Time-dependent global sensitivity analysis with active subspaces for a lithium ion battery model

TL;DR

This paper extends active subspace methods to time-dependent models and applies it to a lithium ion battery simulation, revealing low-dimensional structures that aid in understanding parameter sensitivities.

Contribution

It introduces a novel extension of active subspace techniques for time-dependent processes and demonstrates its effectiveness on a lithium ion battery model.

Findings

Identified low-dimensional structures in the battery model

Provided sensitivity metrics for parameter influence

Enhanced understanding of parameter effects over time

Abstract

Renewable energy researchers use computer simulation to aid the design of lithium ion storage devices. The underlying models contain several physical input parameters that affect model predictions. Effective design and analysis must understand the sensitivity of model predictions to changes in model parameters, but global sensitivity analyses become increasingly challenging as the number of input parameters increases. Active subspaces are part of an emerging set of tools for discovering and exploiting low-dimensional structures in the map from high-dimensional inputs to model outputs. We extend linear and quadratic model-based heuristic for active sub- space discovery to time-dependent processes and apply the resulting technique to a lithium ion battery model. The results reveal low-dimensional structure and sensitivity metrics that a designer may exploit to study the relationship between parameters and predictions.