Batteries, Vol. 7, Pages 41: Absolute Local Quantification of Li as Function of State-of-Charge in All-Solid-State Li Batteries via 2D MeV Ion-Beam Analysis
Batteries doi: 10. 3390/batteries7020041
Authors: Sören Möller Takahiro Satoh Yasuyuki Ishii Britta Teßmer Rayan Guerdelli Tomihiro Kamiya Kazuhisa Fujita Kota Suzuki Yoshiaki Kato Hans-Dieter Wiemhöfer Kunioki Mima Martin Finsterbusch
Immediate observation of the lithiation and de-lithiation in lithium batteries on the component and microstructural scale can be still difficult. This work presents recent advances in MeV ion-beam analysis, enabling quantitative contact-free analysis of the spatially-resolved lithium content and state-of-charge (SoC) in all-solid-state lithium batteries via 3 MeV proton-based feature x-ray and gamma-ray emission analysis. The analysis will be demonstrated on cross-sections of ceramic and polymer all-solid-state cells with LLZO plus MEEP/LIBOB solid electrolytes. Various SoC are measured ex-situ and one polymer-based operando cell is charged from 333 K during evaluation. The data unambiguously show the migration of lithium upon charging. Quantitative lithium concentrations are obtained by using the physical and material aspects of the mixed cathodes into account. This quantitative lithium determination as being a function of SoC gives insight into irreversible degradation phenomena of all-solid-state batteries during the first cycles and locations of immobile lithium. The determined SoC matches the electrochemical characterization within uncertainties. The presented evaluation method thus opens up a completely new access to the state-of-charge associated with battery cells not based on electrochemical measurements. Automated ray scanning and data-analysis methods enable a 2D quantitative Li and SoC umschlüsselung on the µm-scale, not accessible with other strategies.
