Philippe Gyan

Electro-thermal model of lithium-ion batteries for electrified vehicles applications

Lithium batteries are key solutions for sustainable energies storage and particularly interesting for green transportation. Vehicle manufacturers are making a clear transition to a more efficient and ecofriendly transport. In fact, Battery Management Systems (BMS) are crucial for a safe and optimized use of these energy storage systems. This article presents an accurate dynamic electro-thermal model for lithium batteries, designed for high power applications. The model has been implemented using MATLAB (Simulink) and parameters were obtained from experiments. Most parameters depend on current, temperature, and Battery State of Charge (SOC). The accuracy of this model is tested under different operating conditions (static and dynamic current profiles) and simulations are in agreement with experimental results, even after twenty hours of test.

Dynamic Battery Aging Model: Representation of Reversible Capacity Losses Using First Order Model Approach

This article deals about battery capacity ageing model, taking into account battery capacity regeneration during battery rest. In fact the battery capacity losses are modeled as a sum of a reversible part recovered after sufficient rest time and an irreversible part, definitely lost due to battery aging. A 12Ah commercial lithium battery was aged at 45°C with sequences of 5 days under power cycling followed by 2 days of rest, over more than 100 days. The model was implemented using Matlab\Simulink. Simulation results are in agreement with the experimental test, including capacity regeneration and battery capacity losses.

Lithium Battery Aging Model Based on Chemical Rate Approach

This article deals about a lithium battery capacity aging model based on an extended form of Dakins degradation approach. A 12 Ah commercial lithium battery was aged under 3 different temperatures (30, 45, and 60 °C) and state of charge (30, 65, 100%), for a total of 9 different conditions. The logarithm of capacity decay evolves linearly over aging time. The identified slopes from straight lines are sensitive to aging conditions and correspond to battery aging rates. A capacity regeneration phenomenon is also observed in the first aging days. Thus, this phenomenon is analyzed and taken into account in the developed model. The identified expression of aging rates is found similar to Eyrings law. The developed model is confronted to experimental data and simulation shows good results.