Heterojunction-composited architecture for Li–O2 batteries with low overpotential and long-term cyclability.

Ge, Bingcheng; Wang, Jing; Sun, Yong; Guo, Jianxin; Fernandez, Carlos; Peng, Qiuming

Abstract

The crucial issue among lithium−oxygen batteries (LOBs) lies in the development of highly efficient catalysts to improve their large discharge−charge polarization, poor rate capability, and short cycle life. Herein, a composite of three-dimensional honeycomb graphene-supported a Mo/Mo2C heterojunction has been synthesized and can be utilized as a self-supported LOB cathode directly. The LOBs based on the Mo/Mo2C heterojunction composite cathode show a low overpotential of 0.52 V, a high discharge capacity of about 12016 mAh g−1 at 100 mA g−1, and a long-term cyclability (about 360 cycles) under a restricted capacity of 1000 mAh g−1 at 100 mA g−1, which exceeds the features of the majority of Mo-based catalysts for LOBs reported so far. Based on both experimental tests and density functional calculations, it is confirmed that the outstanding electrochemical performance is closely associated with a hierarchical porous structure for convenient oxygen/electrolyte diffusion, a large number of activity sites (interfaces/defects) for high capacity, and a high conductivity with metallic bonds for good rate capability. The method can be extended to prepare other metal based heterojunctions.

Citation

GE, B., WANG, J., SUN, Y., GUO, J., FERNANDEZ, C. and PENG, Q. 2020. Heterojunction-composited architecture for Li–O2 batteries with low overpotential and long-term cyclability. ACS applied energy materials [online], 3(4), pages 3789-3797. Available from: https://doi.org/10.1021/acsaem.0c00203

• Journal Article Type: Article
• Acceptance Date: Apr 6, 2020
• Online Publication Date: Apr 6, 2020
• Publication Date: Apr 27, 2020
• Deposit Date: Aug 21, 2020
• Publicly Available Date: Apr 7, 2021
• Journal: ACS Applied Energy Materials
• Print ISSN: 2574-0962
• Electronic ISSN: 2574-0962
• Publisher: ACS Publications
• Peer Reviewed: Peer Reviewed
• Volume: 3
• Issue: 4
• Pages: 3789-3797
• DOI: https://doi.org/10.1021/acsaem.0c00203
• Keywords: Lithium−oxygen batteries; Catalyst; Overpotential; Heterojunctions; Mo-based catalysts
• Public URL: https://rgu-repository.worktribe.com/output/962062