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非晶态电解质的电导率通常是由试验所测得,方法很多,但要受试验条件限制,因此所得结果和实际数值要有些差别,从理论上进行计算得到的结果要更接近其真实值.本文引用能斯特-爱因斯坦(Nernst-Einstein)方程,计算了非晶态电解质Li6Si2O2S5(Li2S-SiS2-Li4SiO4)的理论电导率为10-3S/cm. 相似文献
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用类似于Bellcore方法制备了新型的Li2CO3基多组分塑化薄膜电解质。由聚偏氟乙烯(PVDF)和聚六氟丙烯(HFP)为基体,碳酸锂,纳米二氧化硅和增塑剂邻苯二甲酸二丁酯(DBP)组成。通过交流阻抗测量塑化薄膜电解质的电化学性能,当Li2CO3:SiO2:DBP:2801(PVDF-12%HFP)质量之比等于30:5:30:35时,塑化薄膜电解质具有最高的离子电导率(30℃时是4.3×10-7S/cm,90℃时是4.7×10-6S/cm),且它的活化能仅为0.24eV,相对于碳酸锂晶体的离子电导率具有很强的可比性。加入的增塑剂(邻苯二甲酸二丁酯)和纳米二氧化硅可以降低碳酸锂颗粒之间的阻抗。另外,对于锂离子电池石墨/Li2CO3电解质/石墨而言,电荷转换电阻(即电解质与石墨电极之间的界面阻抗)要明显地比电解质阻抗高一个数量级,且它的活化能仅为0.42eV。这种多组分塑化薄膜电解质为提高充电电池的电解质的热稳定性和化学稳定性提供了一条出路。 相似文献
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《浙江大学学报(A卷英文版)》2016,(2)
目的:合成新型的有机硅基离子塑晶材料[DTMA][TFSI],测试材料的物理和电化学性能,研究其掺杂改性并作为固态电解质用于锂离子电池。创新点:1.合成新型的有机硅基离子型塑晶材料;2.将三元复合塑晶材料作为固态电解质在室温下用于锂离子电池。方法:1.通过热性能分析,得到材料的塑晶温度区间和融化熵值(图1和表1);2.通过电导率测试,确定塑晶掺杂对导电性能的影响(图2);3.通过对扣式电池的充放电性能、倍率性能、循环性能以及阻抗的测试(图4~7),得到塑晶复合物作为固态电解质的电化学性能以及电池循环的稳定性和可逆性。结论:1.合成新型有机硅基离子塑晶材料[DTMA][TFSI],塑晶温度区间为–26°C到54°C;2.在纯塑晶IPC中添加10% LiODFB和10%PC,得到复合物的电导率为1×10~(-4) S/cm,提高塑晶作为固态电解质在室温下应用的可行性;3.将复合物用于LiFePO_4/Li半电池测试,在C/20倍率下,电池的放电比容量为144 mA·h/g,库伦效率为99%。在50次循环后,容量保持率为94%;4.测试结果表明,新型有机硅基离子塑晶的复合物可作为固态电解质材料应用于锂离子电池,以及更高能量密度的锂-硫和锂-空电池。 相似文献
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采用甘氨酸-硝酸盐法(GNP)合成了Pr、Sm、Gd共掺杂的CeO2基PrxGdxSm0.2-2xCe0.8O2-δ(PGSC0、PGSC2、PGSC4、PGSC6、PGSC8、PGSC10,x=0、0.02、0.04、0.06、0.08、0.10)电解质材料,并对其电化学性能进行了表征。XRD测试结果表明,PGSC电解质在600℃煅烧10 h后均形成立方萤石结构。拉曼光谱测试结果表明,Sm、Pr、Gd共掺杂可以有效提高氧空位浓度。PGSC10电解质在800℃时电导率约为0.1 S·cm-1,与Sm0.2Ce0.8O1.9(SDC)(0.115 S·cm-1)电解质大致相同,而在700℃以下,PGSC10电解质的电导率约为SDC的1.5倍,其活化能为0.377 eV,也明显低于SDC(0.626 eV)。因此,PGSC10是一... 相似文献
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通过甘氨酸-硝酸盐(GNP)法合成了Ce0.8Sm0.2O1.9-δ-La0.9Sr0.1Ga0.8Mg0.2O3-δ(SDC-LSGM)复合电解质.采取共燃烧法制备了一系列不同质量百分比的复合粉体以提高这2种粉体的混和均匀度.通过XRD和SEM分析了复合电解质的物相和结构,并且采用直流四端子法和交流阻抗谱研究分析了复合电解质的氧离子电导率.SDC与LSGM的最佳混合质量比为8∶2,其电导率在800℃时为0.113S/cm,而电导活化能仅为0.620eV.交流阻抗谱显示,随着温度的降低,晶界电阻是复合电解质氧离子传输的主要障碍,在SDC中掺入一定量的LSGM不仅可以减少电解质的电子传导,还能改善电解质中晶粒与晶界微观结构,有助于氧离子传导性能的提高. 相似文献
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题型示例一 :弱电解质的电离平衡【例 1】 2 0℃时饱和H2 S溶液 1L ,其浓度为 0 .1mol·L- 1,其电离方程式为H2 SH++HS- ,HS-H++S2 - ,若要使该溶液的pH增大同时使c(S2 - )减小 ,可采用的措施是A .加入适量的水B .加入适量的NaOH固体C .通入适量的SO2D .加入适量的CuSO4 固体解析 :A、B、D三选项都能促进H2 S、HS- 的电离 ,对于A选项加入水后由于溶液体积增大的倍数大于离子数增大的倍数 ,故各种微粒的浓度都要减小 ,符合题意 ;而B选项加入NaOH ,电离平衡向右移动 ,使c(S2 - )增大 ,D选项加入CuSO4 生成CuS沉淀 ,也使… 相似文献
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题目 已知 :一元二次方程x2 -x-1 =0的两根是α、β ,设S1=α+β,S2 =α2 +β2 ,S3=α3+β3,… ,Sn =αn+βn(n为正整数 ) .( 1 )计算 :S1,S2 ,S3,S4 ,S5,S6 的值 .( 2 )从 ( 1 )中的计算中发现什么规律 ?( 3 )利用得出的规律计算 1 +527+1 -527的值 .解 ( 1 )∵ α +β =1 ,αβ =-1 ,∵S1=α +β=1 ,S2 =α2 +β2 =(α+β) 2 -2αβ =3 ,S3=α3+β3=(α2 +β2 ) (α +β) -α2 β-αβ2=(α2 +β2 ) +(α+β) =S2 +S1=4,S4 =α4 +β4 =(α3+β3) (α+β) -α3β -αβ3=(α3+β3) +(α2 +β2 ) =S3+S2 =7,S5=α5+β5=(α4 +β4… 相似文献
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应用电导率仪在293K时测定了稀土盐Er(NO3)3在混合溶剂(DMF-H2O)中的电导率,利用公式计算了Er(NO3)3的摩尔电导率,应用Kohlrausch经验规则,使用Origin软件进行线性拟合,作图外推求得293K时Er(NO3)3在混合溶剂(DMF-H2O)中的无限稀释摩尔电导率λ0=446.48(S.cm2.mol-1),并讨论了293K时浓度对Er(NO3)3在混合溶剂(DMF-H2O)中电导率和摩尔电导率的影响. 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献