Effect of Electrolyte Amount on Electrochemical Properties of Coin-Type Lithium-Ion Cells

Abstract

Most of electrochemical data in published papers are obtained from coin-type cells, which consist of small disc-type cathode/anode pairs, a little larger separator, and excess liquid electrolyte. In particular, comparing to commercial LIB cells, it should be clearly understood that too much electrolyte can give a positive or negative effect on electrochemical properties. However, there have been few reports on this issue, and they are not fully investigated. Thus, we try to figure out this point with coin-type cells. The amounts of liquid electrolyte are controlled by measuring the coin cell mass difference before and after assembly. Three different coin cells are evaluated to compare the initial discharge capacity and coulombic efficiency, electrochemical impedance, c-rate capability, and cycle life at room temperature. And then, the operating or storing temperatures are also changed. Finally, some electrolyte additives are also investigated under the different liquid electrolyte amounts in coin cells. Acknowledgements This work was supported by the Energy Technology Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20142010102980)