Improve Rate Capability of the Sulfur Cathode Using a Gelatin Binder
Improve Rate Capability of the Sulfur Cathode Using a Gelatin Binder
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DOI：
10.1149/1.3583375
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发表时间：
2011-06
影响因子：
3.9
通讯作者：
Qinqin Wang;Wei-kun Wang;Yaqin Huang;Feng Wang;Hao Zhang;Zhongbao Yu;An-bang Wang;Keguo Yuan
中科院分区：
文献类型：
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作者：
Qinqin Wang;Wei-kun Wang;Yaqin Huang;Feng Wang;Hao Zhang;Zhongbao Yu;An-bang Wang;Keguo Yuan
通过X射线衍射和扫描电子显微镜研究了放电倍率对明胶粘合剂正极（SGA正极）Li/S电池放电行为的影响，并与聚环氧乙烷（PEO）粘合剂体系（SPA正极）作为对比。研究发现，随着放电倍率的增加，SGA正极表现出较小的平台电位下降趋势和较小的放电曲线形状变化。详细的表征表明，这是由于明胶的分散能力和良好的粘附力，使得元素硫在上部平台区域完全转化为多硫化物，并在放电过程中使阴极结构稳定。在SGA正极（PSGA正极）中开发孔隙可以进一步提高电池的倍率性能，因为多孔结构提供了与电解质更大的接触表面和更短的Li + 离子扩散长度。 PSGA正极在100 mAg ―1 -S时显示出1230 mAhg ―1 -S的初始容量，并在1600 mAg ―1 -S的高放电倍率下保持733 mAhg ―1 -S。
The influence of discharge rate on the discharge behaviour of the Li/S battery with the cathode using a gelatin binder (SGA cathode) is investigated by X-ray diffraction and scanning electron microscopy, with the system using poly(ethylene oxide) (PEO) binder (SPA cathode) as comparison. It is found that SGA cathode shows smaller plateau potential drop trend and less discharge curve shape change with the discharge rate increasing. Detailed characterization reveals that this is due to the dispersion ability and good adhesion of gelatin, which enable complete conversion of elemental sulfur to polysulfide in the upper plateau region and stable structure of the cathode during discharge. Developing pores in the SGA cathode (the PSGA cathode) can further improve the rate capability of the battery, since porous structure provides a larger contact surface with the electrolyte, and shorter Li + ion diffusion length. The PSGA cathode shows an initial capacity of 1230 mAhg ―1 -S at 100 mAg ―1 -S, and remains 733 mAhg ―1 -S at a high discharge rate of 1600 mAg ―1 -S.