金属有机骨架的氧化锌纳米材料的制备及其电化学性能研究
（1）采用溶液法和溶剂热法分别制备前驱体MOF-5a与前驱体MOF-5b。通过热解煅烧得到ZnO纳米多孔材料，然后进一步进行XRD、FESEM等基本表征。结构表征结果表明样品的形貌比较整齐均一，且具有很好的分散性。配合物MOF-5a的形貌为正方体形貌，颗粒尺寸约为3微米，MOF-5b是分散均一的纳米球；吸附脱附测试表明ZnO-a和ZnO-b的孔径分布分别为15 nm和0。7 nm左右。ZnO-a的孔径较大，主要归因于小孔之间的相互作用导致了大孔的形成。
（2）进一步把ZnO纳米多孔材料制备成超级电容器和锂离子电池的电极材料，超级电容器研究结果表明，ZnO-a在电流密度为1 A g-1的首次放电比电容量为153。3 F g-1，循环2000圈后，分别衰减到145。5 F g-1，容量保持率为95 %。因此可知，ZnO-a用作超级电容器电极材料具有很好的循环稳定性，没有明显的容量损失，这主要是由于ZnO-a材料的多孔特性。当ZnO纳米多孔材料作为锂离子电池负极材料时，ZnO-a和ZnO-b的最初放电比容量分别为1162。3和1002。1 mA h g-1，循环10圈后，比容量分别衰减为129。9 mA h g-1、18。3 mA h g-1。
毕业论文关键词：MOF-5；ZnO多孔纳米材料；超级电容器；锂离子电池
Abstract Carbon material is common commercial electrode material。 However, the theoretical capacity is lower。 he theoretical capacity of only 372 mA h g-1。 In order to meet the demand of high power and high energy resource, developing a new generation of lithium-ion battery electrode materials and ultracapacitors is urgency。 Transition metal oxide is the best candidate material, however the electrical conductivity is very poor and structural collapse happened caused by volume expansion/contraction during cycle process。 It is hoped to prepare hollow structured electrode material or nanostructured porous material for solving the above mentioned problems。
(1) In a simple solvothermal strategy, precursor MOF-5a and MOF-5b were prepared by solvothermal and direct method method。 By thermal decomposition of the precursor, we prepared ZnO-a and ZnO-b porous material with the original morphology。 Porous ZnO-a with square shape structures was obtained。 the pore size of ZnO-a and ZnO-b structures is centered at 0。7 and 15 nm。ZnO-a aperture larger, mainly due to small holes caused by the interaction between a large hole formed。
(2) As supercapacitor electrode materials, the specific capacitances of porous ZnO-a nanostructures is 153。3 F g-1。 After 1000 cycles, the specific capacitance still retains 145。5 F g-1 ，which capacity retention rate is 95%。 Therefore, the porous ZnO-a nanomaterials exhibit excellent electrochemical performances, which may be attributed to the smaller particle size and compact porous swith suitable pore size。 As lithium-ion battery anode electrode materials, the initial discharge capacity of ZnO-a and ZnO-b nanostructures are 1162。3 and 1002。1 mAh g-1, respectively。 After, 10 cycles, the reversible capacities still retain 129。9 and 18。3 mAh g-1。
Key words: MOF-5; porous ZnO materials; Supercapacitor; Lithium-ion battery
目录
第一章 绪论 1
1。1 引言 1
1。2锂离子电池简介 1