碳负载金属氧化物纳米颗粒复合材料的可控合成及其储锂性能研究
发布时间：2018-08-10 16:37
【摘要】：锂离子电池作为能源储存与转化设备广泛的应用在移动设备上。电极材料在调节锂电池储锂性能中的起着重要作用,石墨作为传统的锂电池负极材料比容量较低(～372mAhg-1),不能满足大容量电池的需要,因此需要开发具有高比容量的负极材料。金属氧化物作为锂电池负极材料的一种比容量较高,而且其合成方法简单,自然资源丰富,廉价。但是依旧存在不少问题,在充放电过程中不可逆容量较大,锂离子的反复嵌入脱出易导致电极材料结构发生破坏以及粉化,使得电池的容量严重衰减。为了解决上述出现的问题,我们将金属氧化物与导电性物质相结合,同时调控电极材料的微结构和多孔特性可在一定程度上改善电极材料的储锂性能和结构稳定性。在本论文中我们采用温和的方法制备了金属氧化物纳米颗粒/碳复合材料,并对所合成材料的锂电性能进行了研究。本文中提出了一些新的合成思路,具体内容如下:一、以二氧化硅凝胶为模板合成了 SnO2/多孔碳复合材料(SnO2@PC)。二氧化硅凝胶将葡萄糖和SnO2纳米颗粒固定起来,在一定程度上保证了 SnO2纳米颗粒的分散性,经煅烧后转化为SiO2可充当SnO2@PC的模板。所合成的SnO2@PC复合材料为大块的多孔结构,其比表面积和孔体积分别高达236.22 m2 g-1和0.505 cm3 g-1。SnO2@PC用作锂电池负极材料其首次放电比容量高达1803 mAh g-1,在0.5 A g-1电流密度下,经过300次充放电循环后其比容量高达770 mAh g-1。二、以壳聚糖和四氯化锡为原料,通过壳聚糖的交联和四氯化锡的水解合成了Sn(OH)4@壳聚糖水凝胶,经进一步干燥,煅烧即可得到SnO2@C复合材料。对所合成材料的结构和锂电性能进行了表征和分析,SnO2@C负极材料展示出极好的循环稳定性。SnO2@C复合材料在0.1A g-1电流密度下经100次充放电循环后其容量可达到579.5 mAh g-1,容量保持率大于90%。三、以二氧化硅凝胶为模板,采用SnO2@PC类似的合成思路合成了 TiO2/多孔碳复合材料(TiO2@PC),并对所合成材料进行了结构,形貌表征和储锂性能测试。TiO2@PC同样具有较大的比表面积和合适的孔径分布。TiO2@PC作为锂离子电池的负极材料,当TiO2/葡萄糖的质量比为5/1时所合成电极材料具有最佳的电化学性能,即在0.5 A g-1电流密度测试条件下,经过450次充放电后,其容量还能保持在180 mAh g-1。
[Abstract]:Lithium ion batteries are widely used in mobile devices as energy storage and conversion devices. Electrode materials play an important role in regulating the lithium storage performance of lithium batteries. Graphite, as a traditional cathode material for lithium batteries, has a low specific capacity (372mAhg-1), which can not meet the needs of large capacity batteries. Therefore, it is necessary to develop anode materials with high specific capacity. Metal oxide is a kind of lithium battery anode material with high specific capacity, simple synthesis method, abundant natural resources and low cost. However, there are still many problems. During charge and discharge, the irreversible capacity is large, and the repeated intercalation of lithium ion easily leads to the destruction and pulverization of the electrode material, which makes the capacity of the battery seriously attenuate. In order to solve the above problems, we combine metal oxides with conductive materials, and regulate the microstructure and porous properties of electrode materials to improve the lithium storage performance and structural stability of electrode materials to some extent. In this thesis, the metal oxide nanoparticles / carbon composites were prepared by mild method, and the lithium electrical properties of the composites were studied. In this paper, some new synthetic ideas are proposed. The main contents are as follows: firstly, SnO2/ porous carbon composites (SnO2@PC) were synthesized using silica gel as template. Silica gel immobilized glucose and SnO2 nanoparticles to a certain extent, which ensured the dispersion of SnO2 nanoparticles. After calcination, SiO2 could be used as a template for SnO2@PC. The synthesized SnO2@PC composite is a bulk porous structure with a specific surface area of 236.22 m2 g ~ (-1) and a pore volume of 0.505 cm3 g-1.SnO2@PC as a cathode material for lithium batteries. The initial discharge specific capacity of the composite is up to 1803 mAh g ~ (-1), and the specific discharge capacity is up to 1803 mAh / g ~ (-1) at the current density of 0.5 A g ~ (-1). After 300 cycles, the specific capacity is as high as 770 mAh g -1. Secondly, Sn (OH) _ 4 @ chitosan hydrogel was synthesized from chitosan and tin tetrachloride by crosslinking of chitosan and hydrolysis of tin tetrachloride. The SnO2@C composite was obtained by further drying and calcining. The structure and lithium electrical properties of the synthesized materials were characterized and analyzed. The SnO2C anode material showed excellent cyclic stability. The Sno 2C composite material has a capacity of 579.5 mAh g-1 and a capacity retention greater than 90% after 100 charge-discharge cycles at current density of 0.1A g ~ (-1). Thirdly, TiO2/ porous carbon composites (TiO2@PC) were synthesized by using silica gel as template and SnO2@PC as a synthesis method. Morphology characterization and lithium-storage performance test. TiO2@ PC also has large specific surface area and appropriate pore size distribution. TiO2@ PC is used as anode material for lithium ion battery. When the mass ratio of TiO2/ and glucose is 5 / 1, the synthesized electrode material has the best electrochemical performance. That is to say, under the condition of 0.5 A g ~ (-1) current density measurement, the capacity can be kept at 180 mAh g ~ (-1) after 450 times of charge and discharge.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;TM912
[Abstract]:Lithium ion batteries are widely used in mobile devices as energy storage and conversion devices. Electrode materials play an important role in regulating the lithium storage performance of lithium batteries. Graphite, as a traditional cathode material for lithium batteries, has a low specific capacity (372mAhg-1), which can not meet the needs of large capacity batteries. Therefore, it is necessary to develop anode materials with high specific capacity. Metal oxide is a kind of lithium battery anode material with high specific capacity, simple synthesis method, abundant natural resources and low cost. However, there are still many problems. During charge and discharge, the irreversible capacity is large, and the repeated intercalation of lithium ion easily leads to the destruction and pulverization of the electrode material, which makes the capacity of the battery seriously attenuate. In order to solve the above problems, we combine metal oxides with conductive materials, and regulate the microstructure and porous properties of electrode materials to improve the lithium storage performance and structural stability of electrode materials to some extent. In this thesis, the metal oxide nanoparticles / carbon composites were prepared by mild method, and the lithium electrical properties of the composites were studied. In this paper, some new synthetic ideas are proposed. The main contents are as follows: firstly, SnO2/ porous carbon composites (SnO2@PC) were synthesized using silica gel as template. Silica gel immobilized glucose and SnO2 nanoparticles to a certain extent, which ensured the dispersion of SnO2 nanoparticles. After calcination, SiO2 could be used as a template for SnO2@PC. The synthesized SnO2@PC composite is a bulk porous structure with a specific surface area of 236.22 m2 g ~ (-1) and a pore volume of 0.505 cm3 g-1.SnO2@PC as a cathode material for lithium batteries. The initial discharge specific capacity of the composite is up to 1803 mAh g ~ (-1), and the specific discharge capacity is up to 1803 mAh / g ~ (-1) at the current density of 0.5 A g ~ (-1). After 300 cycles, the specific capacity is as high as 770 mAh g -1. Secondly, Sn (OH) _ 4 @ chitosan hydrogel was synthesized from chitosan and tin tetrachloride by crosslinking of chitosan and hydrolysis of tin tetrachloride. The SnO2@C composite was obtained by further drying and calcining. The structure and lithium electrical properties of the synthesized materials were characterized and analyzed. The SnO2C anode material showed excellent cyclic stability. The Sno 2C composite material has a capacity of 579.5 mAh g-1 and a capacity retention greater than 90% after 100 charge-discharge cycles at current density of 0.1A g ~ (-1). Thirdly, TiO2/ porous carbon composites (TiO2@PC) were synthesized by using silica gel as template and SnO2@PC as a synthesis method. Morphology characterization and lithium-storage performance test. TiO2@ PC also has large specific surface area and appropriate pore size distribution. TiO2@ PC is used as anode material for lithium ion battery. When the mass ratio of TiO2/ and glucose is 5 / 1, the synthesized electrode material has the best electrochemical performance. That is to say, under the condition of 0.5 A g ~ (-1) current density measurement, the capacity can be kept at 180 mAh g ~ (-1) after 450 times of charge and discharge.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;TM912
【相似文献】
相关期刊论文 前10条
1 施庆和;氧化物[J];化学世界;1959年10期
2 R.M.Lum.L.Seibles ,R.P.Jones ,余耀华;添加金属氧化物对已增塑聚氯乙烯的预燃高温裂解化学的效应[J];聚氯乙烯;1982年03期
3 大河内春乃;白木;;化学试剂基础知识讲座 八、金属和金属氧化物[J];化学试剂;1985年02期
4 王岳 ,余楚蓉;金属氧化物的制造方法[J];有色冶炼;1989年05期
5 吴水清;;不合格金属氧化物的退除方法[J];表面技术;1990年05期
6 刘先曙;密封的金属氧化物-储氢电池的生产工艺[J];兵器材料科学与工程;1991年11期
7 C.P.J.VANVUUREN;J.J.BODENSTEIN;M.SCIARONE;P.KESTENS;孙继光;;人工合成铬铁矿在不同金属氧化物下的热分析研究[J];铁合金;1993年04期
8 ;一步生产金属氧化物等微细粉体的新设备[J];现代化工;1999年09期
9 陆军;;甲烷与金属氧化物反应的探讨[J];化学教育;1993年03期
10 张艳辉,田彦文,邵忠财;多形态金属氧化物晶体的制备[J];材料与冶金学报;2005年03期
相关会议论文 前10条
1 马臻;任瑜;卢岩斌;Peter G.Bruce;;介孔过渡金属氧化物催化脱除环境污染物[A];第六届全国环境化学大会暨环境科学仪器与分析仪器展览会摘要集[C];2011年
2 櫖恅i，
本文编号：2175496
本文链接：https://www.wllwen.com/kejilunwen/dianlidianqilunwen/2175496.html
