Enhanced cycle stability of rechargeable Li-O2 batteries using immobilized redox mediator on air cathode

Publication date: 25 March 2020Source: Journal of Industrial and Engineering Chemistry, Volume 83Author(s): Ji-Hoon Baik, Su Young Lee, Kihyun Kim, Seongjun Bae, Sangwan Kim, Soyoul Kwak, Dong Gi Hong, Inho Nam, Jongheop Yi, Jong-Chan LeeAbstractOvercoming the low round-trip energy efficiency and poor cycle stability of lithium-oxygen (Li-O2) batteries still remains a challenge. Here, we show that 2,2,6,6,-tetramethylpiperidinyl-1-oxyl (TEMPO)-immobilized air cathode can effectively reduce the charge voltage and increase the cycle stability in Li-O2 batteries. The TEMPO-immobilized air cathode is prepared using a gas diffusion layer by a simple dip coating method, in which polydopamine is used as a linker. In this method, the immobilized TEMPO on the cathode does not crossover to the anode, and the consumption of TEMPO by side reactions is minimized. As a result, the redox mediation by TEMPO is well maintained in its immobilized state. This highlights that the use of an immobilized redox mediator can be a rational strategy for expanding the practical applications of Li-O2 batteries.Graphical abstract

Source: Journal of Industrial and Engineering Chemistry - January 27, 2020 Category: Chemistry Source Type: research