Coupled Multi-Physical Processes in Structural Battery Composites
Examensarbete för masterexamen
Applied mechanics (MPAME), MSc
This thesis examines the change in open cell potential when a structural battery, at a constant state of charge, is exposed to a tensile load. A structural battery full-cell was manufactured. It was electrochemical cycled before being clamped into a tensile machine. In the tensile machine, a potentiostat was connected to the cell which measured the Open Circuit Potential (OCP) while the cell was exposed to a varying tensile load. Two of the three cells used during the experiment were fully delithiated and the third was fully lithiated. The coupling factor was also calculated to gain an understanding of how the cell was affected by different states of charge and different loads. The results show that when the load increases, the cell potential decreases, but when the load decreases, the potential increases. This response is immediate for all three cells and the response of the potential is not strain rate dependent. The state of charge shows that a fully lithiated cell has a lower coupling factor than a fully delithiated cell. This is in accordance with previous experiments in the open literature performed on the half-cell as the cell shows a similar behavior, but the coupling factor is higher for the delithiated cell than for the lithiated cell. The conclusion that can be drawn after performed experiments is that the model used works to validate and investigate the behavior of the coupling factor in the full-cell under different states of charge and varying tensile loads.
Structural Batteries , Composites , Carbon fiber , Piezo-electrochemical effect