Optimization of Aluminium Battery Housing for Electric Vehicles

Abstract

The automotive industry is currently moving from conventional cars to low- and zero-emission vehicles. In this context, the electric vehicle (EV) has become popular with both customers and car manufacturers where an ever-increasing number of models are announced by several car manufacturers which indicates future commitment to the EV. The battery housing is a key component of the modern EV as it contains all the energy for propulsion, protects the batteries from the environment and have a significant effect on the driving characteristics of the vehicle as it often contributes to the strength and rigidity of the chassis. The purpose of this thesis is to improve the design of an existing battery housing for EVs taking manufacturing and assembly considerations into account mainly using aluminium extrusions. The starting point is a design made by Benteler Aluminium Systems Norway AS originally as a tender for a contract competition amongst several suppliers for the battery housing for a car manufacturer. A review of the context into which the battery housing is placed with EVs is executed. An exploration of current manufacturing and assembly processes is conducted in order to establish opportunities and limitations associated with the production of the battery housing. By identifying critical requirements as well as strengths and weaknesses of the original design, areas for improvement on the original design is found. The result is a battery housing design which should have a better battery protection than the original solution. The weight is increased slightly due to a larger floor construction which should aid the protection of the batteries in a collision from X and Y-directions. The added weight is not a desirable attribute but is considered to be a necessary measure to fulfil the requirements. By utilizing the available space underneath the battery modules, an overall reduction of 1 mm in height is achieved. The result is based on utilizing current manufacturing methods and most of the parts are the same as in the original design. Some components in the original design have become redundant and can be omitted in the new design, thus remedying the added weight of the new floor and potentially save costs. The implication of the thesis is limited to dealing with the current battery housing. General ideas and suggestions from the resulted design can however be utilized in similar product applications.