• Journal of the Korean Electrochemical Society
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• v.24 no.3
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• pp.42-51
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• 2021

Dissociation into Lithium-polysulfide electrolyte due to repeated cycles during the Lithium/Sulfur battery reaction is a major problem of reduced battery lifespan. We searched for a porous carbon with a large specific surface area that infiltrated S to prevent liquid Lithium-polysulfide from being dissolved in electrolyte, induce adsorption of Lithium-polysulfide, and further increase conductivity. In order to obtain porous carbon spheres with a large specific surface area, the carbon spheres of 1939 m²/g were raised to 2200 m²/g through additional KOH treatment. In addition, through heat treatment with S, a carbon sulfur compound containing 75 wt% of S was fabricate and material analysis was conducted on the possibility of using the cathode material. The electrochemical characteristics of the Reference (622; sulfur: 60%, conductive material: 20%, binder: 20%) pouch cell and the pouch cell made using 75wt% of carbon sulfur compound were analyzed. 75wt% of carbon sulfur pouch cell showed a 20% increase in lifespan and 10% improvement in C-rate compared to the Reference pouch cell after 50 cycles.

• 한국전기화학회:학술대회논문집
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• 2003.10a
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• pp.39-39
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• 2003

• Journal of the Korean Electrochemical Society
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• v.27 no.1
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• pp.47-54
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• 2024

In this study, ZIF67/rGO was used to minimize the battery life degradation due to the insulating properties of sulfur and the elution of lithium polysulfide. ZIF67 wrapped in rGO creates more space within the carbon sponge and can hold a large amount of sulfur. The sulfur@ZIF67/rGO composite was synthesized and prepared as a sponge to enhance the sulfur retention capacity. The result showed a high initial capacity, with a value of about 1093 mAh g^-1 and a capacity retention rate of 84% after 100 cycles. The high interaction with sulfur through the complexation of cobalt and carbon confirmed that ZIF67/rGO exhibits high performance as a carrier for sulfur, the anode active material of lithium-sulfur batteries, and the high initial capacity and improved capacity retention rate were confirmed.

• 한국전기화학회:학술대회논문집
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• 2002.04a
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• pp.59-59
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• 2002

• 한국전기화학회:학술대회논문집
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• 2000.10a
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• pp.28-28
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• 2000

• 한국전기화학회:학술대회논문집
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• 1999.04a
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• pp.72-72
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• 1999

• 한국전기화학회:학술대회논문집
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• 1999.04a
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• pp.73-73
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• 1999

• 한국전기화학회:학술대회논문집
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• 2002.10a
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• pp.63-63
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• 2002

• Journal of Hydrogen and New Energy
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• v.17 no.3
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• pp.317-323
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• 2006

Electric conductive material should be homogeneously mixed with sulfur in sulfur electrode fabrication of lithium/sulfur battery, because sulfur is electric insulator. In this paper electrochemical properties of Li/S battery was studied with various compositions of sulfur electrodes. When content of sulfur changed from 40 wt.% to 80 wt.%, the 60 wt.% sulfur electrode showed the maximum capacity of 1489 mAh/g-sulfur. Electrochemical properties of Li/S battery using 60 wt.% sulfur was also investigated with various carbon contents. The discharge capacity changed as a function of carbon contents. The optimum composition was 25 wt.% carbon for 60 wt.% sulfur electrode.

• Journal of Hydrogen and New Energy
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• v.14 no.1
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• pp.46-52
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• 2003

유황 양 전극과 액체 전해질, 리튬 금속을 음극으로 사용한 리튬 유황 전지를 제조하여 그 특성을 조사하였다. 유황 전극은 유황파우더와 carbon black 을 도전재로, 그리고 바인더로 PVdF를 사용하여 제조하였다. 이렇게 제조된 셀은 두개의 다른 전압 구간에서 충방전 실험을 행하였다. 첫 번째 셀은 $S_8+{\chi}Li{\leftrightarrow}Li_2S_x(X=4{\sim}12)$ 반응만을 일어나 게 하기 위하여 2.1V 와 2.5V 사이에서, 그리고 두 번째 셀은 $Li_2S_x+{\chi}Li{\leftrightarrow}Li_2S(x=2{\sim}4)$의 반응만을 일어나게 하기 위하여 1.5V 와 2.5V 에서 충방전 하였다. 그 결과 첫 번째 셀이 더 좋은 싸이클 특성을 가지는 것을 확인 탈 수 있었다. 각 전압구간에서 각 셀이 충방전 되는 동안, 전해질 내로 녹아난 유황의 양은 큰 차치가 없는 것을 확인하였다. 그리고, 전압에 따른 전극의 임피던스를 측정한 결과, 방전이 끝난 후 큰 저항성분이 새로 생긴 것을 확인 할 수 있었다. 이는 사이클이 진행된 후의 전극표면을 SEM 분석을 행한 결과로부터 사이클이 진행된 후 전극 표면에 최종 반응 산물인 $Li_2S$ 가 피막형태로 형성된것을 확인 할 수 있었다.