Tense Solid Oxide Cells - Boosting Clean Energy Conversion through Nanoscale Strain

从以化石燃料为基础的经济向以可再生能源为基础的净零排放经济的成功转型，关键取决于储存可再生能源并按需释放的能力。固体氧化物电池(SOCs)就是这样一种核心技术，它可以将可再生电能可逆地储存在适用于长途运输、航空和大规模储能的燃料中。最重要的是，SOC可以用来从氢等燃料中生产清洁电力(燃料电池模式)，或者在反向操作时，通过利用二氧化碳将电力转换为氢，甚至转化为其他合成燃料前体(电解模式)。随着SOC越来越多地被使用，它们也需要更高效地运行，更具成本效益和可扩展性。由于SOC是基于将良好的电子和离子导电性与催化活性相结合的材料制成的，因此SOC技术的进步在很大程度上是由寻找具有越来越高导电率的耐用材料推动的。通常，这是通过改变材料的晶体结构和化学成分来实现的。基于物理而不是化学变化的替代方法非常有希望，但需要复杂的设备才能实现，而且不是特别可扩展。一个关键的例子是应变，即通过将材料沉积在具有不同晶体结构尺寸的衬底上，从而人为地扩大或收缩单胞而引入的材料晶体结构的“拉伸”。应变可以是调整材料和提高其性能的非常强大的工具：~2%的膨胀应变为离子的扩散创造了额外的自由空间，将离子的导电性提高了2-3倍，相当于20%的摩尔掺杂4，压缩应变使原子聚集在一起，增加了轨道重叠，为电子传输创造了“高速公路”，从而增加了电子导电性，最终降低了防止降解的有效导电温度。尽管有这些优点，应变和材料‘张紧’的应用仅限于上述生产方法，因此也限于薄膜，它们是二维系统(2D)。对于许多应用和设备，三维(3D)结构是司空见惯的。本博士研究了一种新的方法来解锁材料内部的应变，在3D中，通过在纳米级相互接近的情况下，在材料内部形成一团纳米颗粒，创造出3D-“紧张”的材料和能量转换设备。该项目将使用最先进的设施来测量电子和离子传输特性，准备和表征材料，并测试它们从氢气(发电)、蒸汽产生氢气(能量储存)以及二氧化碳和蒸汽共电解生成合成气的发电能力，合成气是一种关键的合成燃料/化学品前体(功率到化学品)，以及与同等最先进的系统的基准。除了从事尖端研究，学生还注册了研究员发展研究生证书(PGCert)，这是一种辅助资格，培养学生的技能、网络和职业前景。

Successful transition from a fossil fuel based economy to a net-zero-emissions one based on renewables critically depends on the ability to store renewable energy and release it on demand. Solid oxide cells (SOCs) are such a core technology that can reversibly store renewable electricity into fuels suitable for long-range transportation, aviation and large-scale energy storage. Most importantly, SOCs can be used to produce clean power from fuels such as hydrogen (fuel cell mode), or, when operated in reverse, to convert power into hydrogen, or even into other synthetic fuel precursors by utilizing carbon dioxide (electrolysis mode).As SOCs become increasingly more used, they also need to operate more efficiently and be more cost-effective and scalable. Since SOCs are built based on materials that combine good electronic and ionic conductivity with catalytic activity, advances in SOC technology have largely been driven by the quest to identify durable materials with increasingly higher conductivities. Typically this has been achieved by changing the crystal structure and chemistry of the materials. Alternative approaches based on physical, rather than chemical alterations are hugely promising, but require complex equipment to realize and are not particularly scalable. A key example is strain, or the 'tensing' of material's crystal structure which is introduced by depositing the material on a substrate with different crystal structure dimensions, thus artificially expanding or contracting the unit cell. Strain can be a remarkably powerful tool to tune materials and boost their performance: ~2% of expansive strain creates additional free space for ions to diffuse, boosting ionic conductivity by 2-3 fold, which is equivalent to 20% mol doping4, compressive strain brings atoms together, increasing orbital overlap and creating 'highways' for electron transport, thus increasing electronic conductivity and finally lowers useful conduction temperatures preventing degradation. In spite of these advantages, the application of strain and materials 'tensing' is limited to the production method described above and thus to thin films, which are two-dimensional systems (2D). For many applications and devices, three-dimensional (3D) structures are routinely required.This PhD investigates a new approach to unlock strain within materials, in 3D, by nucleating 'a cloud' of nanoparticles within them, at nanoscale proximity of each other, creating 3D-'tense' materials and energy conversion devices. The project will use state of the art facilities to measure electronic and ionic transport properties, prepare and characterize materials and test them for power generation from hydrogen (power production), hydrogen production from steam (energy storage), as well as carbon dioxide and steam co-electrolysis to syngas, a key synthetic fuel/chemicals precursor (power-to-chemicals) as well as benchmark against equivalent state-of-the-art systems.In addition to undertaking cutting edge research, students are also registered for the Postgraduate Certificate in Researcher Development (PGCert), which is a supplementary qualification that develops a student's skills, networks and career prospects.