Structural basis of Li-ion batteries functionality

by Anatoliy Senyshyn

Monday 15 Feb 2021, 14:30 → 15:30 Europe/Berlin

Zoom Webinar

*Please note the changed Zoom meeting room!*

 

The energy consumption/production profile of our society is slowly adapting to the demands of technological progress, environmental issues, increasing population and climate change. The fact that we do not necessarily generate power where or when we need it makes the energy storage a key challenge of 21th century. Moreover, transition to renewable energy flows further adds to the relevance in this challenge. Among various technologies of energy storage, electrochemical systems in the form of Li-ion batteries are the most rapidly developing ones. The Li-ion technology is dominating the market of energy storage due to its high energy and power densities (both gravimetric and volumetric), low self-discharge, marginal memory effect etc. In the meantime, lithium-ion batteries totally changed the world of portable devices and tools. In addition, the automotive industry undergoes a substantial transformation towards fully electric drivetrains.
Despite the overall success of the Li-ion technology, the further progress is permanently demanding for lower cost, longer life, safer and higher energy/power density batteries resulting in an active development and research in this field. Modern Li-ion batteries are sophisticated devices, possessing numerous degrees of freedom along with complicated geometries of the electrode integration over different length scales. For studies of a closed system the risks of material’s oxidation and degradation, electrolyte evaporation, cell charge changes etc. needs to be eliminated or properly accounted. This calls for new dedicated experimental techniques, capable to reveal “live” information about processes occurring inside the cell on different length scales. In such instance, methods based on neutron scattering and/or synchrotron radiation are well-established experimental techniques for characterization Li-ion batteries in the non-destructive regime.
In the current presentation, a series of diffraction- and tomography-based methods applied for in situ studies of the structural behavior of state-of-the-art Li-ion batteries and selected materials [1] will be presented. Details of structural organization, lithiation and morphology of battery electrodes during real cell operation will be summarized and discussed with respect to the cell organization [2]. The structural evolution on different length scales and with respect to various factors like state-of-charge [3], temperature and aging factors [4, 5] will be discussed.

 

 

1. Senyshyn, A., et al., High-temperature properties of lithium tetraborate Li2B4O7. Journal of Physics D-Applied Physics, 2012. 45(17): p. 175305.
2. Senyshyn, A., et al., Homogeneity of lithium distribution in cylinder-type Li-ion batteries. Sci Rep, 2015. 5: p. 18380.
3. Senyshyn, A., et al., “In-operando” neutron scattering studies on Li-ion batteries. Journal of Power Sources, 2012. 203: p. 126-129.
4. Muhlbauer, M.J., et al., Effect of fatigue/ageing on the lithium distribution in cylinder-type Li-ion batteries. Journal of Power Sources, 2017. 348: p. 145-149.
5. Petz, D., et al., Heterogeneity of graphite lithiation in state-of-the-art cylinder-type Li-ion cells. Batteries & Supercaps, 2020. n/a(n/a).