Gestion de la durée de vie des batteries LiFeMgPO4 pour véhicules électriques au Québec : développement d'un outil d'aide à la décision

Abstract

This study aims to analyze and understand the behavior of LiFeMgPO4 batteries under various charging and temperature conditions, as well as to explore optimal management strategies through the development of a decision support tool to extend their lifespan. Addressing the challenges posed by adverse climatic conditions for electric vehicle (EV) batteries, the study focuses on the specific climate of the Quebec province, considering two extreme temperatures: 30°C and -40°C to best reflect reality. The research is divided into three main axes: a charging system powered by a wind source, a charging system with an ideal current source, and the development of a decision support tool (DST). LiFeMgPO4 technology, belonging to the LFP family, is known for its safety and durability advantages. Its performance at low temperatures is particularly remarkable, demonstrating rapid adaptability and significant robustness compared to other battery technologies. Simulations of the wind-powered charging system, using two different states of charge (SOC) (95% and 35%), as well as simulations of the ideal current source charging system at 30°C, show that the SOC, state of health (SOH), and battery parameters (voltage, current, and internal temperature) are well maintained, with a total number of charging cycles of 2735. At -40°C, the battery adapts to the ambient environment with an initial SOH drop of 28%, proving its adaptability by almost doubling the total number of charge/discharge cycles under normal conditions, reaching 4057 cycles. The DST is designed to optimize battery management by providing information on SOH and proposing options based on assessments concerning reuse, remanufacturing, and recycling. At -40°C, the 28% capacity drop prevented optimal battery use during its first life (between 100% and 80%), thus limiting its use starting from the reuse phase (between 79.99% and 65%) to up to 50% of its capacity, justifying its end of life. This tool also considers the circular economy by attributing a price for each phase of the battery's life to allow the user the option to sell. Additionally, the DST showed an average battery lifespan of 13 years and 6 months at 30°C, compared to 12 years and 6 months at -40°C.

Date	2 Oct 2024
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Julio Cesar Montecinos (Supervisor)