Mass diffusion controls material structuring from the atomic to the macro-scale defining properties and functionalities.

Gadolinium-doped cerium oxide (GDC) is an attractive ceramic material for solid oxide fuel cells (SOFCs) both as the electrolyte and in composite electrodes operating at low and intermediate temperatures. GDC exhibits high oxygen ion conductivity at a wide range of temperatures and displays a high resistance to carbon deposition when hydrocarbons are used as fuels. However, an inconvenience of ceria-based oxides is the high sintering temperature needed to obtain a fully dense ceramic body. In this study, a green chemistry route for the synthesis of 10 mol% GDC nanoparticles is proposed. The aqueous precipitation method starts from the nitrates of both cerium and gadolinium and uses excess hexamethylenetetramine (HMT) to produce crystalline GDC at 80 ºC. Such a low temperature synthesis provides control over particle size and sinterability of the material at low temperatures.

Electrochemical devices such as solid oxide fuel cells (SOFC) may greatly benefit from the implementation of nanoengineered thin-film multifunctional layers providing, alongside enhanced electrochemical activity, improved mechanical, and long-term stability....

The Solid Oxide Fuel Cell Roll (SOFCRoll) is a novel design based on a double spiral. Combining structural advantages of tubular geometries with processing advantages of thick film methods, it utilises a single cofiring process. The initial concept used separate tape cast layers which were laminated before rolling. To optimise layer thickness to function, thinner screen printed layers were combined into the tape cast structure in 2nd generation cells. This presented several processing challenges, such as achieving dense electrolyte layers, maintaining porous electrode and current collecting layers and incorporation of integral gas channels. Performance has been promising with open circuit voltages close to 1V and cell power of over 400mW at 800°C, however cracking is still evident. Therefore further iterations are in development where thinner layers are sequentially cast, aiming to improve interfacial bonding and better match plasticity and burn out to reduce cracking. This paper reviews key aspects of understanding and development of the SOFRoll , the challenges that have been tackled and what challenges remain, along with future directions for development and potential applications for this device.