Jacob Hill

Date of Graduation

2017

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Mechanical and Aerospace Engineering

Committee Chair

Ross Ryskamp

Committee Co-Chair

Kenneth Means

Committee Member

Scott Wayne

Abstract

Electric vehicles are becoming more popular for manufacturers as emissions restrictions for internal combustion engine (ICE) powered vehicles become tighter. The primary objective of this study was to characterize a battery electric vehicle (BEV) with respect to energy consumption as well as emissions from the battery or propulsion system. It was also desired to compare the BEV to internal combustion engine (ICE) powered vehicles in its class considering greenhouse gases, as well as energy economy, miles per gallon (MPG), and miles per gallon equivalent (MPGge) efficiency.;Tesla is a forerunner in BEVs. The approach they took in making their battery pack is different from any other BEV manufacturer. The Tesla battery pack or energy storage system (ESS) is constructed out of thousands of 18650 style lithium ion battery cells through a partnership with Panasonic. The tooling for these battery cells was already established which keeps costs down. This unique design allows Tesla to have one of the cheapest ESS cost per kilo-watt-hour of any manufacturer.;A 2013 Tesla Model S P85 was exercised on a chassis dynamometer along with on road testing consisting of a CAFEE Morgantown Route and Bruceton Mills Route to characterize its energy consumption. Energy consumption data was measured with a current clamp on the positive high voltage battery cable and voltage probes contacting the high voltage busbar. Vehicle speed was recorded from the chassis dynamometer and a global positioning system (GPS) when operating the vehicle on-road.;Battery electric vehicles do not have a tailpipe and thus do not produce tailpipe emissions like an internal combustion engine powered vehicle does. However; it was desired to investigate if the ESS or propulsion system emitted any gases. A sample manifold was fabricated to mount to the battery pack vent. Samples were taken with and without a sample pump during charging, highway driving, and dynamometer testing. These samples were analyzed with a Fourier transform infrared (FTIR) analyzer and a gas chromatograph (GC) analyzer.;A bench top experiment was devised in an attempt to determine the source of the gases emitted from the vehicle's ESS. Six Tesla 18650 style battery cells were purchased and installed into a test rig. These cells were then charged and discharged to determine if there was any gases emitted from the cells themselves. Exercising the battery cells outside of the ESS did not produce any of the emissions observed while examining the ESS on the vehicle. Through these experiments it was concluded that the gases emitted from the ESS on the vehicle were a result of damaged cells or deterioration of other construction materials. Furthermore, it was also possible that the ESS was acting as a thermal pump due to ambient temperature changes within the ESS.

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