RELIABILITY STUDY OF BATTERY LIVES: A FUNCTIONAL DEGRADATION ANALYSIS APPROACH

• 成果类型: Article
• 署名作者: Cho, Youngjin; Do, Quyen; Du, Pang; Hong, Yili
• 署名单位: Virginia Polytechnic Institute & State University; Corning Inc; State University of New York (SUNY) System; SUNY Community College
• 刊物名称: ANNALS OF APPLIED STATISTICS
• ISSN/ISSBN: 1932-6157
• DOI: 10.1214/24-AOAS1931
• 发表日期: 2024
• 页码: 3185-3204
• 关键词: remaining useful life; lithium-ion batteries; MODEL; prediction; combination; prognostics; regression; state

摘要

Renewable energy is critical for combating climate change, whose first step is the storage of electricity generated from renewable energy sources. Li-ion batteries are a popular kind of storage units. Their continuous usage through charge-discharge cycles eventually leads to degradation. This can be visualized by plotting voltage discharge curves (VDCs) over discharge cycles. Studies of battery degradation have mostly concentrated on modeling degradation through one scalar measurement summarizing each VDC. Such simplification of curves can lead to inaccurate predictive models. Here we analyze the degradation of rechargeable Li-ion batteries from a NASA data set through modeling and predicting their full VDCs. With techniques from longitudinal and functional data analysis, we propose a new two-step predictive modeling procedure for functional responses residing on heterogeneous domains. We first predict the shapes and domain end points of VDCs using functional regression models. Then we integrate these predictions to perform a degradation analysis. Our functional approach allows the incorporation of usage information, produces predictions in a curve form and thus provides flexibility in the assessment of battery degradation. Through extensive simulation studies and cross-validated data analysis, our approach demonstrates better prediction than the existing approach of modeling degradation directly with aggregated data.