诸如固体氧化物燃料和电解池之类的基于电陶瓷的能源设备有望成为受益于使用3D打印技术开发创新概念的候选人，这些概念克服了现有制造技术的形状局限性。在2017年进行的一项类似项目的基础上，《材料化学杂志》发表了一项新研究，报告了使用陶瓷立体光刻技术制造一系列新型高性能SOEC（电解质支持的固体氧化物电池）的过程。用氧化钇稳定的氧化锆3D打印常规的平面和高纵横比的波纹状电解质，以制造固体氧化物电池。瓦楞纸设备在燃料电池和共电解模式下的性能提高了57％，与平面设备相比，其面积直接成比例。这种设计上的增强与印刷设备的经验证的耐用性（小于35 mV / 1000 h）相结合，代表了该领域的一种全新方法，并有望对下一代固体氧化物电池以及更广泛的固体电池产生巨大影响。状态能量转换或存储设备。
Electroceramic-based energy devices like solid oxide fuel and electrolysis cells are promising candidates to benefit from using 3D printing to develop innovative concepts that overcome shape limitations of currently existing manufacturing techniques. Building on a similar project conducted in 2017, a new study published by the Journal of Material Chemistry, reports on the fabrication a new family of highly performing SOECs – electrolyte-supported solid oxide cells – using ceramics stereolithography. Conventional planar and high-aspect-ratio corrugated electrolytes were 3D printed with yttria-stabilized zirconia to fabricate solid oxide cells. Corrugated devices presented an increase of 57% in their performance in fuel cell and co-electrolysis modes, which is directly proportional to the area enlargement compared to the planar counterparts. This enhancement by design combined to the proved durability of the printed devices (less than 35 mV/1000 h) represents a radically new approach in the field and anticipates a strong impact in future generations of solid oxide cells and, more generally, in any solid-state energy conversion or storage devices.
Solid oxide fuel cells (SOFCs) are zero-emission power generators able to convert hydrogen into electricity with efficiency (LHV) above 60% over the whole range of kilowatt scales. This efficiency can reach values as high as 90% (LHV) in combined heat and power units (CHP), with SOFCs being one of the most efficient energy generation devices currently existing. Alternatively, the same devices operated in reverse mode are energy storage units able to produce storable hydrogen from electricity and water. SOECs (solid oxide electrolysis cells) are highly efficient energy conversion devices, with higher production yields and lower specific electric energy than competing electrolysis technologies.
Solid oxide cells (SOCs) are ceramic-based multilayer electrochemical cells consisting of a gas-tight oxide-ionic conductor electrolyte with electrodes in both sides. The state of the art materials for SOCs are yttria-stabilized zirconia (YSZ) for the electrolyte, combined with YSZ-based composites as electrodes, namely, lanthanum strontium manganite (LSM-YSZ) for the oxygen electrode and Ni–YSZ for the fuel electrode.
Only few strategies have been explored to take advantage of a straightforward increase of the performance of the cells by modification of its geometry, likely due to the strict limitations in manufacturing complex ceramic shapes. For instance, an increase of the active area of the cells by corrugation of the electrolyte will directly reduce the internal resistance of the cell, i.e. its area-specific resistance, proportionally increasing their performance per projected area.
这项研究提出了通过具有波纹结构的SLA 3D打印制造250μm厚的8YSZ（8 mol％氧化钇稳定的氧化锆）电解质，与同样印刷的平面对应物相比，其本质上增加了约60％的有效面积。在这项工作中，在800-900°C的燃料电池温度范围以及CO2和蒸汽共电解模式下，对这两种类型电池的电化学性能进行了全面表征。细胞阻抗谱的分析可以清楚地识别增强的起源。瓦楞纸架构在此作为可打印几何形状的第一个示例进行讨论，可以通过这项工作中提出的陶瓷3D打印方法来制造瓦楞纸，证明了它在改善如此获得的电池性能方面的不公平优势。
This study presents the fabrication of 250 μm-thick 8YSZ (8 mol% yttria-stabilized zirconia) electrolytes by SLA 3D printing with a corrugated architecture, which intrinsically increases around 60% the active area compared to an also printed planar counterpart. A comprehensive characterization of the electrochemical performance of both types of cells is presented in this work in a range of temperatures between 800–900 °C in fuel cell and CO2and steam co-electrolysis modes. The analysis of the impedance spectroscopy of the cells allowed the clear identification of the origin of the enhancement. The corrugated architecture is discussed here as a first example of the wide range of printable geometries that can be fabricated by the ceramic 3D printing approach proposed in this work, proving its unfair advantage in improving the performance of the so obtained cell.
Planar and corrugated YSZ ceramic pieces were fabricated by using CERAMAKER a ceramic 3D printer from 3DCERAM. Computer Assisted Design (CAD) software was employed to sketch planar and corrugated membranes of the same 2.00 cm in diameter (of which 1.6 cm is the diameter for the electrode deposition, determining the future active area of the cell) and 250 μm in thickness but with different effective surface areas of 2.00 and 3.15 cm2, respectively. Such membranes were monolithically integrated with external annular rings to enhance the mechanical stability and ensure good sealing of the membranes during the testing.
为了在烧结后获得此处所述的尺寸，应采用重新缩放工艺，以考虑烧结过程中的收缩（出于清晰原因，未报告初始设计值）。通过使用DMC软件对设计进行切片并控制3D打印机，可以自动创建STL文件。使用由3DCERAM制成的3DMIX-8YSZ无溶剂紫外光固化浆料，该浆料由8YSZ陶瓷粉，丙烯酸酯紫外光固化单体，光引发剂和分散剂组成。用可光聚合的粘合剂替代溶剂可实现高陶瓷填充量，良好的均质性和较低的悬浮液粘度，可通过添加稀释剂进一步改善。33沉积了具有高陶瓷填充量（约50 vol％）的8YSZ浆料在30×30 cm2的印刷平台上通过双刮刀系统能够均匀地分散浆料。
To obtain the dimensions here described after the sintering, a rescaling process is applied to take into account the shrinkage during the sintering process (initial design values are not reported for clarity reasons). STL files were automatically created by using DMC software to slice the design and control the 3D printer. The 3DMIX-8YSZ solvent-free UV-photocurable slurry from 3DCERAM, which is composed by 8YSZ ceramic powder, acrylate UV curable monomer, photoinitiator and dispersant, was employed. The substitution of solvents by photo-polymerizable binders allows to achieve high ceramic loading, good homogeneity and a low viscosity of the suspension, which is further improved by adding diluents.33 8YSZ slurry with high ceramic loading (ca. 50 vol%) was deposited over a 30 × 30 cm2 printing platform by a double doctor blade system able to homogeneously spread the paste.
调节叶片以沉积厚度为25μm的薄层。在沉积可光固化浆料后，聚焦在建筑平台上的UV半导体激光器（功率约500 mW）会逐片地复制由CAD设计的图案，并使用镜面光栅以5000 mm s-1的速度旋转。在紫外线照射下，含有自由基和在紫外线区域具有活性的光引发剂34的可光固化浆料会在自由基光聚合过程后局部固化。
The blades were adjusted to deposit a thin layer of 25 μm in thickness. After deposition of the photocurable slurry, a UV semiconductor laser (power around 500 mW) focused at the building platform reproduces, slice by slice, the pattern designed by CAD using mirror rastering with a speed of 5000 mm s−1. Under UV exposure, the photocurable slurry, containing a monomer and a photoinitiator active in the UV region,34 locally solidifies following a free-radical photopolymerization process.
Images of the self-standing 3D printed 8YSZ membranes. Top view (a and b) and cross-section (c and d) of the planar and corrugated membranes, respectively. Detail of the cross-section by SEM for the planar (e) and corrugated (f) electrolytes showing (in the inset) the steps defined with the layer-by-layer 3D printing process.
使用先前优化的标准程序制造对称和完全电化学电池。将商用NiO–YSZ和LSM–YSZ浆料（美国燃料电池材料）涂在3D打印的YSZ片上，分别作为燃料和氧气电极。燃料电极和氧电极分别使用1400°C的附着温度3 h和1200°C的附着温度1 h。
Symmetrical and full electrochemical cells were fabricated using previously optimized standard procedures. Commercial NiO–YSZ and LSM–YSZ pastes (Fuel cell materials, USA) were painted on 3D printed YSZ pieces as fuel and oxygen electrodes, respectively. Attachment temperatures of 1400 °C for 3 h and 1200 °C for 1 h were employed for the fuel and oxygen electrodes, respectively.
高温烧结后，通过SLA 3D打印制造了平面波纹状8YSZ独立式膜，从而获得了无裂纹且均匀的零件。总体而言，3D打印的YSZ零件被认为适合在SOFC / SOEC应用中用作电解质。平面和波纹状LSM-YSZ / YSZ / Ni-YSZ固体氧化物燃料电池的性能通过在800°C至900°C的温度范围内的氢气（燃料电极）和合成空气（氧气电极）气氛下测量极化曲线来评估℃。
Planar and corrugated 8YSZ freestanding membranes were fabricated by means of SLA 3D printing after sintering at high temperatures to obtain crack-free and homogeneous parts. Overall, the 3D printed YSZ parts are considered suitable for working as electrolytes in SOFC/SOEC applications. The performance of the planar and corrugated LSM–YSZ/YSZ/Ni–YSZ solid oxide fuel cells was evaluated by measuring polarization curves under hydrogen (fuel electrode) and synthetic air (oxygen electrode) atmospheres in the temperature range between 800 °C and 900 °C.
具有常规（平面）和增强区域（波纹）架构的电解质支持的固体氧化物电池已通过陶瓷3D打印技术成功制造。具有平面几何形状的3D打印固体氧化物电池在燃料电池和共电解模式下均表现出良好的性能（与常规电池相比）。更有趣的是，波纹状细胞显示出的改善与3D结构实现的活性面积的增加成正比。在这项工作中，与传统的SOFC技术（LSM–YSZ / YSZ / Ni–YSZ）相比，直接提高了60％，在900°C时可获得410 mW cm-2的出色最大功率密度。
Electrolyte-supported solid oxide cells with both conventional (planar) and enhanced-area (corrugated) architectures were successfully fabricated with ceramic 3D printing technologies. 3D printed solid oxide cells with planar geometry presented a good performance (comparable to conventional cells) in both fuel cell and co-electrolysis mode. More interestingly, corrugated cells showed an improvement directly proportional to the increase of their active area achieved by 3D structuration. In this work, a direct increase of 60% on conventional SOFC technology (LSM–YSZ/YSZ/Ni–YSZ) was reached obtaining an excellent maximum power density of 410 mW cm−2 at 900 °C.
类似地，在以共电解模式运行的波纹状固体氧化物电解槽中注入了1.3 V时600 mA cm-2的高电流密度。此外，即使在高电流密度条件下（在850°C下j = 360 mW cm-2），经600小时持续时间的耐久性测试也证明了增强细胞的降解极低。这些优异的结果可以被认为是制造新一代固态氧化物电池的第一步，这种固态氧化物电池的性能与其从平面到三维的自然变化有关。此增强功能超出了其波纹电解质的高纵横比，并且包括具有嵌入式功能和改进的可堆叠性的3D打印结构元素。这项工作的3D打印方法代表了一种通用的方法，可以增加高性能和耐用复杂设备的设计自由度，并且是能源行业增材制造革命的一步。
Similarly, a high current density of 600 mA cm−2 at 1.3 V was injected in a corrugated solid oxide electrolysis cell operating in co-electrolysis mode. Moreover, a remarkably low degradation of the enhanced cells was proved in durability tests of 600 h of duration even at high-current density conditions (j = 360 mW cm−2 at 850 °C). These exceptional results can be considered the first step for the fabrication of a radically new generation of solid oxide cells with enhanced performance related to their change in nature from planar to three-dimensional. This enhancement goes beyond the high-aspect-ratio of their corrugated electrolyte and includes 3D printed structural elements with embedded functionality and improved stackability. The 3D printing methodology of this work represents a versatile approach that increases the design freedom for high performing and durable complex devices and a step forward in the revolution of the additive manufacturing in the energy sector.