Self-activated cathode substrates in rechargeable zinc–air batteries

DOI: 10.1016/j.ensm.2020.11.036

Authors: Jian Guo (University College London; Sichuan University) , Liqun Kang (University College London) , Xuekun Lu (University College London) , Siyu Zhao (University College London) , Jianwei Li (University College London) , Paul R. Shearing (University College London) , Ryan Wang (University College London) , Dan J. L. Brett (University College London) , Guanjie He (University College London; University of Lincoln) , Guoliang Chai (Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences (CAS)) , Ivan P. Parkin (University College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Energy Storage Materials , VOL 35 , PAGES 530 - 537

State: Published (Approved)
Published: December 2020
Diamond Proposal Number(s): 22572 , 20847

Abstract: Developing cost-effective and durable air-cathodes is crucial for improving metal-air batteries. Most reports of cathode formulation involve preparing bi-functional electrocatalysts from wet chemistry or solid-state synthesis, followed by pasting onto a substrate. In this work, the cathodes generated from electrochemical activation of normal carbon paper substrates were directly used in Zn-air batteries. The self-activated carbon paper substrate without any additional electrocatalysts exhibits an impressive cycling stability (more than 165 hours for 1,000 cycles) and a small discharge-charge voltage gap. After the activation, the maximum power density and electrochemical surface area were increased by over 40 and 1,920 times respectively. It is discovered that substrates after activation can be directly used as a cathode. The new method is scalable, inexpensive and produces near best in class performance. The mechanism behind this enhancement is due to the creation of oxygen functional groups within the cathode, which overcame slow kinetics, enhanced wettability and enabled optimum three-phase boundaries.

Journal Keywords: Self-activation; Carbon paper substrates; Oxygen functional groups; Air-cathodes; Zinc-air batteries

Diamond Keywords: Batteries

Subject Areas: Materials, Chemistry, Energy

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: E01-JEM ARM 200CF , E02-JEM ARM 300CF

Added On: 07/12/2020 11:49

Discipline Tags:

Energy Storage Energy Physical Chemistry Catalysis Energy Materials Chemistry Materials Science

Technical Tags:

Microscopy Electron Microscopy (EM)