Optimization and monitoring of environmentally friendly battery packs

Researcher: Ali RAHDARIAN

The project aims at developing safer, long lasting and environmentally friendly lithium ion batteries for use in stationary storage applications. The targeted batteries are made of LTO/LFP electrode materials coated onto current collectors via a novel aqueous preparation pathway. These chemistries are indeed known to be more stable and safer than others. However, there is no guarantee that the manufactured battery is the safest or the one with the best performance among different possible designs. Moreover, currently there is no way to track the progression of its internal state as the battery is operated. These two issues can be addressed through the combination of electrochemistry, mathematical modelling and control theory, three domains of expertise covered by the two partners. Three lines of research will be pursued: the optimal design of a battery cell, the study and modelling of aging for such a cell, and the state monitoring of a battery pack. The battery design optimization seeks to improve the battery performance through appropriate sizing. The associated challenges include the choice of relevant design criteria and degrees of freedom to be optimized. The optimized battery design will be experimentally validated by building the cell and verifying the resulting performance index. The aging model will exploit long term cycling experiments to determine aging as a function of the operating conditions. Such information will be used in the battery pack state monitoring system that aims at estimating the state-of charge and state-of-health of the constituent battery cells. These packs arise when series/parallel arrangements of cells are considered in order to meet voltage/power requirements.