Molybdenum Disulfide/Tin Disulfide Ultrathin Nanosheets as Cathodes for Sodium-Carbon Dioxide Batteries

Karthika Pichaimuthu, Anirudha Jena, Ho Chang, Chaochin Su, Shu Fen Hu, Ru Shi Liu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Metal-CO2 rechargeable batteries are of great importance due to their higher energy density and carbon capture capability. In particular, Na-CO2 batteries are potential energy-storage devices that can replace Li-based batteries due to their lower cost and abundance. However, because of the slow electrochemical processes owing to the carbonated discharge products, the cell shows a high overpotential. The charge overpotential of the Na-CO2 battery increases because of the cathode catalyst's inability to break down the insulating discharge product Na2CO3, thereby resulting in poor cycle performance. Herein, we develop an ultrathin nanosheet MoS2/SnS2 cathode composite catalyst for Na-CO2 battery application. Insertion of SnS2 reduces the overpotential and improves the cyclic stability compared to pristine MoS2. As shown by a cycle test with a restricted capacity of 500 mAh/g at 50 mA/g, the battery is stable up to 100 discharge-charge cycles as the prepared catalyst successfully decomposes Na2CO3. Furthermore, the battery with the MoS2/SnS2 cathode catalyst has a discharge capacity of 35 »889 mAh/g. The reasons for improvements in the cycle performance and overpotential of the MoS2/SnS2 composite cathode catalyst are examined by a combination of Raman, X-ray photoelectron spectroscopy, and extended X-ray absorption fine structure analysis, which reveals an underneath phase transformation and changes in the local atomic environment to be responsible. SnS2 incorporation induces S-vacancies in the basal plane and 1T character in 2H MoS2. This combined impact of SnS2 incorporation results in undercoordinated Mo atoms. Such a change in the electronic structure and the phase of the MoS2/SnS2 composite cathode catalyst results in higher catalytic activity and reduces the cell overpotential.

Original languageEnglish
Pages (from-to)5834-5842
Number of pages9
JournalACS Applied Materials and Interfaces
Volume14
Issue number4
DOIs
Publication statusPublished - 2022 Feb 2

Keywords

  • MoS/SnScathode
  • Na-CObatteries
  • catalytic activity
  • overpotential
  • sulfur vacancies

ASJC Scopus subject areas

  • Materials Science(all)

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