Journal of the Korean Electrochemical Society (전기화학회지)

The Korean Electrochemical Society (한국전기화학회)
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Impact of Drying Temperature in High-Loading Positive Electrode Fabrication Process for Lithium-ion Batteries

리튬이온 이차전지용 고로딩 양극 제조공정에서 건조온도의 영향에 대한 연구

  • Min Jin Kim (Graduate School of Convergence Technology and Energy, Tech University of Korea) ;
  • Ji Heon Ryu (Graduate School of Convergence Technology and Energy, Tech University of Korea)
  • 김민진 (한국공학대학교 융합기술에너지대학원) ;
  • 류지헌 (한국공학대학교 융합기술에너지대학원)
  • Received : 2023.12.12
  • Accepted : 2024.01.15
  • Published : 2024.02.29
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Abstract

Among the electrode manufacturing processes for lithium-ion batteries, the drying process is crucial for production speed and process cost. Particularly, as the loading level of the electrode increases to enhance the energy density of the battery, optimizing process conditions for electrode drying becomes more critical. In this study, we compared the drying time and electrochemical performance of the positive electrode prepared at different drying temperatures. LiNi0.6Co0.2Mn0.2O2 (NCM622) was used as the active material and manufactured under various drying temperature conditions ranging from 120 ℃ to 210 ℃ at loading levels of 2.5 and 4.5 mAh cm-2. The physical and electrochemical properties of the electrodes were compared. As the loading level of the electrode increases, the drying time of the electrode also increases, but this time can be reduced by increasing the drying temperature. The drying temperature used in manufacturing the NCM622 positive electrode does not significantly affect the electrochemical performance but drying above 210 ℃ resulted in an increase in the volume resistivity of the electrode and a decrease in electrochemical performance. Accordingly, in the manufacture of high-loading electrodes, the drying temperature was increased to 190 ℃ to shorten the electrode manufacturing time without a loss of performance.

리튬이온 전지의 전극제조 공정 중에서 건조공정은 생산속도 및 공정비용의 측면에서 매우 중요하다. 특히 전지의 에너지 밀도를 높이기 위하여 전극의 로딩레벨이 증가하게 됨에 따라 전극건조의 공정변수의 조정은 더욱 큰 주목을 받게 된다. 이에 본 연구에서는 양극에서의 건조온도를 다르게 하여 전극의 건조시간 및 그 성능에 대하여 비교하였다. LiNi0.6Co0.2Mn0.2O2 (NCM622)를 양극 활물질로 사용하고 2.5 및 4.5 mAh cm-2의 로딩레벨에서, 건조온도는 120 ℃에서 210 ℃까지 다양한 건조온도 조건에서 제조되었다. 이와 같이 제조된 전극들의 물리적 및 전기화학적 특성을 비교하였다. 전극의 로딩레벨이 증가함에 따라 전극의 건조시간은 증가하였으나, 건조온도를 높이게 되면 시간을 줄일 수 있다. NCM622 양극의 제조 과정에서 사용된 건조 온도는 전극의 전기화학적 성능에 큰 영향을 미치지 않았으나, 210 ℃ 이상의 건조에서는 비저항의 증가 및 전기화학적 성능의 저하가 발생하였다. 이에 고로딩 전극의 제조에 있어 건조온도를 190 ℃까지 높여 성능의 손실없이 전극의 제조시간을 단축할 수 있다.

Keywords

Acknowledgement

이 연구는 2023년도 산업통상자원부 및 한국산업기술기획평가원(KEIT) 연구비 지원에 의한 연구임. (20016103, 이차전지 소재부품 시험평가센터 구축사업)

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