Design improvements of micro-tubular solid oxide fuel cells for unmanned aircraft applications

Howe, Katie Sarah (2014). Design improvements of micro-tubular solid oxide fuel cells for unmanned aircraft applications. University of Birmingham. Ph.D.

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Abstract

This work contributes to the development of a micro-tubular solid oxide fuel cell (mSOFC) stack for use in a small unmanned aerial vehicle. Fuel cells offer cleaner, near-silent operation. Solid oxide fuel cells were chosen due to their higher efficiency and hydrocarbon fuel tolerance. Micro-tubular cells were chosen due to their simpler sealing requirements and stronger cycling properties. 250 W power is required, necessitating the use of many cells.
Cathode manufacture was considered and various changes to current techniques suggested. Dip-coating was tested as an alternative to brush-painting. The acetone-based ink was unsuitable for dip-coating so a novel, cheaper, water-based ink was developed and a patent application registered.
Cell power, transient and cycling performances were investigated. This transient work is a significant addition to the literature, improving understanding of mSOFC dynamic behaviour. Brush-painted cells take under half a second to adjust to current changes, without voltage overshooting. Dip-coated cells showed weaker performance, potentially due to lower porosity inhibiting mass transport.
A six-cell module was built, using modelling to optimise manifold design, and its power and transient performance assessed. Interconnections present significant issues for mSOFCs. Despite power density decreasing with increasing diameter, fewer, larger tubes were used to reduce this problem. A new interconnection approach was developed, combining current techniques.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):