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1.
纳米碳管作为锂离子电池负极材料的研究 总被引:4,自引:0,他引:4
将两种纳米碳管材料作为锂离子电池负极材料,对其嵌锂行为进行了初步研究。两种材料的首次不可逆容量都很大,这被认为是与电解质在电极材料表面的电化学还原生成的SEI膜有关。对于两种纳米碳管而言,nmcl的不可逆容量远远大于nmc2的不可逆容量,其主要原因是由于nmc1比nmc2的比表面积大。 相似文献
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以硅粉、镁粉和葡萄糖为原料,采用高温固相烧结工艺及水热法制备了循环性能优异的锂离子电池多孔硅/碳复合负极材料.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对样品物相和微观形貌进行表征,研究了无定形碳包覆量对产物电化学性能的影响.无定形碳的存在,不仅对多孔硅粉的三维孔隙结构起到了支撑作用,也可有效改善复合材料的导电性能并有效缓冲电化学嵌/脱锂过程中多孔硅颗粒所产生的体积效应.电化学性能测试表明,10次循环后,多孔硅/碳复合负极材料平均每周次容量衰减为0.41%,100次循环后其可逆容量仍可维持在608.7mA·h/g. 相似文献
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采用了一种工业副产品的纳米碳粉作为锂离子电池的负极材料,对纳米碳粉进行了提纯,测定了纳米碳粉的纯度,并对提纯后的纳米碳粉进行了电化学嵌锂性能的研究·充放电实验结果表明,该碳材料首次放电比容量为358 3mA·h/g,首次循环可逆容量为336 4mA·h/g,循环9次后可逆容量保持率为76 1%·TEM观察纳米碳粉的形貌,表明纳米碳粉为球形,直径在30nm左右;XRD测定纳米碳粉的结构,纳米碳粉的d002值介于石墨和软碳材料的d002值之间,为0 3481nm· 相似文献
4.
采用化学气相沉积法,通过在纳米硅表面原位制备碳层而获得具有坚固核壳结构的nano-Si@C锂离子电池负极材料,该材料能有效克服硅负极在充放电过程中出现的体积变化大和电导率低的问题.实验结果表明,nano-Si@C具有优良的电化学性能,首次库伦效率为87.0%,循环100次仍能保持高比容量(1133 mA·h·g-1)和高容量保持率.循环前后的透射电子显微镜(transmission electron microscopy,TEM)结果证明,紧密坚固的核壳结构使nano-Si@C在充放电过程中保持较好的结构稳定性,有利于电极的循环稳定. 相似文献
5.
采用化学气相沉积法,通过在纳米硅表面原位制备碳层而获得具有坚固核壳结构的nano-Si@C锂离子电池负极材料,该材料能有效克服硅负极在充放电过程中出现的体积变化大和电导率低的问题.实验结果表明,nano-Si@C具有优良的电化学性能,首次库伦效率为87.0%,循环100次仍能保持高比容量(1133 mA·h·g-1)和高容量保持率.循环前后的透射电子显微镜(transmission electron microscopy,TEM)结果证明,紧密坚固的核壳结构使nano-Si@C在充放电过程中保持较好的结构稳定性,有利于电极的循环稳定. 相似文献
6.
锂离子电池负极热解碳材料的研究 总被引:5,自引:0,他引:5
用正交试验设计和极差、方差分析的方法,研究了热解酚醛树脂碳材料,该材料第1周放电容量为360mAh/g,充电容量为145mAh/g,充放效率为40.3% ̄80.4%,嵌入深度为0.97,符合锂离子二次电池负极材料的应用要求。并在最优条件下对几种聚合物或有机混合物进行了热解,获得的碳材料具有较优的充放电性能,其中沥青和掺杂磷的沥青的热解碳材料具有优良的嵌锂充放电性能,非常适宜用作实际的锂离子二次电池 相似文献
7.
以葫芦科丝瓜藤蔓为前驱体,通过高温热解碳化制备具有多级孔结构的硬碳材料;采用扫描电子显微镜、X射线衍射、透射电子显微镜和氮气吸附-脱附等方法,对制备的硬碳材料进行形貌和结构分析;采用循环伏安和恒流充放电等测试方法,对制备的硬碳材料的储锂电化学性能进行分析.结果表明:丝瓜藤蔓衍生的硬碳材料富含微孔、介孔多级孔结构,在一定... 相似文献
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以CoSO4·6H2O和NaOH为原料,采用共沉淀法,在一定温度下反应一段时间得到深棕色产物.利用X射线衍射(XRD),透射电镜(TEM),热分析(TG-DTA),恒流充放电测试等方法对所产物结构,形貌,大小等进行分析表征及电化学性能测试.实验结果表明,产物为分散均匀的200nm CoOOH颗粒,且该材料作为锂离子电池负极材料,首圈放电容量达到2 100mAh·g-1,循环20圈后,放电容量保持800mAh·g-1.此方法合成的纳米尺寸的CoOOH作为锂离子电池负极材料具有较好的电化学性能. 相似文献
10.
锂离子电池纳米负极材料的研究和开发 总被引:1,自引:0,他引:1
综述了纳米材料在负极材料方面的最新研究和开发进展,主要包括纳米金属及纳米合金、纳米氧化物、碳纳米管、具有纳米孔结构的无定形炭材料和天然石墨.由于纳米材料的特有性能,它们的可逆容量均高于目前商品化的负极材料.纳米合金负极材料的实业化存在问题,特别是循环稳定性.碳纳米管则由于制备和纯化,成本过高,规模化生产不容易实施,同时理论方面也有待于进一步的研究,以期提高其电化学性能.具有纳米孔的无定形炭材料的制备温度低,而且容量也比较高,但是对于产业化而言,循环性能和电压滞后现象有待于改进.具有纳米孔的天然石墨负极材料不仅容量高、制备比较简单、成本低,而且具有良好的循环性能,可望达到产业化的要求. 相似文献
11.
Modified disordered carbon prepared from 3,4,9,10-perylenetetracarboxylic dianhydride as an anode material for Li-ion batteries
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Fei-biao Chen Bo-rong Wu Yun-kui Xiong Wei-lin Liao Dao-Bin Mu Feng Wu 《矿物冶金与材料学报》2015,22(2):203-209
To prepare an anode material for Li-ion batteries with high discharge capacity and good cycling stability, disordered carbon (DC) formed by calcinations of 3,4,9,10-perylenetetracarboxylic dianhydride was modified via an acid treatment using a mixture of HNO3 and H2SO4. The modified disordered carbon (MDC) was characterized by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET) analysis, and scanning electron microscopy (SEM). FTIR spectra confirm the successful introduction of carbonyl groups onto the DC surface. Some pores appear in the columnar structure of MDC, as observed in SEM micrographs. Li+ ions intercalation/deintercalation is facilitated by the modified morphology. Electrochemical tests show that the MDC exhibits a significant improvement in discharge capacity and cycling stability. These results indicate that the MDC has strong potential for use as an anode material in Li-ion batteries. 相似文献
12.
Dan Wang Qun Ma Kang-hui Tian Chan-Qin Duan Zhi-yuan Wang Yan-guo Liu 《矿物冶金与材料学报》2021,28(10):1666-1674
Ultrafine nano-scale Cu2Sb alloy confined in a three-dimensional porous carbon was synthesized using NaCl template-assisted vacuum freeze-drying followed by high-temperature sintering and was evaluated as an anode for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). The alloy exerts excellent cycling durability (the capacity can be maintained at 328.3 mA·h·g?1 after 100 cycles for SIBs and 260 mA·h·g?1 for PIBs) and rate capability (199 mA·h·g?1 at 5 A·g?1 for SIBs and 148 mA·h·g?1 at 5 A·g?1 for PIBs) because of the smooth electron transport path, fast Na/K ion diffusion rate, and restricted volume changes from the synergistic effect of three-dimensional porous carbon networks and the ultrafine bimetallic nanoalloy. This study provides an ingenious design route and a simple preparation method toward exploring a high-property electrode for K-ion and Na-ion batteries, and it also introduces broad application prospects for other electrochemical applications. 相似文献
13.
Sodium ion(Na+)batteries have attracted increased attention for energy storage owing to the natural abundance and low cost of sodium.Herein,we report the synthesis of mesoporous carbon with large pores as anode for Na-ion batteries.The mesoporous carbon was obtained by carbonization and dense packing of 50 nm resorcinol and formaldehyde spheres synthesized through an extension Sto¨ber method.Our work demonstrates that replacement of lithium by sodium using large pore carbon as anode might offer an alternative route for rechargeable batteries. 相似文献
14.
表面修饰的天然石墨用作锂离子电池嵌锂阳极 总被引:2,自引:0,他引:2
针对天然石墨阳极存在的首次充放电效率低这一应用问题,提出了采用聚合物表面修饰石墨的新方法.结果发现:通过在天然石墨表面修饰聚二甲基硅氧烷,加速了石墨阳极表面钝化膜的形成,降低了电极第一周充放电时的不可逆容量损失,从而提高了电极的首次充放电效率.当石墨表面的聚二甲基硅氧烷修饰量为5%时,电极在保持可逆容量基本不变的情况下,第一周充放电效率提高了13%.此外修饰石墨电极的循环性能也得到了显著改善. 相似文献
15.
T. Zhang L.J. Fu J. Gao Y. P. Wu H.Q. Wu 《复旦学报(自然科学版)》2005,44(5):903-904
Silicon has been regarded as one of the most promising anode materials for Li-ion batteries. Its theoretical capacity (4 000 mAh/g) is much higher than that of the commercialized graphite (372 mAh/g). However, the cycle performance of silicon is poor due to the severe volume expansion and shrinkage during Li^+ insertion/extraction which results in pulverization of Si particles, eventually losing its Li^+ storage ability. To solve this problem, nanosized Si particles were utilized and achieved a partial improvement by reducing the absolute volume change. Nevertheless, a new problem was encountered with nanosized material that small Si particles were aggregated to be larger one during Li^+ insertion/extraction, and then pulverized again. In this work, we have succeeded to improve the cycle performance of nanosized Si particles by synthesis of carbon coated silicon nanopartiele. 相似文献
16.
综述了锂离子电池锑基负极材料——金属锑簿膜、锑基合金、锑基复合氧化物的研究进展,重点介绍了锑基合金材料的不同制备方法,并阐述了锑基负极材料的研究进展与开发前景。 相似文献
17.
Spinel lithium titanate(Li_4Ti_5O_(12)) has the advantages of structural stability, however it suffers the disadvantages of low lithium-ion diffusion coefficient as well as low conductivity. In order to solve issues,we reported a simple method to prepare carbon-coated Li_4Ti_5O_(12)/CNTs(C@Li_4Ti_5O_(12)/CNTs) using stearic acid as surfactant and carbon source to prepare carbon coated nanosized particles. The obtained Li_4Ti_5O_(12) particles of 100 nm in size are coated with the carbon layers pyrolyzed from stearic acid and dispersed in CNTs matrix homogeneously. These results show that the synthesized C@Li_4Ti_5O_(12)/CNTs material used as anode materials for lithium ion batteries, presenting a better high-rate performance(147 m Ahg~(-1)at20 C). The key factors affecting the high-rate properties of the C@Li_4Ti_5O_(12)/CNTs composite may be related to the synergistic effects of the CNTs matrix and the carbon- coating layers with conductivity enhancement. Additionally, the amorphous carbon coating is an effective route to ameliorate the rate capability of Li_4Ti_5O_(12)/CNTs. 相似文献
18.
Aromatic carbon coated tin composites (A/Sn) have been prepared by thermal decomposition of the stannous 1,8-naphthalenedicarboxylate precursors, which is a reformative preparation method. Sugar carbon coated tin composites (S/Sn) also are prepared as a contrast with the A/Sn composites. The morphology and composition of the products were characterized by Scanning Electricity Microscopy (SEM) and X-Ray Diffraction (XRD). Their electrochemical performance as anode materials for lithium ion batteries were investigated; the results indicated that these materials exhibited good performance, and the cycle stability of A/Sn composites is especially superior to the S/Sn composites due to its special carbon resource. 相似文献
19.
Zheng Liu Yuri G. Andreev A. Robert Armstrong Sergio Brutti Yu Ren Peter G. Bruce 《自然科学进展(英文版)》2013,23(3):235-244
Reducing the dimensions of electrode materials from the micron to the nanoscale can have a profound influence on their properties and hence on the performance of electrochemical devices,e.g.Li-ion batteries,that employ such electrodes.TiO2(B) has received growing interest as a possible anode for Li-ion batteries in recent years.It offers the possibility of higher energy storage compared with the commercialized Li4Ti5O12.Bulk,nanowire,nanotube,and nanoparticle morphologies have been prepared and studied.However,to date these materials have not be compared in one article.In the current review we first summarize the different synthesis methods for the preparation of nanostructured TiO2(B);then present the effects of size and shape on the electrochemical properties.Finally TiO2(B) with nanometer dimensions exhibit a higher capacity to store Li,regardless of rate,due to structural distortions inherent at the nanoscale. 相似文献