摘要：在近代许多新电池体系中，锂硫电池具有相对较高的能量密度。单质硫正极的理论比容量达到1672mAh·g-1，与金属锂组成电池时电池对的理论能量密度可达2600Wh·kg-1。此外，作为活性物质的硫单质还具备储量丰富，低毒无害的优点，因此，它被认为是最具潜力的二次电池体系之一。在现阶段，锂硫电池的商业化应用依然受到一些尚未克服的难题的困扰，如硫单质及放电产物硫化锂的电子绝缘性，多硫化锂溶入电解液从而引发的“穿梭效应”以及充放电过程中正极的体积膨胀所造成的结构塌陷等问题导致锂硫电池比容量低，循环寿命短，严重制约着它的实际应用。

故而，为了增加硫正极的稳定性，我们采取碳掺杂的方式让硫单质与碳材料复合，将硫离子吸附在具有介孔和微孔的碳管结构中，防止硫离子大量外迁。

Abstract：In many modern new battery systems, lithium-sulfur batteries had a relatively high energy density. The theoretical specific capacity of the elemental sulfur cathode was 1672 mAh·g-1, and the theoretical energy density of the battery pair can reach 2600 Wh·kg-1 when it was composed of metal lithium. In addition, sulfur as an active material also has the advantages of abundant reserves and lower toxicity and harmlessness. Therefore, it was considered as one of the most promising secondary

battery systems. At this stage, the commercial application of lithium-sulfur batteries is still plagued by some unsolved problems, such as the electronic insulation of sulfur element and discharge product lithium sulfide, the “shuttle effect” caused by lithium polysulfide dissolved into the electrolyte and The structural collapse caused by the volume expansion of the positive electrode in the discharge process leads to a low specific capacity and a short cycle life of the lithium-sulfur battery, which seriously restricts its practical application.

Therefore, in order to increased the stability of the sulfur cathode, carbon doping is used to allow the sulfur element to complex with the carbon material, and the sulfur ions are adsorbed in the carbon tube structure having mesopores and micropores to prevent the sulfur ions from migrating outward in large quantities.

Keywords: lithium-sulfur battery; lithium polysulfide; shuttle effect; energy density; carbon doping

目录

第一章 绪论 1

1引言 11

1.2锂硫电池的研究现状 1

1.3锂硫电池系统 1

1.4锂硫电池的工作机制 2

1.5锂硫电池存在的问题 3

1.6锂硫电池的优点与缺点 3

1.6.1锂硫电池的优点 4

1.6.2锂硫电池的缺点 4

1.7碳硫复合正极 4

1.7.1碳球材料 4

1.7.2一维碳管材料 4

1.7.3二维片层碳材料 5

1.7.4三维多孔碳材料 5

1.7.5元素掺杂碳材料/硫复合物正极 5

1.8研究课题的目的及意义 7

1.9课题研究内容和目的 7

参考文献..错误！未定义书签。第二章碳掺杂对材料电化学性能的改性研究 9

2.1引言