An Integrated Na<sub>2</sub>S−Electrocatalyst Nanostructured Cathode for Sodium–Sulfur Batteries at Room Temperature
Room-temperature sodium–sulfur (RT Na–S) batteries offer a superior, high-energy-density solution for rechargeable batteries using earth-abundant materials. However, conventional RT Na–S batteries typically use sulfur as the cathode, which suffers from severe volume expansion and requires pairing wi...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-12-01
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| Series: | Batteries |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2313-0105/11/1/9 |
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| Summary: | Room-temperature sodium–sulfur (RT Na–S) batteries offer a superior, high-energy-density solution for rechargeable batteries using earth-abundant materials. However, conventional RT Na–S batteries typically use sulfur as the cathode, which suffers from severe volume expansion and requires pairing with a sodium metal anode, raising significant safety concerns. Utilizing Na<sub>2</sub>S as the cathode material addresses these issues, yet challenges such as Na<sub>2</sub>S’s low conductivity as well as the shuttle effect of polysulfide still hinder RT Na–S battery development. Herein, we present a simple and cost-effective method to fabricate a Na<sub>2</sub>S–Na<sub>6</sub>CoS<sub>4</sub>/Co@C cathode, wherein Na<sub>2</sub>S nanoparticles are embedded in a conductive carbon matrix and coupled with dual catalysts, Na<sub>6</sub>CoS<sub>4</sub> and Co, generated via the in situ carbothermal reduction of Na<sub>2</sub>SO<sub>4</sub> and CoSO<sub>4</sub>. This approach creates a three-dimensional porous composite cathode structure that facilitates electrolyte infiltration and forms a continuous conductive network for efficient electron transport. The in situ formed Na<sub>6</sub>CoS<sub>4</sub>/Co electrocatalysts, tightly integrated with Na<sub>2</sub>S, exhibit strong catalytic activity and robust physicochemical stabilization, thereby accelerating redox kinetics and mitigating the polysulfide shuttle effect. As a result, the Na<sub>2</sub>S–Na<sub>6</sub>CoS<sub>4</sub>/Co@C cathode achieves superior capacity retention, demonstrating a discharge capacity of 346 mAh g<sup>−1</sup> after 100 cycles. This work highlights an effective strategy for enhancing Na<sub>2</sub>S cathodes with embedded catalysts, leading to enhanced reaction kinetics and superior cycling stability. |
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| ISSN: | 2313-0105 |