Effect of Center Pin in Free Fall Test for a Cylindrical Li-ion Cell

원형 리튬 전지의 센터 핀이 낙하 충격에 미치는 영향

  • Kim, Simon (Department of Mechanical Design Engineering, Chungnam National University) ;
  • Lee, Young Shin (Department of Mechanical Design Engineering, Chungnam National University)
  • 김성종 (충남대학교 기계설계공학과) ;
  • 이영신 (충남대학교 기계설계공학과)
  • Received : 2015.02.10
  • Accepted : 2015.05.11
  • Published : 2015.06.01


A cylindrical secondary Li-ion cell is a device in which stored chemical energy is converted to electrical energy via an electrochemical reaction. These cells are widely used for applications that require high capacity and rate power, such as notebooks, power tools, and electric vehicles. The role of a center pin is to retain the channel for gas release, preventing blockage of the hollow of the jelly roll during a charge-discharge cycle, and to prevent an internal short circuit for tearing of separator under mechanical free fall. In this paper, two experiments are conducted with and without the center pin to experimentally verify the importance of the role of the center pin. The first experiment is a 50-cycle charge-discharge cycle test, and the second is a free fall test conducted according to the Underwriters Laboratories (UL) standards. Based on these experiments, we demonstrate that the center pin in a cylindrical cell is a very important component in terms of safety.


Cylindrical Li-ion Cell;Center Pin;Free Fall;Cycled Cell


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