材料学硕士论文精心编辑6篇文档格式.docx

1、下面我们就为大家介绍一些材料学硕士论文，学习本专业的同学可以参考一下！ 材料学硕士论文精心编辑6篇第一篇：地开石孔结构调控与在储能电池中的应用 摘要 隔膜是锂离子电池的四大重要组成之一，其性能影响电池的容量、稳定性和寿命。目前，普遍使用的锂离子电池隔膜是聚烯烃类隔膜，尽管此类隔膜有诸多优点，但其较差的热稳定性和电解液润湿性是导致锂离子电池安全事故频发的重要原因。因此，开发高性能隔膜是提高电池安全性的一种有效手段。本文制备多孔地开石涂覆无纺布作为电池隔膜，采用插层和化学反应相结合的方式调控地开石的孔结构，进而调控涂覆隔膜的孔结构。地开石的多孔形貌是通过膨胀剂插层和引发剂在高温条件下的引发实现的，

2、本文首先尝试两种结构相似的膨胀剂（硫脲、尿素）对地开石插层，XRD及FTIR测试结果表明，两种膨胀剂均能插入地开石层间，扩大地开石的层间距，但硫脲插层需要有机分子多次替代才能实现，而尿素则更容易进入地开石的层间形成插层复合物。之后，重点研究膨胀剂尿素和引发剂氯酸钾的用量对地开石狭缝孔形成的影响。TG-DTA结果表明，尿素与氯酸钾的质量比可以调控地开石的片层膨胀程度。地开石片层膨胀形成的狭缝孔尺寸随着尿素与氯酸钾质量比的增大而逐渐增大。当40wt%氯酸钾与质量比3/4的尿素/地开石插层复合物混合煅烧后，地开石形成的多孔结构的孔尺寸达到0.212m. 本文继续探讨了孔结构可调控的地开石对涂覆隔膜的

3、电化学性能的影响，分别测试涂覆隔膜在两种不同电池系统中的性能。实验以丙烯腈多元水共混物（LA133）为粘结剂，以浸涂方式涂覆无纺布。实验结果表明，多孔地开石含量的增加有利于改善涂覆隔膜的孔结构，特别是孔隙度的提高。多孔地开石能够提高隔膜的润湿性，改善电极与电解液的界面兼容性。采用多孔地开石涂覆的隔膜机械强度高于铅酸蓄电池隔膜AGM.高含量多孔地开石涂覆隔膜在ZnSO4和Li2SO4混合水系电解液中的离子电导率为13.12mS/cm.此外，多孔地开石提高了无纺布的尺寸稳定性。在Zn/LiMn2O4水系锂离子电池中，多孔地开石能够有效地抑制欧姆极化，减少界面阻抗。多孔地开石涂覆隔膜表现出极高的放电

4、比容量和倍率稳定性，循环100圈后容量保持率87%,比AGM的容量保存率高5%. 研究证实，膨胀程度不同的地开石对于优化隔膜的孔结构有着极其重要的作用，良好的孔结构能够提高隔膜的孔隙度，增大电解液的容纳量。此外，多孔地开石的羟基有助于离子的传输，抑制电极极化和减小电池的内部损耗。多孔地开石隔膜对水和有机电解液均具有良好的亲和性，提升在溶剂为碳酸乙烯酯（EC）/碳酸二乙酯（DEC）（体积比1/1）的LiPF6电解液中的离子电导率（3.157mS/cm），且离子迁移数达到0.64.甚至，涂覆隔膜在高温下仍能保持极佳的热稳定性。在Li/LiFePO4有机锂离子电池体系中，结构优化最佳的涂覆隔膜具有极

5、高的放电容量和优异的倍率性能，其循环200圈仍能保持93.4%的容量。 关键词：插层，多孔地开石，膨胀程度，水系锂离子电池，有机锂离子电池 Abstract The separator, which affects the interfacial structure, capacity, stability and cyclelife of the battery, is one of the four components of lithium ion batteries. At present,the common commercial separator is polyolefin se

6、parator because of its many advantages. However, the poor thermal stability and electrolyte wettability of polyolefin separators lead to frequent safety accidents. Therefore, the development of high-performance separator is an effective means to improve the safety of batteries. In this paper, interc

7、alation and chemical reaction were applied to adjust the pore structure of the dickite and further regulated the pore structure of the coated separator. The porous morphology of dickite is formed by expansion agent and initiator on the condition of high temperature. The intercalation complexes were

8、prepared by two kinds of expansion agent （thiourea and urea） with similar structures. The results of XRD and FTIR show that two kinds of expansion agent can intercalate dickite interlayer, and expand the interlayer spaces of dickite. The intercalation of thiourea into the interlayer spaces of dickit

9、e requires multiple displacement intercalations of organic molecules, while urea is more likely to form intercalation complexes. The TG-DTA results show that the mass ratios of urea and potassium chlorate could control the expansive degree of dickite. The size of the slit pore of porous dickite incr

10、eases with the increase of the mass ratios of urea to potassium chlorate. Aftercalcining the mixture of 40 wt% potassium chlorate and urea/dickite intercalation complex with a mass ratio of 3/4, the dickite forms the porous structure with channel gap of 0.212 m. In order to investigate the effects o

11、f dickite with tunable pore structure on the electrochemical performance of the coated separator, the performance of the coated separator in two different battery systems was tested. The samples were prepared by dip coating method with acrylonitrile polymer （LA133） as a binder. The experimental resu

12、lts show that the increased content of the porous dickite is beneficial to improve the pore structure of the coated separator, especially the porosity. Porous dickite can improve the wettability of the separator and the interfacial stability between the electrode and the electrolyte. The separator c

13、oated with porous dickite has higher mechanical strength than the absorbed glass mat （AGM）。 The ionic conductivity of the high content-porous dickite coated separator in the aqueous electrolyte withZnSO4 and Li2SO4 is 13.12 mS/cm. In addition, the porous dickite enhances the dimensional stability of

14、 the nonwoven fabric. In rechargeable hybrid aqueous batteries with Zn/LiMn2O4, the porous dickite can effectively suppress the ohmic polarization and reduce the interfacial resistance. The high content-porous dickitecoated separator exhibits high discharge specific capacity and superior C-rate stab

15、ility. The capacity retention is 87% after 100 cycles, which is 5% higher than that of AGM. The study confirms that dickite with different expansive degree plays a vital role in optimizing the pore structure of the separator. A good pore structure can increase the porosity and electrolyte uptake of

16、the separator. In addition, the hydroxyl group of the porous dickite contributes to the ion migration, suppresses electrode polarization, and reduces internal loss of the battery. The separator shows favorable affinity for both organic and aqueous electrolytes resulting superior ionic conductivity （3.157 mS/cm） and lithium transference number （0.64） using