PRESS RELEASE〒100-8246 東京都千代田区丸の内１丁目６-2

November 10, 2022

Zeon Collaborates with Waseda University in Establishing Technology for Visualizing Separators to Test the Safetyof Lithium-Ion Rechargeable Batteries
Expected to Further Improve Safety of Lithium-Ion Rechargeable Batteries

Zeon Corporation

Zeon Corporation (head office: Chiyoda-ku, Tokyo, President and CEO: Kimiaki Tanaka) has contributed to establishing atechnology for visualizing separators in collaboration with the Research Organization for Nano & Life Innovation of Waseda
University in its nail penetration test*1 (short-circuit safety test) for lithium-ion batteries (LIBs).
Separators are major components inside LIBs placed between the cathode and anode to ensure lithium ion conductivity while
preventing short circuits between the electrodes. Recent attention to technologies for LIB safety has been particularly focusedon expectations for an improvement of the thermal properties and strength of the separators as well as verifying themechanism behind their performance. In the latest development, operando observation*2 of the nail penetration test wasachieved using a separator visualization technology jointly developed with Waseda University’s Research Organization forNano & Life Innovation. The technology will clarify the role and function of separators and thereby lead to improving the LIBsafety.
Details of the technology will be presented at the 63rd Battery Symposium, to be held at the Fukuoka International ConferenceCenter on November 10.
At the Battery Symposium, Zeon and Waseda University’s Research Organization for Nano & Life Innovation will deliver a jointpresentation titled, “ Operando Analysis of LIB with Visualized Separator Inside during Internal Short-Circuit Test using HighSpeed and High-Precision X-ray Inspection System” The technology involves coating the surface of a separator with metal oxide
particles and using large X-ray scattering cross sections to visualize the behavior of the separator during short circuit safety testing
through direct observation with an X-ray scanner. This is expected to clarify the role and function of separators in battery safety
and accelerate the development of separator materials, which until now has depended on analyzing the electrode short circuit
phenomenon inside LIB cells and the initial process of thermal runaway during short circuit safety tests.
Zeon has been refining its technology for coating materials onto the surface of separators and has established a proven trackrecord based on having developed adhesives for battery separators (product name: AFL®). In this latest achievement, thetechnology was applied to coat oxide particles under optimal conditions, facilitating visualization while maintaining separator
functionality. The application’s success has allowed Zeon to further contribute to improving LIB safety and gain more advanced
material coating technology.
Zeon intends to strengthen its battery materials through its strategy of “polishing up” existing businesses, as stated in its MediumTerm Business Plan. It will therefore continue to develop its business and technologies to further strengthen these materials andcontribute to improving LIB safety while also contributing to the technological development of LIBs in collaboration with theResearch Organization for Nano & Life Innovation of Waseda University and other companies.
*1 A typical LIB safety test, in which a nail is inserted into the LIB to evaluate its resistance to internal short circuits.
*2 Direct observation of phenomena occurring during testing.

For more information, contact:
Department of Corporate Communication, Corporate Sustainability Division, Zeon Corporation
Phone: +81-3-3216-2747