Journal of Advanced Chemical Engineering

Correlation between electrolyte characteristics and electrochemical performance in lithium-oxygen batteries

2^nd International Conference on Advances in Chemical Engineering and Technology

November 16-17, 2017 | Paris, France

Shingjiang Jessie Lue and Jing-Chun Tang

Chang Gung University, Taiwan

Posters & Accepted Abstracts: J Adv Chem Eng

Abstract:

Lithium (Li)-oxygen batteries exhibit high charge-discharge capacity and are promising for energy storage applications, such as electrical vehicles. The electrolyte in these batteries play an important role on battery life and performance. In this work, two ether-based organic solvents (diglyme and tetraglyme) and four lithium salts (LiTFSI, LiPF6, LiBOB, and LiClO4) were used to prepare electrolytes and tested for battery discharge voltage and capacity. The electrolyte characteristics, including conductivity, viscosity, contact angle, and thermal stability, were correlated to the battery electrochemical performance. The reproducibility of battery assembly and electrochemical performance was confirm using replicate batteries. The battery was tested for cycling charge/discharge condition between 2 and 4.5 V at 0.1 mA current. The charge or discharge period lasted for 10 h, unless the voltage limit was reached. Our results showed that the carbon cloth-based oxygen electrode can successfully discharge and charge for 10-h cycles. The batteries employing tetraglyme solvent exhibited longer lifetime, and the LiTFSI salt helped battery discharge and reached higher capacity. Among eight different electrolyte combinations, LiTFSI(tetraglyme) had the longest cyclic life (15 cycles, 300 h) and each cycle of discharge capacities was 2000 mAh/g-Pt. The coulombic efficiency was almost 100% in these cycles and the energy efficiency ranged from 64 to 77%.