Pre-Study for a Battery Storage for a Kinetic Energy Storage System

This bachelor thesis investigates what kind of battery system that is suitable for an electric driveline equipped with a mechanical fly wheel, focusing on a battery with high specific energy capacity. Basic battery theory such as the principle of an electrochemical cell, limitations and C-rate is explained as well as the different major battery systems that are available. Primary and secondary cells are discussed, including the major secondary chemistries such as lead acid, nickel cadmium (NiCd), nickel metal hydride (NiMH) and lithium ion (Li-ion). The different types of Li-ion chemistries are investigated, explained and compared against each other as well as other battery technologies. The need for more complex protection circuitry for Li-ion batteries is included in the comparison. Request for quotations are made to battery system manufacturers and evaluated. The result of the research is that the Li-ion NMC energy cell is the best alternative, even if the cost per cell is the most expensive compared to other major technologies. Due to the budget, the LiFeMnPO4 chemistry is used in the realisation of the final system, which is scaled down with consideration to the power requirement