Molybdenum Disulfide/Tin Disulfide Ultrathin Nanosheets as Cathodes for Sodium-Carbon Dioxide Batteries
Journal
ACS Applied Materials and Interfaces
Journal Volume
14
Journal Issue
4
Pages
5834-5842
Date Issued
2022
Author(s)
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. ?
Subjects
catalytic activity
MoS2/SnS2cathode
Na-CO2batteries
overpotential
sulfur vacancies
Catalyst activity
Cathodes
Electronic structure
IV-VI semiconductors
Layered semiconductors
Lithium compounds
Molybdenum compounds
Nanosheets
Secondary batteries
Semiconducting tin compounds
Sodium Carbonate
Sodium sulfide
Sulfur compounds
X ray absorption
X ray absorption near edge structure spectroscopy
X ray photoelectron spectroscopy
Capture capability
Cathode catalyst
Composite cathode
Cycle performance
Higher energy density
Na-CO2battery
Overpotential
Sulfur vacancies
Ultrathin nanosheets
Carbon dioxide
Type
journal article