechanical strength (compression modulus: 1.701 MPa), and high ionic conductivity (0.63 mS cm-1 at room temperature). A Li|SGPE|LiFePO4 cell demonstrates high charge/discharge reversibility and cycling stability with a capacity retention rate of 99.7% after 750 cycles and an average Coulombic efficiency of 99.7%, owing to its excellent electrochemical compatibility with Li-metal. A close-contact electrode/electrolyte interface is formed by in situ curing of the electrolyte on the electrode surface, which enables the pouch full cell to work stably under the conditions of cutting/bending. In view of the excellent mechanical, thermal, and electrochemical performances of SGPE, it is believed to be a promising gel polymer electrolyte for constructing high-safety lithium-ion batteries (LIBs).

An acrylate-based quasi-solid polymer electrolyte incorporating a novel dinitrile poly(ethylene glycol) plasticizer for lithium-ion batteries

The performance of solid polymer electrolytes is characterized by lower ionic conductivity than conventional liquid electrolytes but provides advantages in terms of operational safety. A quasi-solid polymer electrolyte (QSPE) based on a new plasticizer 4,7,10,13-tetraoxahexadecane-1,16-dinitrile (bCN-PEG4) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) incorporated into a polyacrylates matrix was successfully prepared via UV-induced copolymerization. The matrix consists of units of trimethylolpropane ethoxylate triacrylate (ETPTA), poly(ethylene glycol) diacrylate (PEGDA), and the monoacrylate poly(ethylene glycol) methyl ether acrylate (mPEGa). The QSPE containing 55 wt% bCN-PEG4 exhibits highly uniform morphology, thermal stability > 200 °C, ionic conductivity of 1.8 × 10−4 S cm−1 at 30 °C, and 1.3 × 10−3 S cm−1 at 80 °C, coupled with very high electrochemical stability (> 5 V vs. Li/Li+) and a low glass transition temperature (− 55.7 °C). A cycling experiment in a Li/QPSE/Li cell setup demonstrated the compatibility toward lithium metal additionally. The bCN-PEG4 offers an overall satisfying performance as a plasticizer in a poly(ethylene oxide)-based solid polymer electrolyte. The new QSPE is an alternative to dinitrile-based (e.g., succinonitrile) or glycol ether-based (e.g., tetraglyme) plasticizers with application potential in high-voltage lithium-ion batteries.Graphical abstract

Towards visual color display with fast electric field response: Highly chromatic and stable colloidal photonic crystal inks

There is an increasing demand towards reflective color display devices with high contrast as well as eye-protection function. To this point, colloidal photonic crystal inks have attracted intensive attentions in terms of their unique abilities to enable vivid color variation upon external stimuli. In this paper, the SiO2-propylene carbonate (PC)-trimethylolpropane ethoxylate triacrylate (ETPTA)-based resins e-ink has been developed to construct photonic crystal photomodulation devices, which can realize electrophoresis-driven modification of structural color. Specifically, it is found that the addition of reduced graphene oxide (rGO) plays a key role in improving coloration, ink rheology and electrochromic response time simultaneously for its special optical and electrical properties. This work may be helpful for the design of e-inks aiming at reflective displays.

Shape memory photonic gels enable reversible regulation of photoluminescence: Towards multiple anti-counterfeiting

Rampant counterfeit products have seriously threatened worldwide public security. It is highly desirable yet challenging to develop advanced encryption and anti-counterfeiting strategies. Herein, a fluorophore-doped shape memory photonic gel (SMPG) for high-end multi-mode anti-counterfeiting purposes is developed by synergistically utilizing two collaborative optical signals of structural color and photoluminescence (PL). The SMPG is prepared by polymerizing mixed monomers of poly(ethylene glycol) methacrylate (PEGMA) and trimethylolpropane ethoxylate triacrylate (ETPTA) in the presence of self-assembled silica nanoparticles (NPs) array, followed by doping Rhodamine B (RhB) in the polymeric matrix and selectively etching the silica NPs. The regular macroporous structures of RhB-doped SMPG can be destroyed temporarily after drying and restored after solvent triggering, and such a variation is reversible, repeatable, and stable. We show that dry RhB-doped SMPG is highly transparent under natural light and exhibits PL under UV light, while wet RhB-doped SMPG exhibits vivid and angle-dependent structural color under natural light and a depressed PL under UV light because of the inhibition of the appearance of photonic bandgap (PBG). As a proof-of-concept, various shapes of anti-counterfeiting tags can be prepared by laser engraving technology, significantly improving the security of anti-counterfeiting tags and shows great potential in the high-end anti-counterfeiting fields.

Triplet‐Triplet Annihilation Up‐Conversion Luminescent Assisted Free‐Radical Reactions of Polymers Using Visible Light

AbstractDue to low penetration ability of ultraviolet (UV) light, UV‐induced free radical reactions of polymers are limited to the preparation of thin‐layer materials such as coatings and inks. Although upconversion (UC) nanomaterials that can be excited by near‐infrared (NIR) light and emit UV light which is used to achieve polymerization or curing of monomers or prepolymers, low quantum efficiency and high excitation threshold limit their applications. Here, triplet‐triplet annihilation up‐conversion luminescent (TTA‐UCL) chromophores of platinum (II) octaethylporphyrin (PtOEP) and 9,10‐diphenylanthracene (DPA) are used to realize TTA‐UCL‐assisted photoinitiated polymerization of butyl acrylate (BA) and ethoxylated trimethylolpropane triacrylate (ETPTA) as well as photo curing of polyurethane acrylates (PUA) using visible light at 520 nm. The effects of chromophores concentrations and incident light power density on double‐bond conversion rate are investigated. The results show that a mediate TTA‐UCL chromophore concentration of 0.02% is beneficial for polymerization of ETPTA‐co‐BA with thickness of 25 mm within 15 min. Satisfied adhesion of colored plastic substrates using PUA prepolymers can be achieved after irradiation for 30 s when chromophore concentration of 0.1% is used. TTA‐UCL assisted photoinitiated reactions show great potential in engineering aspects including quick repair of leaking tubes and photocuring of adhesives underwater.

In Situ Cross‐Linked Plastic Crystal Electrolytes for Wide‐Temperature and High‐Energy‐Density Lithium Metal Batteries

AbstractThe development of high‐energy‐density lithium metal batteries has been significantly hampered mainly due to the poor electrolyte–electrode compatibility, narrow operating temperature range, and stringent safety concerns of conventional electrolytes. Here, an in situ cross‐linked plastic crystal‐based electrolyte (CPCE) with an optimized composition design is proposed. Based on the interaction of succinonitrile (SN) and ethoxylated trimethylolpropane triacrylate (ETPTA) with polar carbonyl groups, CPCE delivers well‐tuned energy levels and a concentrated coordination structure, leading to an improved electrochemical window and stable electrode–electrolyte interface. In addition, the crystallization of SN molecules is also inhibited, ensuring suitable ion migration in bulky CPCE over a wide temperature range. Moreover, both the nonleakage of cross‐linked ETPTA and the nonflammability of the plastic crystal electrolyte (PCE) further reinforce the safety of CPCE. As a result, the well‐designed CPCE achieves high ion conductivity with a wide electrochemical window (≈5.4 V vs Li+/Li) and a broad operating temperature range (−20 to 100 °C). It also delivers dendrite‐free lithium plating with high Coulombic efficiency of up to ≈99.1%. The Cu|CPCE|LiNi0.8Co0.1Mn0.1O2 anode‐free pouch cell exhibits high energy density (≈1520 Wh L‐1) and high safety during abuse tests. This study paves a new pathway to realize the practical application of high‐energy‐density lithium metal battery energy storage systems.

Mechanically and operationally stable flexible inverted perovskite solar cells with 20.32% efficiency by a simple oligomer cross-linking method

Due to their great potential in wearable and portable electronics, flexible perovskite solar cells (FPSCs) have been extensively studied. The major challenges in the practical applications of FPSCs are efficiency, operational stability, and mechanical stability. Herein, we developed a facile approach by incorporating a cross-linking oligomer of trimethylolpropane ethoxylate triacrylate (TET) into perovskite films to simultaneously enhance the power conversion efficiency (PCE) and stability of FPSCs. A PCE of 20.32% was achieved, which are among the best results for the inverted FPSCs. Both mechanical and environmental stabilities were improved for the TET-incorporated FPSCs. In particular, the PCE retained approximately 87% of its initial value after 20,000 bending cycles at a radius of 4 mm. The inverted FPSCs retained 85% of the initial PCE after 500 h storage at 85 °C and 90% after 900 h continuous one-sun illumination. A joint experiment–theory analysis ascribed the underlying mechanism to the reduced defect densities, improved crystallinity, and stability of the perovskite absorbers on flexible substrates caused by TET incorporation.

Stability enhancement of perovskite solar cells via multi-point ultraviolet-curing-based protection

As efficiency approaches the limit, it becomes more urgent to solve the toxicity and instability of organometal halide perovskite solar cells (PSCs), which asks for enhancement by applying methods that majorly contribute to stability itself to help prevent device from suffering from harmful matters. In this paper, we introduce a simple ultraviolet (UV) curing recipe which contains ethoxylated trimethylolpropane triacrylate (ETPTA) and 2-hydroxy-2-methyl-1-phenyl-1-propanone. ETPTA is polymerized by UV-curing and is applied as additive rather than as encapsulation material to distribute around the perovskite as a cross-linked network. Suitable amount of UV-gel added in perovskite precursor solution and hole transport material solution during device fabrication could promotes the crystallization of perovskite, reduce the diffusion of moisture in hole transport layer and therefore avoid degradation of PSCs. Notable protection happens with a volume percentage of ETPTA no more than 0.5%, especially in ambient conditions with humidity larger than 60%. • UV-gel is introduced through fabrication process and polymerized by UV-curing. • The addition of UV-gel is beneficial to the crystallization of perovskite. • Polymerized UV-gel effectively prevents the degradation of perovskite and device.

Effect of UV light polymerization time on the properties of plastic crystal composite polyacrylate polymer electrolyte for all solid‐state lithium‐ion batteries

AbstractTo solve the issues of low ionic conductivity, poor interfacial stability, and weak mechanical strength in the current polymer electrolytes, herein, the UV curing method is proposed to in‐situ polymerize the plastic crystal composite solid polymer electrolyte (S‐PCCE). By using ethoxylated trimethylolpropane triacrylate (ETPTA) as polymerization monomer, in conjunction with the butadiene nitrile and other additives, the S‐PCCE is prepared under ultraviolet light. The S‐PCCE shows improved ionic conductivity than other solid electrolyte materials. The ionic conductivity at room temperature can reach 0.98 × 10−3 S/cm, and it can reach 2.8 × 10−3 S/cm at 55°C, which is beneficial to achieve high battery performance. The LiFePO4/S‐PCCE/Li battery has a high initial discharge specific capacity of 150.4 mAh/g at 0.2C, and the highest discharge specific capacity can reach 162.5 mAh/g. Moreover, after 100 cycles, the battery can still maintain a high discharge specific capacity of 154.2 mAh/g, with a Coulomb efficiency of 98.4%. At the same time, the electrolyte has excellent high‐temperature adaptability, and can still work stably at 55°C with improved ionic conductivity. The superior performance of this material indicates that the plastic crystal composite polyacrylate solid electrolyte based on UV curing method can be used to prepare a high‐performance lithium‐ion battery, and this technology can also be compatible with existing lithium‐ion battery equipment.