共查询到18条相似文献,搜索用时 218 毫秒
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随着新能源产业和储能产业的快速发展,二次电池的安全性和能量密度要求越来越高.而传统的液态锂电池使用易燃的电解液,所以存在较大的安全隐患.因此固态锂电池由于其较高的安全性和能量密度受到越来越多人的关注.目前困扰固态电池应用的主要问题是其离子电导率和电极电解质界面问题.固态电解质是固态电池的关键材料.因此开发高离子电导率的固态电解质是开发固态电池的关键.在本工作中,作者成功通过旋涂法制备聚乙二醇-聚丙烯腈-聚甲基丙烯酸甲酯(PEO-PAN-PMMA)凝胶电解质.PEO-PAN-PMMA聚合物薄膜为均匀透明的,具有较高的吸附率,且热稳定性较好,在380℃下保持稳定.通过浸泡电解液可以得到性能优异的凝胶电解质.该凝胶电解质具有较高的离子电导率,室温离子电导率为0.4 mS/cm,而且电化学窗口较宽,在0~4.2 V之间化学性能较为稳定,界面稳定性较好.组装成Li//PEO-PAN-PMMA凝胶电解质//LiCoO2电池之后,正极首圈放电容量为129.8 mAh/g,循环100周,正极放电容量剩余119.51 mAh/g,在0.1 C、0.2 C、0.5 C和1 C倍率下循环,正极放电容量分别为129.8 mAh/g,99.5 mAh/g,86.1 mAh/g和64 mAh/g. 相似文献
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以石油沥青为碳源, 在空气中将其加热到450 ℃制备出纳米碳球(CNBs), 经1500 ℃氮气气氛中加热纳米碳球3 h后得到高温处理的纳米碳球(H-CNBs). 采用扫描电镜、透射电镜、X射线衍射、拉曼光谱和红外光谱对所制备的产物进行了结构表征. 结果表明: 制得的CNBs的粒径在50~80 nm之间, 石墨化程度不高, H-CNBs粒径没有改变但石墨化程度有所提高, 推测了CNBs的形成机理. 用恒流充放电测试分别对CNBs和H-CNBs的电化学性能进行了研究, 在电流密度为1 C时, 其首次放电比容量和经过100圈之后的放电比容量分别为1260 mAh/g和500 mAh/g, 413 mAh/g和200 mAh/g之上, 同时这两种纳米碳球的首次充放电的库伦效率较低, 分别经过10圈和30圈后可以稳定在98%左右. CNBs在经历0.1 C, 1 C, 5 C, 10 C循环回到0.1 C时, 容量几乎完全恢复. 相似文献
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将棕榈纤维经过炭化和氢氧化钾活化制备高度有序的管状碳材料(OCT),并且将其应用于锂硫电池。所制备的OCT具备高的比表面积和大的孔体积,可以有效地储存硫,合成方法简单且成本较低。同时,所制备的S@OCT复合物呈现出优异的电化学性能。载硫量为65%(w/w)的S@OCT复合材料在0.2C(1C=1 672 mA·g-1)的倍率下库伦效率接近于100%,其首圈容量高达1 255.2 mAh·g-1(1.8 mAh·cm-2),并且100圈后容量保持在756.9 mAh·g-1(1.09 mAh·cm-2)。使用5C的大电流测试时,其首圈容量达到了649.1 mAh·g-1(0.93 mAh·cm-2),且在100圈后容量保持在504.2 mAh·g-1(0.72 mAh·cm-2)。 相似文献
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高比能LiFePO4的制备及性能研究 总被引:1,自引:0,他引:1
应用液相沉淀法-固相烧结法制备高密度的LiFePO4/C及纯相LiFePO4.X射线衍射、扫描电镜、傅立叶红外光谱仪、电化学性能测试表明:该样品具有单一的橄榄石结构和3.4 V左右的放电平台,掺碳的LiFe-PO4具有更优良的性能,粒度较小粒径分布均匀,振实密度达1.46 g/cm3,0.1C首次放电比容量为144.6mAh/g,循环20次后容量保持率为93.2%,1C倍率首次放电比容量为133.5 mAh/g,循环20次后容量下降8.76%. 相似文献
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由单质硫与碳纳米管合成一种新型含碳复合材料.XRD、SEM、BET比表面和孔径分布表征观察硫-碳纳米管复合材料,循环伏安法和电池充放电测试材料的电化学性能.结果表明:以硫-碳纳米管作正极组装的2016型扣式电池有较好的电化学性能,其初始放电比容量达680mAh/g(室温),30次循环放电比容量仍稳定在500mAh/g. 相似文献
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锂-硫电池具有高的理论质量/体积能量密度,因而成为最具发展潜力的高比能二次电池体系. 然而,由于硫载体通常采用轻质的碳纳米材料,导致硫基复合材料的振实密度和体积比容量均偏低,制约了电池体积能量密度的提升. 本文尝试采用具有高密度特征的钴酸锂(LiCoO2)作为硫的载体材料,以构筑高振实密度的硫基复合材料,进而提高硫正极的体积比容量. 研究显示,LiCoO2对可溶性多硫化物具有较强的吸附作用,能够促进硫的电化学转化,因而提高了硫的活性物质利用率和循环稳定性. 同时,由于具有高的振实密度(1.90 g·cm-3),S/LiCoO2复合材料的首周体积比容量高达1750.5 mAh·cm-3,是常规硫/碳复合材料的2.2倍. 因此,本文利用具有高密度特征的LiCoO2作为硫载体来提升硫复合材料的体积比容量,有助于实现锂-硫电池的高体积能量密度. 相似文献
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以富含植物蛋白的豆浆作为碳源, 以FePO4·4H2O和LiOH·H2O为原料, 采用流变相方法合成了锂离子电池正极材料LiFePO4/C. X射线衍射(XRD)和扫描电子显微镜(SEM)的表征结果显示, 样品具有良好的结晶性能, 平均粒径约200 nm, 颗粒表面有均匀网络状的碳包覆. 充放电循环研究结果表明: LiFePO4/C具有稳定的电化学循环性能, LiFePO4/C正极材料在0.1C倍率下首次放电比容量达到156 mAh·g-1, 首次充放电效率达到98.7%; 循环40次后, 放电比容量为149 mAh·g-1, 电池容量保持率在95%以上, 1C倍率下首次放电比容量达到134.7 mAh·g-1, 显示出较高的电化学容量和优良的循环稳定性. 相似文献
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A novel synthetic route for LiFePO_4/C cathode materials by addition of starch for lithium-ion batteries 总被引:1,自引:0,他引:1
Shao Hua Luo Zi Long Tang Jun Biao Lu Zhong Tai Zhang State Key Laboratory of New Ceramics Fine Processing Department of Materials Science Engineering Tsinghua University Beijing China Graduate School at Shenzhen Tsinghua University Shenzhen China 《中国化学快报》2007,18(2):237-240
LiFePO4/Carbon composite cathode material was prepared using starch as carbon source by spray-pelleting and subsequent pyrolysis in N2. The samples were characterized by XRD, SEM, Raman, and their electrochemical performance was investigated in terms of cycling behavior. There has a special micro-morphology via the process, which is favorable to electrochemical properties. The discharge capacity of the LiFePO4.C composite was 170 mAh g-1, equal to the theoretical specific capacity at 0.1 C rate. At 4 C current density, the specific capacity was about 80 mAh g-1, which can satisfy for transportation applications if having a more flat discharge flat. 相似文献
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Zengjie Fan Dr. Bing Ding Hongshuai Guo Minyuan Shi Yadi Zhang Shengyang Dong Dr. Tengfei Zhang Prof. Dr. Hui Dou Prof. Dr. Xiaogang Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(45):10710-10717
Lithium–sulfur (Li–S) batteries are considered to be one of the most promising energy storage systems owing to their high energy density and low cost. However, their wide application is still limited by the rapid capacity fading. Herein, polydopamine (PDA)-coated N-doped hierarchical porous carbon spheres (NPC@PDA) are reported as sulfur hosts for high-performance Li-S batteries. The NPC core with abundant and interconnected pores provides fast electron/ion transport pathways and strong trapping ability towards lithium polysulfide intermediates. The PDA shell could further suppress the loss of lithium polysulfide intermediates through polar–polar interactions. Benefiting from the dual function design, the NPC/S@PDA composite cathode exhibits an initial capacity of 1331 mAh g−1 and remains at 720 mAh g−1 after 200 cycles at 0.5 C. At the pouch cell level with a high sulfur mass loading, the NPC/S@PDA composite cathode still exhibits a high capacity of 1062 mAh g−1 at a current density of 0.4 mA cm−2. 相似文献
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将氧化亚硅,铝和石墨经过2步球磨盐酸刻蚀处理,再包覆碳,可制得纳米孔-S i/G/C复合材料,其比容量高达600 mAh/g,电化学循环性能稳定,但首次放电效率较低.氧化亚硅和铝球磨后再经高温热处理,可以促使氧化亚硅完全还原.高温下A l2O3产物的晶型结构由γ相转为稳定难溶的α相,硅/A l2O3复合材料难以刻蚀制孔,而硅/A l2O3/G/C复合材料则显示较高的首次放电效率但循环稳定性较差. 相似文献
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Dual Protection of Sulfur by Carbon Nanospheres and Graphene Sheets for Lithium–Sulfur Batteries 下载免费PDF全文
Dr. Bei Wang Yanfen Wen Delai Ye Dr. Hua Yu Dr. Bing Sun Prof. Guoxiu Wang Dr. Denisa Hulicova‐Jurcakova Prof. Lianzhou Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(18):5224-5230
Well‐confined elemental sulfur was implanted into a stacked block of carbon nanospheres and graphene sheets through a simple solution process to create a new type of composite cathode material for lithium–sulfur batteries. Transmission electron microscopy and elemental mapping analysis confirm that the as‐prepared composite material consists of graphene‐wrapped carbon nanospheres with sulfur uniformly distributed in between, where the carbon nanospheres act as the sulfur carriers. With this structural design, the graphene contributes to direct coverage of sulfur to inhibit the mobility of polysulfides, whereas the carbon nanospheres undertake the role of carrying the sulfur into the carbon network. This composite achieves a high loading of sulfur (64.2 wt %) and gives a stable electrochemical performance with a maximum discharge capacity of 1394 mAh g?1 at a current rate of 0.1 C as well as excellent rate capability at 1 C and 2 C. The improved electrochemical properties of this composite material are attributed to the dual functions of the carbon components, which effectively restrain the sulfur inside the carbon nano‐network for use in lithium–sulfur rechargeable batteries. 相似文献
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不同碳源对LiFePO4/C复合正极材料性能的影响 总被引:6,自引:1,他引:6
采用固相反应法在惰性气氛下合成了橄榄石型LiFePO4/C复合正极材料. 采用XRD, SEM和激光粒度分布(LSD)以及电化学测试等手段对目标材料进行了结构表征和性能测试. 考察了葡萄糖、乙炔黑以及石墨等不同碳源对目标材料性能的影响. 结果表明, 以葡萄糖作为碳源的正极材料具有优良的电化学性能, 首次放电比容量达142.5 mAh/g, 循环30次后, 容量衰减只有2.5%. 分析了不同碳源对目标材料性能影响的原因. 相似文献
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Bingbing Deng Lian Shen Yangai Liu Tao Yang Manshu Zhang Renjie Liu Zhaohui Huang Minghao Fang Xiaowen Wu 《中国化学快报》2017,28(12):2281-2284
A novel porous silicon was synthesized through a magnesiothermic reduction method of molecular sieve for the first time, the porous silicon was used as anode material, which shows a high initial specific capacity of 2018.5 mAh/g with current density of 0.1 A/g. 相似文献