Design and Optimization of Lithium-Ion Batteries for Electric-Vehicle Applications.

Abstract

Development of alternate energy storage systems for transportation use has been driven by a combination of environmental preservation, fossil fuel price volatility and energy security concerns. Lithium-ion battery has emerged as a favored choice, however its energy density is still orders of magnitude lower than the fossil fuel. There is significant room for improvement in the battery cell and electric vehicle system designs. The objective of this thesis is to automate the design optimization of the lithium-ion battery pack. To achieve this goal three separate optimization problems were formulated to provide guidelines on the cell parameters at optimal solutions. The single cell design optimization is able to quantify the variations of morphological parameters as a constant active mass ratio; the plug-in hybrid vehicle battery design demonstrates an automated design process that considers realistic performance constraints; the multi-cell design approach minimizes the battery pack mass by utilizing separate cell designs to satisfy different constraints. The usefulness of the current framework can be further enhanced by considering various aging mechansims and to perform a design-control coupled multidisciplinary optimization.