Design and optimization of fixture structure with stiffeners for large-scale battery stacks

To reduce the internal resistance of battery cells or electrolyte leakage, stacked type battery packs are typically assembled and are tightly compressed by fixture structures such as endplates. Endplates must have enough rigidity to uniformly compress a battery stack, especially for large-formatted battery stacks. The present study proposes a computational approach to analyze and predict the bending deformation of endplates of stacked type battery packs. Computational result agrees well with the actual measurement of bending deformation in a flow battery stack. Analyzing the stress distribution of endplates, nine stiffener models are considered to minimize the bending deformation by reinforcing the endplates. It is found that the endplate with three vertical stiffeners is the most effective design. Additionally, response surface method (RSM) is conducted to find the optimal value of design parameters for the stiffeners.