Effect of Mixed Conducting Oxide as Catalytic Cathode for Lithium Oxygen Battery

Abstract

The lithium oxygen batteries have received wide attention as an enabling technology for a mass market entry of electric vehicles due to a potential capacity much higher than current Li-ion technology Carbon has been used widely as the basis of porous cathodes for non-aqueous Li?O2 cells produce Li2O2 as the main product that electrically insulative and would passivate the cathode cause very high charge-discharge overpotential which will make kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) more sluggish then compromise the capacity and cycle life Therefore seeking effective electrocatalyst to reduce the overpotential is crucial to enhance the performance of lithium oxygen batteries Mixed conducting oxides have been regarded as the most promising materials due to high electrical conductivity and high electrocatalytic activity for the ORR and OER activity BaxSr1-xCoyFe1-yO3-δ that exhibit defective structures for oxygen vacancy excellent oxygen anion mobility and exchange kinetics make it excellent candidate as cathode electrocatalyst Herein perovskite BaxSr1-xCoyFe1-yO3-δ use as cathode catalyst can increase the discharge capacity from 2705 mAh/g into 5988 mAh/g at 0 1 mA/cm2 and improve cycle stability from 16 cycle to 26 cycle at 0 1 mA/cm2 with limited capacity 1000 mAh/g (Ni Co) Oxide added Carbon-BSCF mixture to improve electronic conductivity increase capacity into 8420 mAh/g Keywords : Lithium Oxygen Battery Catalyst Perovskite

Date of Award	2019
Original language	English
Supervisor	Kuan-Zong Fung (Supervisor)