Tape Casting Method Research Articles

Superior energy storage performance in antiferroelectric multilayer ceramics via heterogeneous interface structure engineering

Dielectric ceramics are desired for pulse power electronic systems owing to their high power density. However, there are obstacles in the simultaneous enhancement of energy density (Wrec) and energy efficiency (ƞ). The two crucial parameters affecting the energy storage performance are polarization (P) and electric breakdown strength (Eb). Although considerable efforts have been made, the contradiction between high P and high Eb is still a challenging problem. In this work, the macroscopic properties and microstructure of (Pb0.9Ba0.04La0.04)(Zr0.65Sn0.3Ti0.05)O3 (PBLZST) / (Pb0.95Ca0.02La0.02)(Zr0.93Sn0.05Ti0.02)O3 (PCLZST) antiferroelectric multilayer ceramics prepared by a tape-casting method are combined to realize the synergic optimization of P and Eb. The huge difference in dielectric constants (εr) of these two materials leads to the interfacial polarization effect and interfacial blocking effect. Despite their different electric characteristics, they have similar elemental compositions, matching lattice structures and compatible sintering processability, forming dense interface bonding. Ultimately, the structured ceramics achieve a high Wrec of 9.4 J cm−3 and a high ƞ of 86.5 % at 278 kV cm−1, as well as favorable temperature stability, frequency stability and anti-fatigue property. The structure design combined with interfacial effects in this study provides a new strategy for the preparation of multilayer ceramics with superior energy storage performance.

Fe-complex modified cellulose acetate composite membrane with excellent photo-Fenton catalytic activity

A novel Fe-complex loaded visible-light active cellulose acetate (CA) composite membrane (Fe-complex/CA) was fabricated using the tape casting method. The Fe-complex was structurally characterized by single-crystal X-ray diffraction, and the prepared composite membrane was characterized by SEM, XPS, XRD, FTIR and UV–Vis diffuse reflectance spectroscopy. The Fe-complex/CA composite membrane exhibited relatively good visible light photocatalytic activity toward organic dyes and sulfadiazine antibiotics in the presence of low concentrations of H2O2. After irradiation for 60 min, the degradation efficiencies of basic fuchsin, methylene blue and sulfadiazine reached 100 %, 93.4 % and 95.7 %, respectively. The composite membrane maintained good photocatalytic activity after four catalytic cycles. Kinetic studies showed that the degradation processes of basic fuchsin, methylene blue and sulfadiazine were all in accordance with first-order reaction kinetics. In addition, the photocatalytic mechanism of the Fe-complex/CA composite membrane in the photo-Fenton reaction was also discussed in detail.

Self-supported cobalt/cobalt selenide heterojunction for highly efficient overall water splitting

Electrocatalytic water splitting is a vastly reliable method for hydrogen production. Nonetheless, its wide practical application urgently requires the development of highly active and stable bifunctional electrocatalysts with self-supported structures. This paper reports on a novel, simple way to fabricate an efficient cobalt/cobalt selenide (CS) catalytic electrode with a unique 3-D finger-like structure. More specifically, porous Co substrate was fabricated by a phase-inversion tape-casting and sintering method, followed by one-step selenization in Ar atmosphere. The resultant CS electrode manifested superior catalytic performance in both HER and OER (hydrogen and oxygen evolution reaction, respectively) that took place in an alkaline medium, with low overpotential and high long-term stability. Furthermore, the electrolysis test for overall water splitting was successfully performed by assembling the CS electrodes as both anode and cathode. The excellent electrocatalytic performance is ascribed to the high conductivity of the Co substrate, the distinctive finger-like structure, and the numerous in-situ developed heterojunctions, which suitably adjust the electronic structure and decrease the energy barrier of water splitting. Moreover, the density function theory (DFT) calculations revealed that the heterojunction enhances the density of the state near the Fermi level and optimize the kinetics of HER and OER processes. As a result, the hydrogen adsorption free energy (ΔGH*) is close to zero, and the energy barrier of the rate-determining step of OER is low due to the heterojunction formed.

Novel Fabrication Processing of Porous Al2O3/CaAl12O19 Membrane by Combining Emulsion, Cement Curing and Tape-Casting Methods.

This paper presented an innovative method for fabrication of a porous Al2O3/CaAl12O19 ceramic membrane by combining emulsion method, cement curing and tape-casting technologies. The ceramic membrane featured a smooth surface and a porous internal structure. By adjusting the oil–water volume ratio from 1:1 to 4:1, the porosity of the samples increases from 45.6 to 67.3%, density decreases from 2.07 to 1.32 g/cm3 and bending strength decreases from 64.3 ± 1.2 to 31.7 ± 0.6 MPa. More significantly, the membranes showed great gas permeability (1.2 × 107–2.3 × 107 Lm−2 h−1 bar−1), opening up a wide range of applications in the field of gas filtration processes.

Proton-conducting membranes based on CsH2PO4 and copolymer of tetrafluoroethylene with vinylidene fluoride

In this work, proton conductivity, morphology and mechanical properties of (1–x)CsH2PO4–xF-42 (x=0.05–0.3, weight ratio) membranes were investigated for the first time. Thin flexible membranes for x≥0.15 with the uniform distribution of the components were obtained by a tape casting method. Mechanical properties of the membranes were measured by Vickers microhardness tests for a low polymer content (x˂0.15), also the tensile strength for membranes with high polymer content x=0.2–0.3 were evaluated. Proton conductivity of the (1–x)CsH2PO4–xpF-42 composite polymer electrolytes decreases monotonically with increasing x due to the effect of a «conductor-insulator» percolation. The combination of conductivity, mechanical strength and hydrophobic properties of (1–x)CsH2PO4–xF-42 makes certain compositions of proton-conducting membranes (x~0.2–0.25) promising for their use in intermediate-temperature fuel cells, despite decreased conductivity.

Argyrodite Solid Electrolyte-Integrated Ni-Rich Oxide Cathode with Enhanced Interfacial Compatibility for All-Solid-State Lithium Batteries.

All-solid-state lithium batteries (ASSLBs) paired with an argyrodite sulfide solid electrolyte have become a candidate to take the world by storm for achieving high energy and safety. However, the undesirable interface design between a sulfide solid electrolyte and cathode is difficult to address its scalability production challenge. Particularly, the inferior interfacial contact between a sulfide solid electrolyte and cathode is an intractable obstacle for the large-scale commercial application of ASSLBs. Herein, an elaborately designed conformally in situ integration of a sulfide solid electrolyte onto a Ni-rich oxide cathode is proposed to overcome this issue through a facile tape casting method. In this unique integrated electrode structure, the sulfide solid electrolyte intimately makes contact with the Ni-rich oxide cathode, which significantly strengthens the solid-solid interfacial compatibility, as well as decreases the interfacial reaction resistances, thereby enabling rapid Li+ transportation and a stable interfacial structure. As a result, ASSLBs consisting of a sulfide solid electrolyte-integrated Ni-rich oxide cathode and Li anode exhibit high discharge capacity, excellent cyclic stability, and remarkable rate performance, which are superior to the cells with segregated structures composed of a Ni-rich oxide cathode, sulfide solid electrolyte, and Li anode. The features clearly indicate that the advanced interfacial contact between the cathode and solid electrolyte is responsible for ASSLBs with low polarization and fast reaction kinetics. Therefore, this work provides a rational proof-of-concept fabrication protocol for the reliable interfacial structure design of high-performance ASSLBs.

Thin Nasicon Sodium-Ions Solid State Electrolyte By Tape Casting Method

In recent years, sodium ion batteries have shown its potential to compliment lithium ion batteries, especially in stationary energy storage system. Additionally, all-solid-state battery is perceived as the holy-grail battery. While numerous research efforts have been devoted to the search of solid-state materials with high ionic conductivity, it is paramount to reduce the thickness of the electrolyte to achieve a high energy density. In this study, the NASICON electrolyte is prepared by tape casting method and its thickness is controlled by the scrapper height during casting. It is realised that the areal specific resistance of the electrolyte is proportional to the thickness of the electrolyte and the 60 μm thick electrolyte shows an extremely low resistance of 42.7 Ω cm2. More importantly, such process is highly repeatable for large-scale production of thin freestanding solid-state electrolyte, which can be used in conventional bulk battery, redox-flow batteries, or metal-air batteries.

Thin Films (FTO/BaTiO3/AgNPs) for Enhanced Piezo-Photocatalytic Degradation of Methylene Blue and Ciprofloxacin in Wastewater.

In this study, we investigate the ability of barium titanate/silver nanoparticles (BaTiO3/AgNPs) composites deposited on a fluorine-doped tin oxide (FTO) glass using tape-casting method to produce piezoelectric thin film (FTO/BaTiO3/AgNPs) for piezocatalytic, photocatalytic, and piezo-photocatalytic degradation of methylene blue (MB) and ciprofloxacin (CIP) in wastewater. The prepared piezoelectric materials (BaTiO3 and BaTiO3/AgNPs) were characterized using XRD, SEM, TEM, EDS, UV-DRS, TGA, PL, BET, EIS, and chronoamperometry. The UV-DRS showed the surface plasmon resonance (SPR) of Ag nanoparticles on the surface of BaTiO3 at a wavelength of 505 nm. The TEM images revealed the average Ag nanoparticle size deposited on the surface of BaTiO3 to be in the range of 10–15 nm. The chronoamperometry showed that the photoreduction of silver nanoparticles (AgNPs) onto BaTiO3 (BTO) resulted in a piezo-electrochemical current enhancement from 0.24 to 0.38 mA. The composites (FTO/BaTiO3/AgNPs) achieved a higher degradation of MB and CIP when the photocatalysis and piezocatalysis processes were merged. Under both ultrasonic vibration and UV light exposure, FTO/BTO/AgNPs degraded about 72 and 98% of CIP and MB from wastewater, respectively. These piezoelectric thin films were shown to be efficient and reusable even after five cycles, suggesting that they are highly stable. Furthermore, the reactive oxygen species studies demonstrated that hydroxyl radicals (·OH) were the most effective species during degradation of MB, with minor superoxide radicals (·O2–) and holes (h+). From this study, we were able to show that these materials can be used as multifunctional materials as they were able to degrade both the dye and pharmaceutical pollutants. Moreover, they were more efficient through the piezo-photocatalytic process.

Ultrasound-assisted preparation of chitosan/nano-silica aerogel/tea polyphenol biodegradable films: Physical and functional properties

In this study, chitosan(CS), nano-silicon aerogels(nSA) and tea polyphenols(TP) were used as film-forming materials and processed with ultrasonication to form films using the tape-casting method. The effects of ultrasonication time, temperature and frequency on the properties of CS/nSA/TP film were explored via material property testing. The results of response surface showed that the maximum tensile strength of the film was 4.036 MPa at ultrasonication time(57.97 min), temperature(37.26 °C) and frequency(30 kHz). The maximum elongation at break of the film was 279.42 % at ultrasonication time(60.88 min), temperature(39.93 °C) and frequency(30 kHz). Due to cavitation and super-mixing effects, ultrasonication may make the surface of the film smoother and easier to degrade. After ultrasonication, TPs were protected by the 3D network structure composed of CS and nSA. Ultrasonication improved the antioxidant and antibacterial properties of the film. These results show that ultrasonication is an effective method to improve the properties of films.

High performance poly(carbazolyl aryl piperidinium) anion exchange membranes for alkaline fuel cells

Anion exchange membrane fuel cells (AEMFCs) is a potential substitute to the prevailing proton exchange membrane fuel cells (PEMFCs), since non-precious metal catalysts can be applied in the AEMFCs, leading to much lower cost of it. However, anion exchange membranes (AEMs), as a crucial component of the AEMFCs, has always been a challenge in the commercialization of AEMFCs, such as poor life-time and conductivity. Herein, a series of poly(carbazolyl aryl piperidinium) AEMs and ionomers are prepared with non-rotatable rigid carbazole group next to piperidinium ring on the polymer backbone for the first time, and the membranes were fabricated by mass production method of tape-casting. The membranes exhibit extraordinary comprehensive performance, for instance, high hydroxide conductivity up to 204.8 mS cm−1 at 90 °C, good mechanical strength of >50 MPa in wet state, low hydrogen permeability and excellent alkaline stability of only 3% decline after 2100 h in 1 M KOH at 80 °C. Fuel cell (H2–O2) based on the as-prepared membranes and ionomers shows outstanding peak power density of 1.72 W cm−2 at a quite low back pressure of 20 kPa, and only 2.6% decay was observed after 120 h.

Effect of boron doping on energy storage performance of PLZST ceramics

In this paper, thick film antiferroelectric ceramics (1-x)(Pb0.97La0.02)(Zr0.46Sn0.48Ti0.06)O3-xH3BO3 ((1-x)PLZST-xH3BO3, x = 0–0.025) were prepared by solid state sintering and tape-casting method. The effects of boron-doping on the microstructure, dielectric properties and energy storage properties of (1-x)PLZST-xH3BO3 ceramics were investigated. Appropriate boron-doping can improve the stability of antiferroelectric phase, delay phase transition and increase saturation polarization strength. Compared with the undoped PLZST thick films, the maximum polarization intensity increased by 1.9 times and the residual polarization decreased by 37%. When x = 0.020, the maximum recoverable energy storage density is 2.74 J/cm3, and the energy storage efficiency is 88.12%.

A cathode-supported solid oxide fuel cell prepared by the phase-inversion tape casting and impregnating method

Cathode-supported Solid Oxide Fuel Cells (SOFCs) have unique advantages of stability and operating life, but the commercialization process is limited by manufacturing cost and poor electrochemical performance. In this paper, a cathode-supported SOFC with 3YSZ-LSM95| porous 8YSZ| dense 8YSZ| porous 8YSZ sandwich structure was successfully fabricated by phase-inversion tape casting and co-sintering method. The cathode support demonstrated finger shaped macropore with high porosity. The long-term stability of symmetric cells with and without impregnated LSC nanoparticals was evaluated and no obvious degregadion were observed. The peak power densities of single cell reached 464, 209, 271 and 144 mW cm−2 at 850, 800, 750 and 700 °C respectively when Ni nano-particles as the anode catalyst and LSC nano-particles as the cathode catalyst, showing a significant improvement in electrochemical performance compared with non-LSC cell. Additionally, the distribution of relaxation times (DRT) method was empoyed to analysis the polarization process at high-resolution, for better understanding the mechanism of electrochemical reaction of cells. The results indicated the impregnated LSC particles can increase the triple phase-boundaries (TPBs) for fast oxygen reduction reaction and improve the electrochemical performance. However, the optimization of anode and cathode are needed in the future work.

Fabrication of anti‐UV absorbing and antibacterial soybean protein isolate composite film modified with thyme and mangosteen peel extracts

AbstractIn order to reduce the threat of ‘plastic pollution’ and reduce or eliminate some traditional polymer packaging materials, in this study, soybean protein isolate (SPI) composite film, a biodegradable natural polymer film, was prepared by tape casting method with Thyme (Thy) and mangosteen peel extracts (MPE) as antibacterial agents. The antibacterial rates of the composite films against E. coli and S. aureus were 95.79% and 92.63%, respectively, and the DPPH free radical scavenging rate was 70.28%. The composite film had good UV–visible barrier properties. Compared with the pure SPI film, the tensile strength of the composite film was improved, the water absorption, water solubility, and water vapor permeability were reduced, and the contact angle was improved. The maximum thermal decomposition temperature of the composite film increased and the thermal stability increased. Fourier Transform Infrared Spectroscopy (FTIR) studies showed the polyphenol‐protein of the composite film was bound by hydrophobic interaction. X‐ray Photoelectron Spectroscopy (XPS) showed good interaction with the protein structure by adding antibacterial substances and their aromatic quinone structures. X‐ray Diffraction (XRD) studies showed that the crystallinity of the composite films increased. Therefore, the composite membrane in this study can be used to prepare high‐strength packaging materials with antibacterial functions.

Synthesis and Characterization of Gadolinium-Doped Zirconia as a Potential Electrolyte for Solid Oxide Fuel Cells

Zirconia-based composites with high thermochemical stability and electrochemical activity are the most promising solid electrolytes for manufacturing solid oxide fuel cells (SOFCs). In the present work, nanocrystalline composite powders of gadolinium-doped zirconia (GDZ: Gd2xZr2(1−x)O4−x) with various doping fractions (0.01 ≤ x ≤ 0.16) were synthesized by the Pechini method and applied for the fabrication of several electrolyte pellets to evaluate their physicochemical properties, sinterability, and conductivity. The X-ray diffraction (XRD) patterns and the thermogravimetry/differential thermal analysis (TGA/DTA) of the synthesized powders confirmed the successful formation of nanocrystalline GDZ in the tetragonal phase with complete substitution of gadolinium phase into the zirconia (ZrO2) lattice. The synthesized gadolinium zirconate powders were then shaped into pellet forms using the tape casting method, followed by sintering at 1300 °C (for 2.5 h). The microstructural analysis of the electrolyte pellets showed suitable grain boundary welding at the surface with an acceptable grain growth at the bulk of the T-phase GDZ samples. The impedance measurements indicated that the T-phase GDZ-8 could provide a comparably higher ionic conductivity (with 7.23 × 10−2 S/cm in the air at 800 °C) than the other dopant fractions. The results of this work can help better understand the characteristics and electrochemical performance of the T-phase gadolinium zirconate as a potential electrolyte for the fabrication of SOFCs.

Design of crack deflection induced high toughness laminated Si3N4 ceramics based on hollow oriented one-dimensional microstructure

A laminated silicon nitride (Si3N4) ceramic material with a hollow, oriented, one-dimensional microstructure was successfully prepared based on the tape casting and sacrificial template method. The results show that hollow, oriented, one-dimensional microstructures can effectively induce crack deflection. Different arrangements of the structural design layer and dense layer will have different effects on the material. In particular, bulks with a single-layer orthogonal arrangement of the structural design layer possess high toughness and obvious crack deflection during the fracture process. A kind of multiscale crack deflection mode was realized. Compared with the fracture toughness of the monolithic Si3N4 ceramic bulk (5.55 MPa m1/2), the fracture toughness can reach 8.73 MPa m1/2, and the flexural strength can still reach 391.47 MPa with only a slight decrease.

Engineering the wetting behavior of ceramic membrane by carbon nanotubes via a chemical vapor deposition technique

Hydrophobic membrane is widely applied for various applications due to its water repellent and self-cleaning properties. In this work, novel alumina/carbon nanotubes (Al2O3/CNTs) composite hydrophobic membranes are prepared in two steps: first, the membranes are fabricated via the phase inversion tape casting method, and then post-treated in a chemical vapor deposition (CVD) process to include CNTs into their structure. The addition of CNTs allows for controlling the contact angle of the membrane from 0 to 136°, creating highly hydrophobic. Moreover, a nitrogen permeability of 0.74±0.01 × 106 L m−2 h−1 bar−1 is achieved of the composite membrane, while its pure water flux is effectively decreased to 0, further indicating the good hydrophobicity. In addition, the hydrophobicity of the membrane can be maintained in the temperature range of 25–200 °C. It is demonstrated that the Al2O3/CNTs composite membrane is a promising hydrophobic membrane candidate for membrane separation application because of its good hydrophobicity, high thermal stability and considerable gas permeability, moreover, the wetting properties of ceramic membrane can be effectively engineered by adding CNTs into the membrane skeleton via the CVD technique.

The antibacterial activity and antibacterial mechanism of the tea polyphenol liposomes/lysozyme–chitosan gradual sustained release composite coating

SummaryTo obtain long‐lasting preservation materials, the tea polyphenol liposomes (TP‐Lips)/lysozyme (LZM)–chitosan (CS) composite coating with the gradual sustained property was prepared by tape casting method. These coatings were characterised, and their physicochemical properties were measured. Meanwhile, the antibacterial mechanisms of coatings were studied using the spoilage bacteria of aquatic products (Shewanella putrefaciens and Pseudomonas fluorescens) as target strains. Compared with CS coating, the incorporation of TP‐Lips makes the cracks and granular matter of the coatings increase. Except for the oxygen permeabilities (OP) and carbon dioxide permeabilities (CDP), the rest of the physicochemical properties are decreased, including tensile strength (Ts), elongation at break (EB) and light transmittance (T). Antibacterial mechanisms indicate that TP and LZM have a synergistic antibacterial effect. The slow‐release system composed of liposomes and coating prolongs the action time of TP and LZM. Hence, the TP‐Lips/LZM‐CS coating could be a hopeful material in food preservation field with excellent antibacterial properties.

Protonic ceramic cells with thin BaZr0.8Y0.2O3-δ electrolytes for stable separation of H2 from H2–CO2 mixtures

Here we report selective separation of high-purity H 2 from a CO 2 -containing stream using protonic ceramic cells with thick Ni–BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ cathode substrates, thin BaZr 0.8 Y 0.2 O 3-δ electrolytes and thin Ni–BaZr 0.8 Y 0.2 O 3-δ anodes, as fabricated by the tape casting and tape lamination methods. Scanning electron microscopy observations show an overall micron porous structure for both electrodes with some nano-scale porosities inside Ni particles. The measured H 2 flux out of 3%-humidified 10% H 2 – 90% CO 2 at 700°C was 3.2 ml•cm −2 •min −1 at 0.90 V with a Faraday's efficiency of 97.8%. A preliminary 50-hour measurement in 10% H 2 – 90% CO 2 shows a slight increase in the pumping voltage from 0.96 to 1.03 V with a constant H 2 flux of 6.5 ml•cm −2 •min −1 and Faraday's efficiencies continuously above 97%, as enabled by excellent stability of BZY against CO 2 . • Protonic ceramic cells with thin BaZr 0.8 Y 0.2 O 3-δ electrolytes are fabricated. • Ni–BaZr 0.8 Y 0.2 O 3-δ anodes show promise for stable operation in 10%H 2 –90%CO 2 . • The H 2 recovery rate from 10%H 2 –90%CO 2 is 3.2 ml•cm −2 •min −1 at 1.5 V.

Preparation and Characterization of Biodegradable κ-Carrageenan Based Anti-Bacterial Film Functionalized with Wells-Dawson Polyoxometalate.

In the present study, an anti-bacterial film (Carr/POM film) was prepared through the incorporation of Wells-Dawson polyoxometalate K6[Mo18O62P2] into κ-carrageenan-based polymers using the tape-casting method. The mechanical properties, thermal stability, and morphology of the prepared film were characterized. The obtained results showed that incorporation of K6[Mo18O62P2] significantly affected the morphology and structure of the films. Moreover, the polyoxometalate-based film demonstrated desirable bactericidal activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). Carr/POM (@8 mg/mL) film resulted in an obvious inhibition zone around the film in Kirby-Bauer disk diffusion test, which could also remove 99% of S. aureus and E. coli on plastic, glass, and stainless steel. In addition, this anti-bacterial film also demonstrated good biodegradability, which could be decomposed in soil in around 1 week. In conclusion, the polyoxometalate-based film showed good anti-bacterial property against food-borne pathogenic microbes, suggesting the prepared film has great potential to be developed as promising food packaging.

Effect of stress on the phase transition and optimizing electric-induced strain behavior of Bi0.5Na0.5TiO3-SrTiO3 lead-free co-fired multilayer piezoactuators

A series of (1-x)Bi1/2Na1/2TiO3-xSrTiO3+0.05 wt% MnO2 lead-free multilayer piezoactuators was prepared using a tape casting method, and the field-induced strain performance, temperature stability, electric fatigue and load characteristics were evaluated to assess potential practical applications. In contrast to traditional PZT ceramics, the fabrication of BNT bulk ceramics into multilayer piezoactuators provides significantly decreased strain (S)-electric field (E) characteristics as a result of internal compressive residual stress. The inactive edge distance, sintering temperature and layer thickness were all found to affect the compressive residual stress of the actuator. Through reconstructing the material composition and structure of BNT-ST actuators, active strain (0.168 %, 2 kV/mm), total strain (>0.15 %, E ≤ 2.5 kV/mm) and blocking stress (42.6 MPa) were realized in BNT-based cofired multilayer actuators, displaying a better performance than commercial PZT actuators. These results indicate that environmental-friendly BNT-based lead-free multilayer piezoactuators are promising candidates with regard to practical applications.