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I am a PhD Researcher that focuses on characterising the microstructural behaviour of superalloys.


Pinboard displaying all the novel research areas within metal-supported solid oxide fuel cells

The Search for Alternative Energy Methods

In 10 seconds? Today we see a lot of commercial applications of solid oxide fuel cells (SOFC’s) – London buses for one. The main benefit of SOFC’s is that they produce much less greenhouse gases as opposed to conventional methods. However, much more research is required to fully explore the potential of this energy method.

One interesting development in solid oxide fuel cells was the innovation of metal-supported solid oxide fuel cells. Metal supported solid oxide fuel cells have numerous advantages over conventional ceramic SOFC’S, such as; low material cost, higher thermal shock resistance and much better durability. The drive to reduce the price of fuel cells overall is a global issue and research is ongoing to find ways to reduce the material and also the manufacturing cost.

Don’t believe it? One particular paper has carried out a review of the developments within metal-supported solid oxide fuel cells, with particular interest in the work that has been carried out since 2010 on reducing the cost of these devices - see article “Recent developments in metal-supported solid oxide fuel cells”.

Okay, so how do SOFC’s generate power? In simple terms, a chemical reaction occurs within the SOFC causing the fuel (commonly hydrogen or natural gas) into electricity.

So how does this reaction takes place?

Firstly, we need to understand that an SOFC is made up of three main components; anode, cathode and an electrolyte. To begin the process, hydrogen is passed into the fuel cell at the anode side and at this point its electrons are removed – causing the hydrogen atoms to become ionised and as a consequence of being ionised they are now carrying a positive electrical charge. These ionised hydrogen atoms then pass through the electrolyte (sandwiched between the cathode and anode).

Oxygen enters the fuel cell from the cathode side and combines with the ionised hydrogen atoms that have passed through the electrolyte component of the fuel cell and also combines with the removed hydrogen electrons that have passed through the circuit.


Development of plasma sprayed Ni/YSZ anodes for metal supported solid oxide fuel cells

Abstract: Solid oxide fuel cells (SOFCs) offer a promising technique for producing electricity by clean energy conversion through an electrochemical reaction of fuel and air. Plasma spraying could be a potential manufacturing route for commercial SOFCs, as it provides a distinct advantage especially in case of metal supported cells (MSCs) by allowing rapid processing at relatively low processing temperatures preventing thus the degradation of the metallic substrate. The objective of this work was to develop nickel/yttria stabilised zirconia (Ni/YSZ) anodes with high porosity and homogeneous phase distribution by atmospheric plasma spraying for MSCs. Various feedstock material approaches were explored in this study, both with single injection as well as separate injection of different feedstock materials , and with and without the use of pore formers to create additional porosity. The advantages and issues with each material route were investigated and discussed. It was shown that agglomerated Ni/YSZ/polyester feedstock material resulted in the best distribution of Ni and YSZ in the anode microstructure with homogeneous porosity. Subsequently, the Ni/YSZ/polyester material route with different amounts and size distributions of polyester was chosen to develop anode symmetrical cells using a commercial zirconia sheet as support for electrochemical testing. The Ni/YSZ/polyester anode powder with 10 wt.% standard size polyester exhibited the best electrochemical performance. The results show that plasma spraying of the agglomerated Ni/YSZ/polyester could be a promising route to achieve high performance and rapid production anodes without using the carcinogenic nickel oxide.

Pub.: 09 Sep '16, Pinned: 18 Apr '17

Recent developments in metal-supported solid oxide fuel cells

Abstract: Metal-supported solid oxide fuel cells (MSCs) offer certain strategic advantages over the more conventional solid oxide fuel cells (SOFCs), which comprise only ceramic materials. Since alloys such as ferritic steels are very similar in their coefficient of thermal expansion (CTE) with ceramic components, viz., cerias, zirconias, and nickel oxide doped with either of them, they could provide excellent thermal cyclability while maintaining a strong interlayer bond. Therefore, in an anode-supported cell the entire NiO-ceramic support can be replaced by a ferritic steel porous support—the catalytically active NiO is therefore, a functional layer only. A huge savings in materials cost is achievable, because cerias and zirconias [usually doped with Y, Gd, Sm rare earth (RE) elements] are considerably more expensive that ferritic steels. Lowering the capital costs for SOFCs is an extensive global undertaking with US Department of Energy (DOE) laying down targets such as ~$ 200/kW for the stack itself, in order for SOFCs to become competitive with grid power costs and to offer a power source that promises 24 × 7 power supply for critical applications. This will eventually lead to a premier electricity generation device in the distributed power space, with the highest known electrical efficiencies (>50%). MSCs need very robust, high precision, and cost-effective manufacturing techniques, which are scalable to high volumes. One of the main goals in this review is to showcase some of the work done in this area since the last review (2010), and to assess the technology challenges, and new solutions that have emerged over the past few years.For further resources related to this article, please visit the WIREs website.

Pub.: 30 Mar '17, Pinned: 18 Apr '17