共查询到20条相似文献,搜索用时 9 毫秒
1.
2.
3.
4.
Using electrospinning, specially prepared Ti and Sr precursor TiO2/SrTiO3 composite nanofibers were successfully fabricated. This would ensure the close and uniform contact between TiO2 and SrTiO3, which significantly contributes to the electrons transfer at the interface between the two semiconductors with different band gaps. Meanwhile, the long fibrous structure of TiO2/SrTiO3 composite nanofibers would further ease the electron transfer, enlarge the specific surface area, and enhance the light absorption capability thus leading to the improvement of photocatalytic efficiency. Because of the above‐mentioned advantages, the TiO2/SrTiO3 composite nanofibers exhibited higher photocatalytic H2 generation efficiency over bare TiO2 nanofibers in a water/methanol sacrificial reagent system under the irradiation of UV light. 相似文献
5.
采用高温热解法制得Si/C/B2O3复合材料,并用XRD和XPS分析材料的物相结构和组成.以复合材料为锂离子电池电极进行恒流充放电测试,并通过循环伏安曲线和充放电曲线研究了材料的电化学反应特性.结果表明,复合材料中的硼以氧化物的形式存在,材料的可逆容量和电化学循环稳定性较硅/碳材料均有较为明显的提高,900℃条件下热解得到的材料的首次可逆容量为584 mA·h·g-1,复合材料在第40次循环的可逆容量可达到325 mA·h·g-1. 相似文献
6.
随着纳米技术的进步,量子点纳米材料在理论和实验研究方面受到越来越多的关注.由于量子点阵列优异的物理性能与其空间分布的有序性十分相关,空间分布有序量子点阵列的大面积重复性制备已成为高性能纳米光电子器件商业化应用的关键.近几十年来,在量子点空间排列分布有序性的提高、缺陷态的减少、成核位置可控以及大面积重复制备方面人们已做了大量研究.本文主要讨论和综述当前在制备空间分布有序硅/锗(Si/Fe)量子点方面的技术工艺和成果,并展望其未来技术发展思路和方向,希望为今后进一步探索研究大面积空间分布有序Si/Ge量子点阵列的制备提供信息参考. 相似文献
7.
以二氧化锡和导电碳(Super P)为原料,通过高能球磨,采用高温固相法制得锡/碳复合材料作为锂离子电池负极材料。用XRD、SEM进行表征,并进行有关电化学性能测试,首次放电比容量高达566.4 mAh.g-1,循环性能得到了较大改善。 相似文献
8.
以一氧化硅、二氧化锡和导电碳(Super P)为原料,通过高能球磨,加入稀盐酸与糠醇发生聚合反应,再采用高温固相法制得硅/氧化硅/锡/碳复合材料作为锂离子电池负极材料.用 XRD、SEM 进行表征,并进行有关电化学性能测试,首次放电比容量高达 1503 mAh·g<'-1>,循环性能得到了较大改善. 相似文献
9.
Xiao She Peilei Sun Xianghua Yu Qiao Zhang Yanguang Wu Liang Li Yineng Huang Songmin Shang Shouxiang Jiang 《Journal of Inorganic and Organometallic Polymers and Materials》2014,24(5):884-889
The polypyrrole (PPy)/graphene oxide (GO) composite hydrogels with hierarchical porous structures were fabricated by one-step self-assembly method. The static oxidation polymerization of pyrrole monomer in GO aqueous solution resulted in the formation of three-dimensional (3D) PPy/GO composite hydrogels, which consisted of one-dimensional PPy nanofibers and two-dimensional GO nanosheets. The as-prepared composite hydrogels exhibited shrinking–swelling behavior with cycles of suction and water-supplying. The effects of GO nanosheets content on the swelling properties were investigated. Results showed that the well-dispersed GO nanosheets in the hydrogel networks resulted in a significant improvement in water absorbencies of the hydrogels. PPy/GO composite hydrogels exhibited unobvious variation in the water absorbency even in saline solutions. Such excellent properties in water absorbencies endow the conducting 3D PPy/GO composite hydrogels with great potential applications in electrochemical sensors or controlled release. 相似文献
10.
Spinel Electrodes for Lithium Batteries 总被引:8,自引:0,他引:8
Michael M. Thackeray 《Journal of the American Ceramic Society》1999,82(12):3347-3354
This article gives a historical account of the development of spinel electrodes for rechargeable lithium batteries. Research in the late 1970s and early 1980s on high-temperature Li/Fe3 O4 cells led to the evaluation of lithium spinels Li[B2 ]X4 at room temperature (B = metal cation). This work highlighted the importance of the [B2 ]X4 spinel framework as a host electrode structure and the ability to tailor the cell voltage by selection of various B cations. Examples of lithium-ion cells that operate with spinel anode/spinel cathode couples are provided. Particular attention is given to spinels within the solid-solution system Li1+ x Mn2- x O4 (0 lessthan equal to x lessthan equal to 0.33). 相似文献
11.
Jiangliu Zhu Yurong Ren Bo Yang Wenkai Chen Jianning Ding 《Nanoscale research letters》2017,12(1):627
Embedded Si/graphene composite was fabricated by a novel method, which was in situ generated SiO2 particles on graphene sheets followed by magnesium-thermal reduction. The tetraethyl orthosilicate (TEOS) and flake graphite was used as original materials. On the one hand, the unique structure of as-obtained composite accommodated the large volume change to some extent. Simultaneously, it enhanced electronic conductivity during Li-ion insertion/extraction. The MR-Si/G composite is used as the anode material for lithium ion batteries, which shows high reversible capacity and ascendant cycling stability reach to 950 mAh·g?1 at a current density of 50 mA·g?1 after 60 cycles. These may be conducive to the further advancement of Si-based composite anode design. 相似文献
12.
电解液锂盐是锂离子电池的最重要组成部分之一。对现有锂盐进行修饰和合成具有特定性质的新型锂盐是提高锂离子电池性能的有效手段。文章就目前国内外锂离子电池电解液有机锂盐的研究进展进行了综述。在总结这些锂盐开发研究工作共同点的基础上,提出了锂盐的发展方向及其开发思路。 相似文献
13.
14.
15.
锂离子电池负极材料研究进展 总被引:1,自引:0,他引:1
锂离子二次电池是应用和开发前景最好的一种电源,改善和提高锂离子电池电化学性能的关键是选取充放电性能良好的正负极材料。综述了锂离子电池负极材料的研究进展,介绍了碳素材料、锡基负极材料和其他负极材料。指出了今后锂离子二次电池负极材料的发展方向。 相似文献
16.
以Si粉和BN粉为原料,Fe2O3为烧结助剂,采用反应烧结法于1450℃氮气气氛下制备了Si3N4-BN复合材料. 利用XRD研究了不同烧结制度和BN含量下复合材料的物相组成,利用SEM对材料断面形貌进行了观察,并测定了不同BN含量材料的显气孔率、体积密度和常温抗折强度,同时探讨了Fe2O3的助烧机理和b-Si3N4的形成机理. 研究结果表明,当氮化温度为1450℃、保温时间为45 h时,Si可完全氮化,材料中主晶相仅为Si3N4和BN. 随着BN含量的增加,相对密度和常温抗折强度下降,b-Si3N4含量增多. 当BN含量为30%时,其相对密度为73.3%,抗折强度可达52.5 MPa,同时b/a相比为3.4. 相似文献
17.
18.
采用紫外光辐照接枝的方法,在聚丙烯(PP)锂离子电池隔膜表面接枝聚丙烯酸(PAA)。用傅立叶全反射红外光谱(ATR-FTIR)表征隔膜表面PAA的接枝情况,并考察了单体浓度、光照时间对接枝率的影响。此外,采取静态水接触角测试隔膜表面的亲水性,通过测试Gurley值来观察隔膜的透气度,用扫描电子显微镜(SEM)对隔膜表面形貌进行观测。研究了PAA接枝率对隔膜的表面亲水性、形貌、透气度的影响。结果表明,隔膜表面成功地接枝PAA;通过调节反应条件可以得到目标接枝率,改性隔膜的亲水性明显提高,同时不会明显影响隔膜多孔结构,隔膜仍具有较高的透气度。 相似文献
19.
磷酸铁锂锂离子电池正极材料的研究 总被引:1,自引:0,他引:1
锂离子电池是绿色高能可充电池,具有工作电压高、比能量大、自放电小、循环寿命长、无记忆效应、无环境污染等突出优点。本文从磷酸铁锂的结构与性能、材料的制备方法、改性、粒径控制等几方面综述了近年来对橄榄石型磷酸铁锂(LiFePO4)锂离子电池正极材料的研究进展。材料的粒度大小及其分布、离子和电子的传导能力对产品的电化学性能影响很大。在制备时,采用惰性气氛、掺杂导电材料和控制晶粒生长制备粉体是获得性能优良的LiFePO4的有效方法。 相似文献
20.
20 Ah锂离子动力电池倍率放电容量衰减的研究 总被引:1,自引:1,他引:0
20 Ah锂离子动力电池在室温条件下不同倍率的循环性能测试表明,经过2C,3C高倍率循环200周之后的电池容量衰减率为25.58 %和34.85 %,而经过1C循环200周的电池衰减仅为20.28 %.经过3C循环200周的电池内阻在完全放电态时相对于新电池增加了32.9 %.通过对半电池的研究,发现高倍率条件下,负极引起的容量损失占主要地位,通过进一步交流阻抗的研究,得出在高倍率条件下负极SEI膜增厚,导致Li 在负极表面脱嵌阻力增大是引起电池衰减的主要原因. 相似文献