Effect of separator coating layer thickness on thermal and electrochemical properties of lithium-ion secondary batteries

Jung, Min-Gi; Oh, Ji-Hui; Hyun, Da-Eun; Kim, Yong-Nam; Han, Joo-Young; Shin, Weon Ho; Jeong, Kyoung-Hoon; Lee, Dong-Won; Kim, Sunghoon; Oh, Jong-Min; Jung, Min-Gi; Oh, Ji-Hui; Hyun, Da-Eun; Kim, Yong-Nam; Han, Joo-Young; Shin, Weon Ho; Jeong, Kyoung-Hoon; Lee, Dong-Won; Kim, Sunghoon; Oh, Jong-Min

doi:2024.61.6.1112

J. Korean Ceram. Soc. > Volume 61(6); 2024 > Article

Original Article

Journal of the Korean Ceramic Society 2024;61(6): 1112-1122.
doi: https://doi.org/10.1007/s43207-024-00422-9

Effect of separator coating layer thickness on thermal and electrochemical properties of lithium-ion secondary batteries

Min-Gi Jung¹, Ji-Hui Oh^2,3, Da-Eun Hyun², Yong-Nam Kim², Joo-Young Han³, Weon Ho Shin³, Kyoung-Hoon Jeong⁴, Dong-Won Lee², Sunghoon Kim⁵, Jong-Min Oh³

¹Department of Material Science and Chemical Engineering, Hanyang University, Ansan, 15588, Korea
²Material Technology Center, Korea Testing Laboratory, Seoul, 08389, Korea
³Department of Electronic Materials Engineering, Kwangwoon University, Seoul, 01897, Korea
⁴Technical Dept, Daehan Ceramics Co., Ltd, Seoul, 58452, Korea
⁵Center for Brain Busan 21 Plus Program, Department of Applied Chemistry, Dong-Eui University, Busan, 47227, Korea

Correspondence

Dong-Won Lee ,Email: dwlee@ktl.re.kr
Sunghoon Kim ,Email: hoon@deu.ac.kr
Jong-Min Oh ,Email: jmOH@kw.ac.kr

Received: March 19, 2024; Revised: June 3, 2024 Accepted: July 5, 2024. Published online: August 6, 2024.
*Min-Gi Jung and Ji-Hui Oh contributed equally to this work.

ABSTRACT

This study addresses the critical gap in understanding the quantitative relationship between the thickness of ceramic coatings on separators and the overall performance of lithium-ion batteries (LIBs). Through a comprehensive investigation into the effects of varying alumina coating thicknesses on polyethylene (PE) separators, we have elucidated the impact of single-sided and double-sided coatings on separator characteristics and, consequently, on cell performance. Our findings demonstrate that increasing the thickness of the single-sided alumina coating up to 4 µm markedly enhances the mechanical and thermal stability of the separators. Also, we showed the superior thermal stability and electrochemical performance of 2 µm double-sided coating layer compared to 4 µm single-sided coating layer. Utilizing scanning electron microscopy, 3D shape analysis, and a suite of mechanical and electrochemical evaluations, we have detailed the positive ramifications of the alumina coating process. This study not only establishes a clear correlation between alumina coating thickness and separator performance but also advocates for an optimal double-side 2 µm alumina coating. Such a configuration promises to advance the energy density and safety of LIBs, offering insights for future battery development and separator optimization.

Key words: α-alumina · Thickness · Ceramic coated separator · Thermal stability · Lithium-ion battery