Bifunctional Electrocatalysts For Rechargeable Zinc-air Batteries

  • Author / Creator
    Elaheh, Davari
  • With the rapid development of electrified transportation, electrochemical energy storage devices will be more important than they have ever been in human history. Lithium-ion batteries are considered as the most energy efficient candidates, due to their relatively long cycle life. However, their limited energy density, as well as the safety issues, are concerns for their long-term application. As an attractive alternative, metal-air batteries have generated interest as promising large-scale electricity storage technologies. The light-weight architecture of metal-air batteries can provide high energy density with a simple and low cost cell design. Among various types of metal-air batteries, Zn-air batteries (ZABs) and Li-air batteries have been considered as the most promising metal-air batteries. Compared with Li, Zn is a more attractive metal due to its lower cost, abundance and environmentally friendliness. However, there are several technical issues associated with the structure of ZABs, including insufficient cycling durability, low charge-discharge activity and limited power density. One of the critical issues of rechargeable ZABs is the large overpotential associated with the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in the air cathode. Accordingly, developing novel bifunctional catalysts, which can enhance the kinetics of both OER and ORR, is one of the most critical factors to propel the ZABs to practical energy applications. Currently, the most effective bifunctional catalysts are based on precious metals (Pt-Ir based). However, the high cost and scarcity of precious metals limit their widespread use and remains a huge challenge for developing air cathodes. Therefore, it is important to develop inexpensive, stable and abundant non-precious metal catalysts in the design of ZABs. The purpose of this work is to design and synthesize novel non-precious metal catalysts among a wide range of materials using simple techniques. Non-precious metal materials are investigated in this thesis as potential ORR/OER catalysts, including Mn-Co mixed oxides, Mn-nitride, N-doped hollow mesoporous carbon and carbon coated N-doped Fe3O4.

  • Subjects / Keywords
  • Graduation date
    Spring 2017
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.