Micromechanical Testing of Pristine and Delithiated Single Carbon Fibres for Structural Battery Composite
Examensarbete för masterexamen
Materials engineering (MPAEM), MSc
Ravindranath, Sreehari Batni
Reduction of mass of the battery system in electric vehicles (EV) is one of the major requirements of the use of EV in place of internal combustion (IC) engines. A novel solution to reduce the mass of the system is by replacing the present battery material with multifunctional material. These are the materials that can simultaneously carry the load and act as an electrode for the battery system. In this study, carbon fibre is used as a candidate multifunctional material. This project aims to examine the tensile strength, modulus, and Weibull distribution of pristine and delithiated single carbon fibre. The tensile properties of 25 mm and 15 mm gauge length fibres were examined using a microtester. The fractured surface was investigated with SEM and EDX. The delithiation doesn’t affect the tensile modulus of the fibre. A considerable amount of difference was detected in the Weibull modulus. The Weibull value ’m’ is high for pristine fibre and a bit less for delithiated fibres. The SEM and EDX results showed that there is a slight change in the surface morphology of fibre and an increase in the content of oxygen in delithiated fibres. This can be due to the remnants of lithium from lithiation and delithiation which were oxidized once they were exposed to the atmosphere.
Structural battery composite , lithiation/delithiation , fractography , Weibull modulus , microtester