Sulfur composite cathode materials for rechargeable lithium batteries
Sulfur composite cathode materials for rechargeable lithium batteries
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DOI：
10.1002/adfm.200304284
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发表时间：
2003-06-01
影响因子：
19
通讯作者：
Xu, NX
中科院分区：
文献类型：
--
作者：
Wang, JL;Yang, J;Xu, NX
通过加热聚丙烯腈（PAN）和升华硫的混合物制备了导电聚合物/硫复合材料。在加热过程中，PAN被硫脱氢，形成类似于聚乙炔的导电主链。同时，高极性官能团-CN在熔融状态下环化，形成嵌入硫的热稳定杂环化合物。纳米分散复合材料表现出优异的电化学性能。该复合材料在室温下作为基于聚偏二氟乙烯（PVDF）凝胶电解质的非水锂电池中的阴极材料进行测试，在初始循环中表现出高达850 mAh g(-1)的比容量。 50次循环后其比容量仍保持在600 mAh g(-1)以上，约为LiCoO2的5倍，并且在用新的锂片更换阳极后部分恢复。假设完全反应生成产物 Li2S，电化学活性硫的利用率约为 90%。
Conductive polymer/sulfur composite materials were prepared by heating the mixture of polyacrylonitrile (PAN) and sublimed sulfur. During the heating process, PAN was dehydrogenated by sulfur, forming a conductive main chain similar to polyacetylene. At the same time, the high-polarity functional group-CN cyclized at the melt state, forming a thermally stable heterocyclic compound in which sulfur was embedded. The nanodispersed composites showed excellent electrochemical properties. Tested as cathode material in a non-aqueous lithium cell based on poly(vinylidene fluoride) (PVDF) gel electrolyte at room temperature, the composite exhibited a specific capacity up to 850 mA h g(-1) in the initial cycle. Its specific capacity remained above 600 mA h g(-1) after 50 cycles, about five times that of LiCoO2, and recovered partly after replacement of the anode with a fresh lithium sheet. The utilization of the electrochemically active sulfur was about 90% assuming a complete reaction to the product, Li2S.