Domestic research projects

arrs2.png

Research projects (co)funded by the Slovenian Research Agency.

 

  • Member of University of Ljubljana: UL Faculty of Mechanical Engineering
  • Project code: J7-8270
  • Project title: Next-generation electrochemical LiFePO4 battery model
  • Period: 01.05.2017 - 30.04.2020
  • Range on year: 1,05 FTE
  • Head: prof. dr. Tomaž Katrašnik
  • Research activity: Interdisciplinary research
  • Research Organisation: Link
  • Researchers: Link
  • Citations for bibliographic records: Link
Abstract:

LiFePO cells and other insertion batteries are currently considered as a main battery technology in battery electric vehicles and many other mobile applications. Despite their widespread use, basic phenomena in the cells are still not resolved. This does not only present scientific challenges but, to a much larger extent, also invokes direct societal challenges. Battery safety is namely one of the major implications, whereas incomplete understanding of underlying mechanisms hinders optimization of the components and, even more importantly, their proper use, control and conditioning. Therefore, it is very clear that besides activities in exploring new materials also activities related to understanding and predicting the underlying phenomena are crucial.

The seminal work of two of the researchers of this project provided thermodynamic foundation for understanding particle‐by‐particle (dis)charging in insertion batteries. This opened new perspectives in understanding inhomogeneous (dis)charging of particles in electrodes that inherently decouple global currents and local current densities.

Furthermore, this finding is a key prerequisite for plausible degradation analyses and predictions, as it is not the global cycle rate, but local current per active area, that determines the extent of side reactions, hotspots, shocks and fractures. At present, the community is faced with unusual situation where many details about the processes occurring on nanoscale have been provided, however, the links between these local properties and a general electrochemical output are critically missing. This problem only intensifies when prediction of battery behaviour is needed at non‐standard conditions (high temperatures, prolonged cycling/aging etc.).

To efficiently tackle this challenge, this interdisciplinary project brings together researchers from the material science on one end and energy engineering and modelling on the other. The main goal is to bridge the gap between recent knowledge on the nanoscale and the need for higher fidelity models on the engineering level. The main deliverable of this project will thus be an innovative next‐genera on predictive model for modelling the electrochemical, transport and thermal phenomena including side‐reactions in insertion batteries, which is capable of supporting electrode engineering on the cell level.

To comply with these objectives a multi‐scaling modelling approach will be applied on the cell level. It is estimated that three different scales ranging from the particle over electrode to the cell level are needed to efficiently model all cell relevant phenomena. The project thus, for the first me, bridges the scales “from particle to cell”. Additionally, it innovatively matches and validates models on these scales with original experiments. The proposed project thus features a significant direct scientific impact by pushing the boundaries in modelling of insertion batteries through innovative modelling aspects, innovative experiments and innovative validation driven model development fostering advanced interaction of models and experiments.

Thereby, it will be for the first time possible to predict macroscopic output on the level of cell, while consistently complying with the nanoscopic phenomena. In addition, elaborated model reduction strategies, which will allow tailoring of the modelling depth to the intended application, and model connectivity, further promote scientific and also applied significance of the project. Therefore, the proposed project also features a direct benefit for industry with the end goal being societal benefits.

This project extends the knowledge horizon in the area of LiFePO batteries, however findings can be applied also to other insertion battery materials. The project can thus be considered as a significant contribution to development of next genera on of more powerful, durable, stable and safe batteries.