资源描述:
《镁基储氢合金的制备及其电化学性能研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、南京航空航天大学硕士学位论文摘要探索了由机械合金化方法制备非晶态MgNi储氢合金的制备工艺采用机械合金化方法制备了非晶态MgNi+xwt.%B(x=0,2,5,10)和Mg1-xScxNi(x=0,0.01)系列合金运用XRDXPSSEMDSC和电化学性能测试等方法研究了B添加和微量Sc取代Mg对MgNi储氢合金结构与电化学性能的影响规律研究结果表明对MgNi+x%B系合金添加B促进了非晶态合金的形成提高了合金表面Ni与Mg的原子个数比但并没有降低合金表面的氧化程度添加B提高了非晶态合金的热稳定性MgNi+5%B合金的晶化转变温度较MgNi合金提高了11.02合金电极的
2、放电容量随B含量的增加先升高后降低MgNi+5%B合金电极的放电容量较MgNi合金电极提高了21.8%合金电极的循环稳定性随B含量的增加而增加MgNi+10%B合金电极的容量保持率S10较MgNi合金电极提高了67.8%添加B改善了合金电极的动力学性能MgNi+5%B合金电极的高倍率放电能力HRD400交换电流密度I0和极限电流密度IL分别较MgNi合金电极提高了35.0%351.5%和20.2%添加B微弱降低了电极合金氢化物的热稳定性对Mg1-xScxNi系合金微量Sc取代Mg降低了合金表面的氧化程度提高了合金表面Ni与Mg的原子个数比微量Sc取代Mg改善了合金电极的
3、电化学性能Mg0.99Sc0.01Ni合金电极的放电容量容量保持率S10高倍率放电能力HRD200交换电流密度I0和极限电流密度IL分别较MgNi合金电极提高了8.0%14.7%30.4%202.7%和77.8%微量Sc取代Mg显著降低了电极合金氢化物的热稳定性关键词镁基储氢合金机械合金化硼钪电化学性能i镁基储氢合金的制备及其电化学性能研究ABSTRACTPreparationtechniquesforamorphousMgNihydrogenstoragealloywereexploredbymeansofmechanicalalloying.AmorphousMgN
4、i+xwt.%B(x=0,2,5,10)andMg1-xScxNi(x=0,0.01)hydrogenstoragealloysweresuccessfullypreparedbymechanicalalloying,andtheinfluencelawoftheadditionofboronandthesubstitutionofmagnesiumbymicroscandiumonstructureandelectrochemicalpropertiesofMgNihydrogenstoragealloywasstudiedbyXRD,XPS,SEM,DSCandel
5、ectrochemicalpropertiestesting.Theresultscanbeconcludedasfollows:ForMgNi+x%Balloys,additionofboronpromotedthealloytoformamorphousphase,increasedtheatomratioofNi/Mgatthealloysurface,butdidnotdecreasetheoxidationdegreeonthealloysurface.Andtheadditionofboronenhancedthethermalstabilityofthea
6、morphousalloy.AsrelativetoMgNialloywithoutboronaddition,thecrystallizationtemperatureofthealloywith5%Bcontentincreased11.02ºC.Thedischargecapacityofthealloyelectrodesincreasedfirst,andthendecreasedwithincreasingtheadditionofboron.ComparedwithMgNialloyelectrode,thedischargecapacityofMgNi+
7、5%Balloyelectrodewasincreased21.8%.Theelectrochemicalcyclestabilityofthealloyelectrodesincreasedwithincreasingtheadditionofboron.ComparedwithMgNialloyelectrode,thecyclecapacityretentionrateS10ofMgNi+10%Balloyelectrodewasincreased67.8%.Thekineticpropertiesofthealloyelectro