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Vol.61, No.11, 849 ~ 857, 2023
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| Title |
| Alleviating the Polysulfide Shuttle Effect by Optimization of 3D Flower-Shaped Vanadium Dioxide for Lithium-Sulfur Batteries |
| 정수환 Su Hwan Jeong , 최현준 Hyeon-jun Choi , 이상준 Sang Jun Lee , 이동박 Dong Park Lee , 엄수윤 Suyoon Eum , 문산 San Moon , 윤종혁 Jong Hyuk Yun , 김주형 Joo-hyung Kim |
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| Abstract |
| With the rapid development of portable devices and Energy Storage Systems (ESS), secondary batteries with high energy density and high capacity are in great demand. Among various candidates, Lithium-sulfur (Li-S) batteries have been considered for next-generation energy devices given their high theoretical capacity (1675 mAh g-1) and energy density (2500 Wh kg-1). However, the commercialization of Li- S batteries faces challenges due to sulfur’s low electrical conductivity and the shuttle effect, caused by the dissolution of lithium polysulfide intermediates in the electrolyte during the charge-discharge process. Herein, to resolve these problems, we report the fabrication of a vanadium dioxide (VO2) composite via a simple hydrothermal method and optimize the structure of VO2 for constructing an effective Multi-Walled Carbon Nano Tube (MWCNT) and 3D flower-shaped VO2 (MWCNT@VO2) binary sulfur host by a simple melt diffusion method. In particular, the polar VO2 composite not only physically absorbs the soluble lithium polysulfides but also has strong chemical bonds with a higher affinity for lithium polysulfides, which act as a catalyst, enhancing electrochemical reversibility. Additionally, MWCNT improves sulfur’s poor electrical conductivity and buffers volume expansion during cycling. The designed S-MWCNT@VO2 electrode also exhibits better capacity retention and cycling performance than a bare S-MWCNT electrode as a lithium polysulfide reservoir.
(Received 12 July, 2023; Accepted 7 August, 2023) |
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| Key Words |
| Lithium-Sulfur batteries, VO2, MWCNT, Melt diffusion |
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