Room temperature molten salt as medium for lithium battery

Abstract

Due to the wide electrochemical window and high ionic conductivity, the 1-methyl-3-ethylimidazolium chloride (MeEtlmC1) room temperature molten salt (RTMS) was investigated as the medium for lithium battery in the present work. The addition of C 6H 5SO 2C1 to the RTMS was shown to improve its chemical stability and the reversibility of the lithium electrode because of the removal of A1 2C1 7 - from the melt. Electrochemical reaction which occurred at the LiCoO 2 was studied and the carbon current collector was found to interact with the melt. Out of the various carbon materials studied, graphite was found to be the best material. A LiA1/LiCoO 2 battery using RTMS as the electrolyte was assembled for battery test. Satisfactory results were obtained in preliminary cycling, showing a cell voltage of 3.45 V with better than 90% coulombic efficiency and a discharging capacity of 112 mA h/g LiCoO 2 at current density of 1 mA/cm 2. © 1999 Elsevier Science S.A. All rights reserved.