Dynamic analysis of lithium ion transfer at electrode/solid electrolyte interfaces in all solid state lithium ion batteries under charging condition using ERD technique

Title : Dynamic analysis of lithium ion transfer at electrode/solid electrolyte interfaces in all solid state lithium ion batteries under charging condition using ERD technique

Abstract:

An oxide-based solid-state rechargeable lithium ion (Li⁺) battery is one of the most remarkable next generation devices. To realize the product, it is essential that we have information on the Li⁺ ion transfer resistance at electrode/solid electrolyte interfaces and grain boundaries in the solid-state Li⁺ ion batteries.

In the present study, we have in situ investigated the static Li depth distributions around each interface such as 14 nm Au current collector/88 nm LiCoO₂ positive electrode/150 mm Li_1+xAl_xGe_yTi_2-x-yP₃O₁₂–AlPO₄(LATP) solid electrolyte and LATP negative electrode/10 nm Pt current collector in Au/LiCoO₂/LATP/Pt batteries under charging at various voltages up to 2.04 V using high-energy ion beam analysis of elastic recoil detection equipping a time-of-flight high resolution system (ToF-ERD) and Rutherford backscattering spectrometry (RBS) techniques with 9.0- MeV copper ion (Cu¹⁰⁺) probe beams from a tandem accelerator.

The ToF-ERD spectra from the Au current collector in Au/LiCoO₂/LATP/Pt revealed that the Li concentration in the LiCoO₂ gradually decreased with the gradient by increasing the charged voltages and, in addition, the Li depletion region was formed inside the LATP electrolyte near the LiCoO₂/LATP interface with the thickness of approximately 150 ± 10 nm. On the other hand, those from the Pt current collector revealed that the Li concentration in the LATP region of approximately 240 ± 10 nm from the LATP/Pt interface increased with the gradient by increasing the charged voltages. Therefore, it could be concluded that the Li migration from the LiCoO₂ positive electrode to the LATP negative one in the battery was dynamically observed under the various charges using the ToF-ERD technique with the reliable depth resolution in approximately a tens of nanometer scale.

Biography:

Prof. Bun Tsuchiya studied Materials Science at Nagoya University, Japan, and received his PhD degree in March 1998. He then obtained the position of an assistant professor in April 1998 at Institute for Materials Research, Tohoku University, Japan, and the positions of an associate professor in April 2010 and a professor in April 2017 at the Faculty of Science and Technology, Meijo University, Japan. He has published more than 200 research articles in SCI (E) journals.