Open Access Research Article Issue
Enhanced cathodic activity by tantalum inclusion at B-site of La0.6Sr0.4Co0.4Fe0.6O3 based on structural property tailored via camphor-assisted solid-state reaction
Journal of Advanced Ceramics 2022, 11 (8): 1330-1342
Published: 13 July 2022

Lanthanum strontium cobalt ferrite (LSCF) is an appreciable cathode material for solid oxide fuel cells (SOFCs), and it has been widely investigated, owing to its excellent thermal and chemical stability. However, its poor oxygen reduction reaction (ORR) activity, particularly at a temperature of ≤ 800 ℃, causes setbacks in achieving a peak power density of > 1.0 W·cm-2, limiting its application in the commercialization of SOFCs. To improve the ORR of LSCF, doping strategies have been found useful. Herein, the porous tantalum-doped LSCF materials (La0.6Sr0.4Co0.4Fe0.57Ta0.03O3 (LSCFT-0), La0.6Sr0.4Co0.4Fe0.54Ta0.06O3, and La0.6Sr0.4Co0.4Fe0.5Ta0.1O3) are prepared via camphor-assisted solid-state reaction (CSSR). The LSCFT-0 material exhibits promising ORR with area-specific resistance (ASR) of 1.260, 0.580, 0.260, 0.100, and 0.06 Ω·cm2 at 600, 650, 700, 750, and 800 ℃, respectively. The performance is about 2 times higher than that of undoped La0.6Sr0.4Co0.4Fe0.6O3 with the ASR of 2.515, 1.191, 0.596, 0.320, and 0.181 Ω·cm2 from the lowest to the highest temperature. Through material characterization, it was found that the incorporated Ta occupied the B-site of the material, leading to the enhancement of the ORR activity. With the use of LSCFT-0 as the cathode material for anode-supported single-cell, the power density of > 1.0 W·cm-2 was obtained at a temperature < 800 ℃. The results indicate that the CSSR-derived LSCFT is a promising cathode material for SOFCs.

Open Access Review Issue
Advances in 3D printing of magnetic materials: Fabrication, properties, and their applications
Journal of Advanced Ceramics 2022, 11 (5): 665-701
Published: 20 April 2022

Magnetic materials are of increasing importance for many essential applications due to their unique magnetic properties. However, due to the limited fabrication ability, magnetic materials are restricted by simple geometric shapes. Three-dimensional (3D) printing is a highly versatile technique that can be utilized for constructing magnetic materials. The shape flexibility of magnets unleashes opportunities for magnetic composites with reducing post-manufacturing costs, motivating the review on 3D printing of magnetic materials. This paper focuses on recent achievements of magnetic materials using 3D printing technologies, followed by the characterization of their magnetic properties, which are further enhanced by modification. Interestingly, the corresponding properties depend on the intrinsic nature of starting materials, 3D printing processing parameters, and the optimized structural design. More emphasis is placed on the functional applications of 3D-printed magnetic materials in different fields. Lastly, the current challenges and future opportunities are also addressed.

Open Access Research Article Issue
Novel 3D grid porous Li4Ti5O12 thick electrodes fabricated by 3D printing for high performance lithium-ion batteries
Journal of Advanced Ceramics 2022, 11 (2): 295-307
Published: 11 January 2022

Three-dimensional (3D) grid porous electrodes introduce vertically aligned pores as a convenient path for the transport of lithium-ions (Li-ions), thereby reducing the total transport distance of Li-ions and improving the reaction kinetics. Although there have been other studies focusing on 3D electrodes fabricated by 3D printing, there still exists a gap between electrode design and their electrochemical performance. In this study, we try to bridge this gap through a comprehensive investigation on the effects of various electrode parameters including the electrode porosity, active material particle diameter, electrode electronic conductivity, electrode thickness, line width, and pore size on the electrochemical performance. Both numerical simulations and experimental investigations are conducted to systematically examine these effects. 3D grid porous Li4Ti5O12 (LTO) thick electrodes are fabricated by low temperature direct writing technology and the electrodes with the thickness of 1085 μm and areal mass loading of 39.44 mg·cm-2 are obtained. The electrodes display impressive electrochemical performance with the areal capacity of 5.88 mAh·cm-2@1.0 C, areal energy density of 28.95 J·cm-2@1.0 C, and areal power density of 8.04 mW·cm-2@1.0 C. This study can provide design guidelines for obtaining 3D grid porous electrodes with superior electrochemical performance.

Open Access Review Issue
Photopolymerization-based additive manufacturing of ceramics: A systematic review
Journal of Advanced Ceramics 2021, 10 (3): 442-471
Published: 27 March 2021

Conversion of inorganic–organic frameworks (ceramic precursors and ceramic–polymer mixtures) into solid mass ceramic structures based on photopolymerization process is currently receiving plentiful attention in the field of additive manufacturing (3D printing). Various techniques (e.g., stereolithography, digital light processing, and two-photon polymerization) that are compatible with this strategy have so far been widely investigated. This is due to their cost-viability, flexibility, and ability to design and manufacture complex geometric structures. Different platforms related to these techniques have been developed too, in order to meet up with modern technology demand. Most relevant to this review are the challenges faced by the researchers in using these 3D printing techniques for the fabrication of ceramic structures. These challenges often range from shape shrinkage, mass loss, poor densification, cracking, weak mechanical performance to undesirable surface roughness of the final ceramic structures. This is due to the brittle nature of ceramic materials. Based on the summary and discussion on the current progress of material–technique correlation available, here we show the significance of material composition and printing processes in addressing these challenges. The use of appropriate solid loading, solvent, and preceramic polymers in forming slurries is suggested as steps in the right direction. Techniques are indicated as another factor playing vital roles and their selection and development are suggested as plausible ways to remove these barriers.

Open Access Research Article Issue
Additive manufacturing of thin electrolyte layers via inkjet printing of highly-stable ceramic inks
Journal of Advanced Ceramics 2021, 10 (2): 279-290
Published: 10 February 2021

Inkjet printing is a promising alternative for the fabrication of thin film components for solid oxide fuel cells (SOFCs) due to its contactless, mask free, and controllable printing process. In order to obtain satisfying electrolyte thin layer structures in anode-supported SOFCs, the preparation of suitable electrolyte ceramic inks is a key. At present, such a kind of 8 mol% Y2O3-stabilized ZrO2 (8YSZ) electrolyte ceramic ink with long-term stability and high solid loading (> 15 wt%) seems rare for precise inkjet printing, and a number of characterization and performance aspects of the inks, such as homogeneity, viscosity, and printability, should be studied. In this study, 8YSZ ceramic inks of varied compositions were developed for inkjet printing of SOFC ceramic electrolyte layers. The dispersing effect of two types of dispersants, i.e., polyacrylic acid ammonium (PAANH4) and polyacrylic acid (PAA), were compared. The results show that ultrasonic dispersion treatment can help effectively disperse the ceramic particles in the inks. PAANH4 has a better dispersion effect for the inks developed in this study. The inks show excellent printable performance in the actual printing process. The stability of the ink can be maintained for a storage period of over 30 days with the help of initial ultrasonic dispersion. Finally, micron-size thin 8YSZ electrolyte films were successfully fabricated through inkjet printing and sintering, based on the as-developed high solid loading 8YSZ inks (20 wt%). The films show fully dense and intact structural morphology and smooth interfacial bonding, offering an improved structural quality of electrolyte for enhanced SOFC performance.

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