Improvements in structural battery cells processing: manufacture, characterization, and multicell demonstration
Examensarbete för masterexamen
Siam Siraj, Mohammad
The road to a sustainable future involves the electrification of the transportation industry and one of the greatest challenges in it is electrical energy storage. Lightweight batteries serving dual purpose of storing electricity in structural load paths show great promise as a steppingstone in overcoming that challenge. While previous research successfully reported such multifunctional structural battery cells, the low energy density and lack of a manufacturing method to produce repeatable cells remain major concerns. This thesis introduces a robust manufacturing method comprising of the well-known vacuum infusion of composite materials to produce structural composite cells with repeatable performance. Manufactured cells are also presented in a six-cell structural battery composite laminate demonstrator where cells that can be connected in any desired configuration, performance of three such configurations have been portrayed experimentally. The composite cell components are carbon fiber cathode, lithium-iron-phosphate coated aluminum anode, and a separator material all infused with structural battery electrolyte (SBE) resin. The manufacturing method has a 100% success rate of producing working cells with 70% of them having repeatable and high performance. Cells with Whatman GF/A and glass fiber plain weave separators features an unmatched 30.0 Wh kg-1 and 41.2 Wh kg-1 energy densities, respectively. The effects of low pressure on SBE as well as the reduction in high state-of-charge surface impedance and charge resistance of individual cells have also been reported. With such performance, these multifunctional materials can reduce the burden from conventional batteries and lighter means of transportation or other goods can be achieved.