Effect of LiCoO<sub>2</sub> Cathode Density and Thickness on Electrochemical Performance of Lithium-Ion Batteries

Choi, Jaecheol; Son, Bongki; Ryou, Myung-Hyun; Kim, Sang Hern; Ko, Jang Myoun; Lee, Yong Min

doi:2013.4.1.27

J. Electrochem. Sci. Technol > Volume 4(1); 2013 > Article

Article

Journal of Electrochemical Science and Technology 2013;4(1):27-33.
DOI: https://doi.org/10.5229/JECST.2013.4.1.27

Effect of LiCoO₂ Cathode Density and Thickness on Electrochemical Performance of Lithium-Ion Batteries

Jaecheol Choi, Bongki Son, Myung-Hyun Ryou, Sang Hern Kim, Jang Myoun Ko, Yong Min Lee

Department of Applied Chemistry, Hanbat National University;Department of Applied Chemistry, Hanbat National University;Institute of Physical Chemistry, MEET Battery Research Centre, University of Muenster;Department of Applied Chemistry, Hanbat National University;Department of Applied Chemistry, Hanbat National University;Department of Applied Chemistry, Hanbat National University;

Abstract

The consequences of electrode density and thickness for electrochemical performance of lithium-ion cells are investigated using 2032-type coin half cells. While the cathode composition is maintained by 90:5:5 (wt.%) with $LiCoO_2$ active material, Super-P electric conductor and polyvinylidene fluoride polymeric binder, its density and thickness are independently controlled to 20, 35, 50 um and 1.5, 2.0, 2.5, 3.0, 3.5 g $cm^{-3}$, respectively, which are based on commercial lithium-ion battery cathode system. As the cathode thickness is increased in all densities, the rate capability and cycle life of lithium-ion cells become significantly worse. On the other hand, even though the cathode density shows similar behavior, its effect is not as high as the thickness in our experimental range. This trend is also investigated by cross-sectional morphology, porosity and electric conductivity of cathodes with different densities and thicknesses. This work suggests that the electrode density and thickness should be chosen properly and mentioned in detail in any kinds of research works.

Keywords: Electrode density, Electrode thickness, Electrode loading, Electrode porosity, Electrochemical performance, Lithium-ion batteries