简介:TheelectrochemicalformationofMg-LialloyswasinvestigatedinamoltenLiCl-KCl(58-42mol%)eutecticmeltat723K.ThecyclicvoltammogramforaMoelectrodeshowedthattheelectroreductionofLi~+proceedsinasinglestepandthedepositionpotentialofLimetalwas-2.40V(vs.Ag/AgCl).ForMgelectrode,theelectroreductionofLi~+takesplaceatlesscathodicpotentialthanthatattheMoelectrodewhichwascausedbytheformationofMg-Lialloys.PhaseofthedepositedMg-Lialloyscouldbecontrolledbytheelectrolysispotential,andthesampleswerecharacterizedbyX-raydiffractionandscanningelectronmicroscopy.Theresultsshowedthatα-Mgandβ-Liphaseswereobtainedat-2.35and-2.55V,respectively.
简介:Li4Ti5O12(LTO)/carbonnanotubes(CNTs)compositematerialissynthesizedbasedonasolid-statemethodbysand-milling,spray-dryingandcalciningat8508CunderN2flow.TheLTO/CNTssampleswith1wt%and3wt%weightratioofCNTsadditionandthepristineLTOsampleareprepared.TherateperformanceandthethermalstabilityofthesesamplesareinvestigatedbasedonLiMn2O4(LMO)/LTOfull-cell.TheresultsshowthattheweightratioofCNTsadditionhasdistincteffectonLTOperformances.ThecompositematerialsofLTOcompositedCNTshavebetterperformanceathigh-rateduetotheintercalationenhancementbyconductivenetworkofCNTs.Atsecond,theoverchargingtemperatureresponseofthecell’ssurfacewith1wt%CNTsadditionisthelowest.Theparticlesizedistributionismeasuredandthemostuniformparticlesareobtainedwith1wt%CNTsaddition.ThistrendcouldexplainthatthemediumquantityofCNTsisoptimaltoimprovetheheatandmasstransferandpreventtheproblemsofcrystallitegrowinginterferenceandaggregationduringthecalcinationprocess.
简介:本文探讨(CH3Li)4中键的作用,通过计算,发现(CH3Li)4分子的面甲基结构比顶甲基结构要稳定;指出Li—Li间的成键作用相当强,约为Li2分子中键作用的40%左右,估计(CH3Li)4中的J7Li-6Li值约为1Hz。
简介:Li0.33MnO2cathodematerialwassynthesizedbysolidstatereaction.Thematerialshowedasmallcoherentdomainsizeabout10nmdeterminedbyX-raydiffractionandtransmissionelectronmicroscopy.Theelectrochemicalpropertiesofthematerialwerestudiedindifferentpotentialwindowsof3.5―2.0Vand4.3―2.0V.Anirreversibletransformationtospinelphasewasobservedintheinitialseveralcycles,whichwasmoreprominentoncyclingat4.3―2.0V.ElectrochemicalimpedancespectroscopyshowedthattheLi+diffusioncoefficientofthematerialwasabout2×10–9cm2/s.Li0.33MnO2showedareversibledischargecapacityof140and200mA·h/ginthepotentialwindowsof3.5―2.0Vand4.3―2.0V,respectively.Butthecapacityretentionat4.3―2.0Vwaspoorduetothethickerspinellayerformedonthematerialsurface.
简介:研究了电感耦合等离子体原子发射光谱(ICP-AES)法测定Al-Cu-Li系合金中Cu、Li、Ag、Mg和Zr的方法。对样品溶解、共存元素干扰、基体效应进行了研究。采用硝酸和过量盐酸溶解试样,选择Cu324.752nm、Li670.784nm、Ag328.068nm、Mg285.213nm和Zr343.823nm作为分析线。配制标准工作曲线溶液时用纯铝打底消除基体效应。Cu、Li、Ag、Mg和Zr的分析范围分别为0.10%-4.00%、0.10%-2.00%、0.10%-1.00%、0.10%-1.00%和0.01%-0.50%,各元素的检出限均小于0.01μg/mL,加标回收率在94%-106%,相对标准偏差均小于2%,用于标准物质的测定,结果与认定值一致。
简介:Athree-dimensionalfew-layerreducedgrapheneoxide-wrappedmesoporousLi4Ti5O12(m-LTO@FLRGO)electrodeisproducedusingasimplesolutionfabricationprocess.WhentestedasananodeforLiionbatteries,them-LTO@FL-RGOcompositeexhibitsexcellentratecapabilityandsuperiorcyclelife.Thecapacityofm-LTO@FL-RGOreaches165.4mAhg-1after100cyclesbetween1and2.5Vatarateof1C.Evenatarateof30C,ahighdischargecapacityof115.1mAhg-1isstillobtained,whichisthreetimeshigherthanthepristinemesoporousLi4Ti5O12(m-LTO).Thegraphenenanosheetsareincorporatedintothem-LTOmicrosphereshomogenously,whichprovideahighconductivenetworkforelectrontransportation.