本文選題：鋰離子電池　切入點：負極材料　出處：《南京師范大學》2014年碩士論文　論文類型：學位論文

【摘要】：近幾年來,已經(jīng)商業(yè)化的鋰離子電池負極材料一般是石墨以及各種碳材料。但是隨著便攜式電子設備、電動汽車和儲能裝置的高速發(fā)展,碳基材料低的比容量已經(jīng)不能滿足其要求,因此,迫切需要尋求具有高比容量的新型負極材料。錫基材料具有高的體積和質(zhì)量比容量,被認為在高能量密度和高功率密度鋰離子動力電池中具有良好的潛在應用前景。然而,錫基材料在充放電過程中存在著體積膨脹問題,這會導致電極材料的粉化、失去電接觸以及容量的快速衰減。碳復合的錫基材料具有納米材料和碳復合的優(yōu)勢,有望滿足鋰離子動力電池的需求。 本論文以錫基負極材料為研究內(nèi)容,包括二硫化錫(SnS2)、二氧化錫(Sn02)和錫基合金。以三維介孔碳為載體、Sn納米球和SnCl4/K2Ni(CN)4氰膠為前驅(qū)體,通過簡便的化學反應制備了一系列碳復合的錫基納米材料。由于獨特的結(jié)構(gòu)和組成特性,這些錫基復合納米材料均表現(xiàn)出了較好的儲鋰性能。本論文的主要創(chuàng)新結(jié)果如下： (1)以三維介孔碳為載體,通過簡便的液相化學反應制備出介孔碳負載的SnS2納米片。與純的SnS2相比,介孔碳負載SnS2納米片結(jié)合了SnS2的二維層狀結(jié)構(gòu)和介孔碳的三維多孔結(jié)構(gòu)的優(yōu)勢,因而表現(xiàn)出了較好的容量保持率、較高的比容量和倍率特性。例如,在100mA·g-1的充放電速率下經(jīng)過50次循環(huán),介孔碳負載SnS2納米片的放電比容量保持在428.8mAh·g-1,遠高于純的SnS2負極材料在50次循環(huán)之后的比容量(282.2mAh·g-1)。 (2)以Sn納米球為前驅(qū)體,通過Si02包覆、熱處理、碳包覆以及最后的去除Si02過程制備得到Sn02@C蛋黃-蛋殼結(jié)構(gòu)納米球。與純的Sn02納米球相比,Sn02@C蛋黃-蛋殼結(jié)構(gòu)納米球表現(xiàn)出了較好的容量保持率、較高的比容量和倍率特性。例如,在100mA·g-1的充放電速率下經(jīng)過30次循環(huán),Sn02@C蛋黃-蛋殼結(jié)構(gòu)納米球的放電比容量保持在515.2mAh·g-1;而在500mA·g-1和1A·g-1的高充放電速率下,其放電比容量仍分別高達395.8(?)307.5mAh·g-1。 (3)以SnCl4/K2Ni(CN)4氰膠為前驅(qū)體,通過簡便的液相還原過程及隨后的葡萄糖水熱碳化過程制備得到三維多孔Sn-Ni@C復合納米材料。由于獨特的結(jié)構(gòu)和組成特性,三維納米多孔Sn-Ni@C復合材料表現(xiàn)出了優(yōu)越的循環(huán)性能、高的比容量和倍率特性。例如,在200mA·g-1的充放電速率下經(jīng)過40次循環(huán),其放電比容量不再衰減,保持在440.0mAh·g-1。
[Abstract]:In recent years, cathode materials for lithium ion batteries that have been commercialized have generally been graphite and various carbon materials. But with the rapid development of portable electronic devices, electric vehicles and energy storage devices, The low specific capacity of carbon-based materials can not meet its requirements. Therefore, it is urgent to seek new negative electrode materials with high specific capacity, and tin based materials have high volume and mass specific capacity. It is considered that there are good potential applications in high energy density and high power density lithium-ion power batteries. However, the bulk expansion of tin based materials in charge and discharge process, which will lead to the electrode material powder. Due to the loss of electrical contact and the rapid attenuation of capacity, the carbon composite tin based material has the advantages of nano-material and carbon composite, which is expected to meet the needs of lithium-ion power battery. In this thesis, tin based anode materials, including tin disulfide SNS _ 2, Sn _ 2O _ 2, Sn _ 2O _ 2 and tin based alloys, were used as materials, and three dimensional mesoporous carbon as carrier, Sn nanospheres and SnCl4/K2Ni(CN)4 cyanide were used as precursors. A series of carbon composite tin based nanomaterials have been prepared by simple chemical reaction. Due to their unique structure and composition properties, these tin based composite nanomaterials have good lithium storage properties. The main innovative results of this thesis are as follows:. 1) SnS2 nanoparticles supported on mesoporous carbon were prepared by a simple liquid phase reaction using three-dimensional mesoporous carbon as the carrier. The mesoporous carbon supported SnS2 nanochips combine the advantages of the two-dimensional layered structure of SnS2 and the three-dimensional porous structure of mesoporous carbon, thus showing better capacity retention, higher specific capacity and ratio characteristics. After 50 cycles at the charge / discharge rate of 100mA 路g ~ (-1), the specific discharge capacity of mesoporous carbon supported SnS2 nanoparticles remained at 428.8 mAh 路g ~ (-1), which was much higher than that of pure SnS2 anode material after 50 cycles (282.2 mAh 路g ~ (-1)). Using Sn nanospheres as precursor, Si02 coating, heat treatment, Sn02@C yolk-eggshell structure nanospheres were prepared by carbon coating and final Si02 removal process. Compared with pure Sn02 nanospheres, Sn02C yolk-shell structure nanospheres showed better capacity retention, higher specific capacity and higher specific capacity and ratio properties, for example, compared with pure Sn02 nanospheres, Sn02C yolk-shell structure nanospheres showed better capacity retention, higher specific capacity and higher specific capacity than pure Sn02 nanospheres. At the charge / discharge rate of 100mA 路g-1, the discharge specific capacity of Sn02C yolk-shell structure nanospheres remained at 515.2 mAh 路g-1 after 30 cycles, but at the high charge-discharge rate of 500mA 路g-1 and 1A 路g-1, the discharge specific capacity was still as high as 395.8? 307.5mAh 路g-1. Three dimensional porous Sn-Ni@C composite nanomaterials were prepared by simple liquid phase reduction and subsequent hydrothermal carbonization of glucose using SnCl4/K2Ni(CN)4 cyanide gel as precursor. Three-dimensional nano-porous Sn-Ni@C composites exhibit excellent cycling performance, high specific capacity and rate characteristics. For example, after 40 cycles at a charge / discharge rate of 200mA 路g ~ (-1), the specific discharge capacity of the composite is no longer attenuated and maintained at 440.0 mAh 路g-1.
【學位授予單位】：南京師范大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TB383.1;TM912

【參考文獻】

相關期刊論文 前1條

1 任建國,王科,何向明,姜長印,萬春榮,蒲薇華;鋰離子電池合金負極材料的研究進展[J];化學進展;2005年04期

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本文編號：1591480