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Sumitomo Rubber Industries, Ltd. is pleased to announce that, as the result of joint research undertaken with Professor Yukio Takahashi of the International Center for Synchrotron Radiation Innovation Smart at Tohoku University and RIKEN and Director Yusuke Tamenori of the Japan Synchrotron Radiation Research Institute, we have established the world’s first^*1 technology that is capable of measuring the structure and chemical state of matter at the nanoscale thanks to the active utilization of the powerful SPring-8^*2 synchrotron radiation facility. Using this new “Tender X-Ray Nanoscope” technology, we have now succeeded in visualizing the sulfur compounds used in lithium-sulfur batteries in greater detail than ever before. We believe that practical applications of this technology will bring about new improvements in battery performance by shedding further light on the mechanisms behind lithium-sulfur battery reactions and eventual degradation, which is an area of ongoing research and development. In addition, by applying this technology to future tire research, we hope to link the results of this research to the development of even higher performance tires in the future.

Sulfur	Lithium-Sulfur Battery Conceptual Diagram

Sumitomo Rubber Industries has long been actively engaged in research involving sulfur, a major raw material in tires that has a significant influence on tire performance as well as performance longevity. Hoping to apply the knowledge that we had accumulated through tire research to other fields, we began joint research and development involving lithium-sulfur batteries with the National Institute of Advanced Industrial Science and Technology in 2011.

Lithium-sulfur batteries not only have an expected theoretical capacity that is six to seven times greater than conventional lithium-ion batteries but are also lighter and safer to use. However, the commercialization of lithium-sulfur batteries has been hindered by their poor cycle life. Improving cycle life will require extremely high-precision measurements of sulfur compounds. And so, our research group set about developing the world’s first “Tender X-Ray Nanoscope” utilizing SPring-8, which enabled us to make use of “coherent Tender X-Rays”. Thanks to this new measuring technology, we have now succeeded in visualizing sulfur compounds at the nanoscale.
 

Image A (Coherent X-Ray Diffracttion Image) is produced by irradiating sulfur compounds with a coherent tender x-ray beam. Phase retrieval calculations are then used to generate Image B (X-Ray Absorption Image) and Image C (X-Ray Phase Image). This process is then repeated at varying x-ray energies. The visualization of the chemical state of the sulfur compounds is achieved through the combination of around 30 of these images.

Moving forward, we are also planning to utilize the 3GeV-class Synchrotron Radiation Facility “NanoTerasu” (which is scheduled to go online in 2024) for measurements of lithium-sulfur batteries under charge-discharge cycling as part of our ongoing efforts to realize practical applications for this technology in the field of materials development. We also look forward to applying this technology in our tire research activities, including deeper analysis of the crosslink structure of the chemical bonds between rubber and sulfur. We are confident that these efforts will contribute to the development of “Performance Sustaining Technology,” which is one of the key technical development themes of our SMART TYRE CONCEPT^*3 for the development of future tires and peripheral services.

In addition, we are also pleased to announce that the results of this research were published in the August 11 (local time) issue of “The Journal of Physical Chemistry C,” which is an academic journal published by the American Chemical Society.

<The Journal of Physical Chemistry C Official Website URL>

https://pubs.acs.org/doi/10.1021/acs.jpcc.2c02795

※1. Based on In-House Research

※2. SPring-8 is the world’s most powerful synchrotron radiation facility. (Location: Sayo, Hyogo, Japan)

※3. SMART TYRE CONCEPT

＜Reference＞

■Tohoku University Press Release

“Measuring Technology Established to Capture the Chemical State of Sulfur at High Resolution (50 Nanometers) – Toward Elucidating the Mechanisms Behind Lithium-Sulfur Battery Reactions & Degradation”