Abstract
This paper focuses on the battery aging of automotive high power lithium-ion batteries intended for 48 V mild hybrid systems. Due to a long vehicle lifetime, battery aging is of high importance, and its consideration within a hybrid system is crucial to ensure a sufficient lifetime for the battery. At the moment, only a few aging investigations and models specifically for automotive high power cells are available. Consequently, all present aging consideration methods are based on the few published aging models focusing on consumer cells. This paper describes the development of an aging model for automotive high power cells and the integration into a mild hybrid operating strategy to actively control the battery aging process during its operation. The underlying aging investigations of high-power battery cells are shown to analyze the main influences of temperature, state of charge, and C-rate. These tests are used to develop the aging model, capable of considering the main influences on the aging process. Based on this model and all gained insights, different methods for considering battery aging in a mild hybrid system are investigated. The goal is to control the aging process during operation and consequently decrease the negative influence. Two active intervention methods are developed and integrated into a 48 V mild hybrid operating strategy to validate their potential. It is possible to control the aging process and at the same time to use the insights for improving the basic hybrid powertrain design regarding reduced aging and battery costs.
Highlights
Future CO2-emission limits and fuel consumption targets for vehicle manufacturers are quite challenging
For validating both active aging consideration methods, they were integrated into the operating strategy of a 48 V-mild hybrid system
A regular 7-gear automatic transmission C-segment car was the simulated load for the turbocharged 1.4 l-SI-engine combined with a mild hybrid system, including a boost recuperation motor of about 10 kW from Bosch
Summary
Future CO2-emission limits and fuel consumption targets for vehicle manufacturers are quite challenging. Mild hybrid systems with an on-board electrical supply voltage of 48 V represent a promising technology approach for a fast and widespread implementation. They achieve substantial fuel consumption savings at lower costs compared to high voltage hybrid electric vehicles or plug-in hybrid vehicles [5, 9, 27]. These mild hybrid powertrains consist of a small electric motor capable of assisting the combustion engine during acceleration (boosting) or recuperating
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
