Identification of Life Models for Li-Ion Batteries Using Penalized Regression and Bilevel Optimization

Conference · Fri Mar 26 04:00:00 EDT 2021

OSTI ID:1774844

Gasper, Paul; Smith, Kandler

Reduced-order physics-based life models are extremely useful for rapidly predicting battery state-of-health and for simulating battery lifetime in arbitrary aging conditions. However, identification of well-parameterized models is difficult. This is because, for maximum usefulness in predicting lifetime under a variety of conditions, aging test data exhibits many degradation mechanisms, which all need to be accurately modeled. However, because aging tests are time-consuming and expensive, especially for large-format batteries, a minimum of tests are conducted while probing many stress factors. Building a well-parameterized model is then very challenging: an under-parameterized model will neglect critical degradation modes, and an over-parameterized model will extrapolate poorly to new testing conditions. To complicate this matter, the functional form of the model for any individual degradation rate can be very difficult to identify. In this work, the statistical tools of penalized regression and bilevel optimization are used to help identify both the functional forms of and optimize the parameters of reduced-order life models, accelerating identification of robust models. Model robustness is demonstrated through traditional statistics methods of cross-validation and sensitivity analysis, uncertainty quantification through bootstrap resampling and Monte-Carlo simulation, and simulation of real-world use cases.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1774844
• Report Number(s): NREL/PR-5400-77973; MainId:31882; UUID:1adc57d5-4571-4e00-9557-d348e215afb3; MainAdminID:21151
• Country of Publication: United States
• Language: English

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degradation modeling
lithium-Ion batteries
machine learning
uncertainty quantification