Controllable Electrochemical Fabrication of KO2-Decorated Binder-Free Cathodes for Rechargeable Lithium-Oxygen Batteries

Wei Yu, Huwei Wang, Lei Qin, Junyang Hu, Liang Liu, Baohua Li, Dengyun Zhai, Feiyu Kang

Research output: Contribution to journalArticlepeer-review

Abstract

Understanding the electrochemical property of superoxides in alkali metal oxygen batteries is critical for the design of a stable oxygen battery with high capacity and long cycle performance. In this work, a KO2-decorated binder-free cathode is fabricated by a simple and efficient electrochemical strategy. KO2 nanoparticles are uniformly coated on the carbon nanotube film (CNT-f) through a controllable discharge process in the K-O2 battery, and the KO2-decorated CNT-f is innovatively introduced into the Li-O2 battery as the O2 diffusion electrode. The Li-O2 battery based on the KO2-decorated CNT-f cathode can deliver enhanced discharge capacity, reduced charge overpotential, and more stable cycle performance compared with the battery in the absence of KO2. In situ formed KO2 particles on the surface of CNT-f cathode assist to form Li2O2 nanosheets in the Li-O2 battery, which contributes to the improvement of discharge capacity and cycle life. Interestingly, the analysis of KO2-decorated CNT-f cathodes, after discharge and cycle tests, reveals that the electrochemically synthesized KO2 seems not a conventional electrocatalyst but a partially dissolvable and decomposable promoter in Li-O2 batteries.

Original languageEnglish
Pages (from-to)17156-17166
Number of pages11
JournalACS Applied Materials and Interfaces
Volume10
Issue number20
DOIs
Publication statusPublished - 2018 May 23
Externally publishedYes

Keywords

  • K-O battery
  • Li-O battery
  • binder-free
  • solution-growth mechanism
  • superoxide

ASJC Scopus subject areas

  • Materials Science(all)

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