The Study of Surface Modification of Cathode Materials for Lithium-ion Batteries

材料改性是目前锂离子电池材料研究的热点课题，而表面包覆由于能够有效地改善材料的性能，因而受到了人们的广泛关注。本文采用多种结构分析、表面分析、热分析以及电化学研究方法及实验手段，深入研究了TiO2表面包覆对LiNi0.8Co0.2O2正极材料的结构特征、表面性质、电解液分解、热稳定性及电化学性能的影响，并初步考察了LiMn1/3Ni1/3Co1/3O2材料在首次充放电循环中产生较大不可逆容量的原因。本文通过多种表征方法及实验手段证实，表面包覆不会影响LiNi0.8Co0.2O2体相材料中金属离子的氧化态，即Ti元素并没有固溶于LiNi0.8Co0.2O2晶格中，而是主要以氧化物的形式富集在Li...Recently, the modification of material has become a frontier subject in the field of lithium ion batteries. Surface coating is one of the most attractive methods due to its effective improvement of the performance of the electrode materials. In this thesis, the influences of TiO2 surface-coating to structural character, surface properties, electrolytes decomposition, thermal stability and electroc...学位：理学博士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：B20012502

The Study of Lithium Iron Phosphate Production Routes and the Application of DEMS in Lithium Ion Batteries

本报告主要开展两方面的工作，一是开发了磷酸铁锂材料新的合成工艺并对其中试化进行初步探索；二是建立了差分电化学质谱系统并将其应用于锂离子电池体系方面研究。 在磷酸铁锂合成方面，我们开发了新的合成路线，通过两步法合成了LiFePO4/C复合正极材料。通过XRD粉末衍射、元素分析、SEM等手段对合成的材料进行了表征，对合成工艺中的烧结温度、烧结时间、锂源、碳含量等参数进行了优化，确定了实用化合成LiFePO4/C正极复合材料的最优条件。电化学性能的测试结果表明，优化的工艺参数为：碳酸锂为锂源，原料混合物以500rpm球磨4h，高温烧结温度为750oC，烧结时间为1h，产物中碳含量为3.19%。通过...In this report, two parts of work were introduced. First, a new synthesis route of LiFePO4 material was studied and its pilot-technology was also explored. Second, differential electrochemical mass spectrometry (DEMS) technique was developed and applied to the research of lithium ion batteries. In the part of LiFePO4 synthesis, a new two-step route was proposed and a LiFePO4/C composite material...学位：博士后院系专业：物理与机电工程学院物理学系_凝聚态物理学号：BH1700018

含硫添加剂对石墨负极低温性能的研究

锂离子电池的低温性能主要取决于石墨负极,通过添加剂来改善负极的低温性能是研究的焦点之一.本文比较了3种具有不同含硫官能团的添加剂DTD(ethylene sulfate)、1,3-PS(1,3-propane sultone)和ES(ethylene sulfite)对传统商业化材料人造石墨负极低温性能的影响. DFT(密度泛函理论)计算、扫描伏安法(CV)、扫描电子显微镜(SEM)和电化学测试结果表明,3种含硫添加剂均可在人造石墨负极表面参与成膜,并对其低温性能产生比较大的影响.其中,DTD对石墨负极低温性能改善最为明显,1,3-PS对石墨负极的低温性能造成不利影响,而ES则没有明显作用.电化学交流阻抗(EIS)和X射线光电子能谱(XPS)表明,这3种添加剂的不同作用主要在于其所形成的电极界面膜在电化学阻抗方面存在着明显的差异.福建省科技创新领军人才项目;;福建省科技重大专项(No.2014HZ0002-1)资

Progress in Solid-State NMR Studies of Electrode Materials for Lithium Ion Batteries

对于研究材料的结构变化和考察原子所处的化学环境 ,固体核磁共振技术是一种有效的手段。通过6 Li和7Li核磁共振谱的变化 ,可以清楚地了解锂离子电池电极材料中 Li与邻近金属或碳原子的配位情况及在充放电过程中对应于锂离子嵌 /脱过程中材料的结构变化 ,对于研究电极材料的电化学性能有重要的意义。本文综述了固体 NMR技术在研究锂离子电池电极材料的结构及嵌锂机理方面的一些进展Solid-state NMR is the effective technique for the study of local structural changes and chemical environment around the atoms which monitor atomic environments by varying adjacent metal or carbon content. Based on the changes of the 6Li, 7Li NMR spectrum, the coordinating condition of lithium with the neighbor metal atoms and the structural changes of the materials during the charge/discharge cycle can be clearly identified. The developments in the micro-structural analysis of the electrode materials and mechanistic study of Li + intercalation into a various of materials by using solid NMR techniques were reviewed.国家杰出青年科学基金 ( 2 992 5 3 10 )资助课

原发性肝癌组织cyclinB1表达水平及其临床诊断意义

目的探讨细胞周期蛋白B1(cyclinB1)在肝癌组织的表达及其临床诊断意义。方法用逆转录聚合酶链反应(RTPCR)检测40例原发性肝细胞癌患者癌组织及其癌旁组织cyclinB1mRNA的表达。结果90%(36/40)癌组织及85%(34/40)癌旁组织cyclinB1mRNA呈阳性表达,癌组织cyclinB1mRNA表达量为0.531±0.015,明显高于癌旁组织0.263±0.023,两者比较有统计学意义(P<0.05)。cyclinB1mRNA表达与肝癌的病理分级、淋巴转移与否有关,而与性别、年龄、肿瘤大小、癌栓形成与否无关。结论在肝癌发生、发展中,cyclinB1可能起着重要作用,cyclinB1表达水平可作为肝癌分级、分化及癌转移的辅助衡量指标之一

从生态自然观看细菌的耐药

伴随抗菌药物强大的抗感染疗效的同时,细菌等病原体对抗菌药物的耐药性问题日渐显露出来。运用生态自然观辨证地对细菌进行剖析,旨在突破传统思维认识细菌耐药性产生本质,从而更加有效,更加科学地控制细菌耐药的发生

锂离子电池低温性能改善研究进展

锂离子电池因其能量密度高,循环寿命长等优点已成为新型动力电池领域的研究热点,但其温度特性尤其是低温性能较差制约着锂离子电池的进一步使用.本文综述了锂离子电池低温性能的研究进展,系统地分析了锂离子电池低温性能的主要限制因素.从正极、电解液、负极三个方面讨论了近年来研究者们提高电池低温性能的改性方法.并对提高锂离子电池低温性能的发展方向进行了展望.国家重点研发计划(No.2018YFB010400);;福建省高校产学合作项目(No.2018H6020)资

Electrochemical Behavior of Vinyl Ethylene Sulfite as an Electrolyte Film-forming Additive in Lithium Ion Batteries

研究了具有不饱和双键和亚硫酸酯双官能团的乙烯基亚硫酸乙烯酯(VES)作为锂离子电池电解液成膜添加剂对中间相碳微球(CMS)和lIfEPO4电极电化学性能的影响.结果表明:在1MOl/llIClO4/PC电解液体系中,少量的VES(5%)能够在电化学过程中先于PC在CMS表面还原,形成稳定的SEI膜,明显抑制PC和溶剂化锂离子共嵌入石墨层间,改善了电池的循环性能.此外,电解液1MOl/llIClO4/PC+5%VES(V∶V)在lIfEPO4电极中展现出良好的电化学稳定性.A film-forming additive, vinyl ethylene sulfite (VES) with both vinylene group and sulfite group, affects the electrochemical performance of carbonaceous mesophase spherules (CMS) and LiFePO4 electrode.The results indicated that a small amount of VES (5%) could be reduced prior to the propylene carbonate (PC) solvent on the surface of CMS electrode in PC-based electrolyte to form a stable solid electrolyte interphase (SEI) layer, so co-intercalation of PC and solvated lithium ions to graphite could be suppressed.Furthermore, the electrolyte of 1 mol/L LiClO4/PC+5%VES (V∶V) exhibited excellent electrochemical stability in the LiFePO4 electrode.国家自然科学基金(Nos.20473068;29985310);国家“973”计划(No.2007CB209702)资助项

芦荟横切薄层培养再生植株(简报)

以芦荟横切薄层在改良MS+6-BA3.5mg/L(单位下同)+IBA0.3培养基上,芽诱导率可达95%以上;丛生芽于改良MS+6-BA 2.5+IBA0.2培养基培养可增殖;在改良MS+NAA0.5培养基上经15～20d可产生健壮根系

Comparison of gene frequencies of 15 STR loci between patients with primary gastric adencarcinomas and the unrelated locals from Xiamen

目的比较15个短串联重复序列(STR)基因座基因频率在原发性胃腺癌患者和厦门地区正常人群中的分布,推测与胃腺癌相关的基因。方法123份血样采自本地区无癌家族史的健康人群,39份血样采自本地区胃腺癌患者。用聚合酶链反应(PCR)复合扩增结合四色荧光检测方法对血样DNA进行基因型分析,调查本地区健康人群和胃腺癌患者人群的基因频率分布,并根据两者的该15个基因座等位基因频率分布的差异性,推测易感连锁和抗性连锁的等位基因。结果厦门地区胃腺癌患者的TH01、vWA和FAG基因座的等位基因的分布与该地区健康人群比较差异有统计学意义(P<0·01)。在个别等位基因比较中,胃腺癌人群TH01-7的基因频率为0·0385,健康人群TH01-7的基因频率为0·2642,两者差异有统计学意义(P<0·01),相对危险度(RR)=0·1115;胃腺癌人群vWA-15基因频率0·0513,健康人群vWA-15的基因频率0·2927,两者差异有统计学意义(P<0·01),RR=0·1307;胃腺癌人群FAG-18的基因频率为0·1026,健康人群FAG-18的基因频率为0·0163,两者差异有统计学意义(P<0·01),RR=6·8998。结论TH01-7与胃腺癌相关联,其附近可能存在胃腺癌抗性基因;vWA-15附近有可能存在与胃腺癌相关的抗性基因;FAG-18与胃腺癌相关联,其附近可能存在胃腺癌易感基因。Objective To compare the gene frequencies of 15 STR loci between patients with primary gastric adencarcinomas and the unrelated locals from Xiamen in order to search for the genes correlated to the gastric adencarcinomas.Methods The control group consisted of 123 unrelated locals and the testing group was composed of 39 gastric adencarcinomas suffers. All genotypes of the sample DNA were analyzed by gene scan technology and multiplex PCR method with 4-colored fluorescence-labeled primers. All the polymorphic alleles of these 15 STR loci in unrelated healthy locals and patients with primary gastric adencarcinomas had been investigated. The sensitive or resistant genetic factors were inferred according to the statistical difference with distribution of allele frequencies.Results It showed that there were statistic differences (P<0.01)between controls and testing groups in allele frequencies of the three loci: TH01, vWA and FAG. The further exploration of the separated locus revealed that the gene frequency of TH01-7 in the gastric adencarcinomas suffers was 0.0385,but 0.2642 in the control group[P<0.01 and relative risk(RR)=0.1115];the gene frequency of vWA-15 in the gastric adencarcinomas suffers was 0.0513,but 0.2927 in the control group(P<0.01 and RR=0.1307);the gene frequency of FAG-18 in the gastric adencarcinomas suffers was 0.1026,but 0.0163 in the control group(P<0.01 and RR= 6.8998). Conclusions It is very possible that TH01 alleles may be associated with gastric adencarcinomas and it is possible that there is a resistant gene to gastric adencarcinomas near the region of TH01-7 locus; there is a resistant gene of gastric adencarcinomas near the region of vWA-15 locus; FAG alleles may be associated with gastric adencarcinomas and perhaps there is a sensitive gene of gastric adencarcinomas near FAG-18 locus