以多孔铜为集流体制备Cu6Sn5合金负极及其性能

以氢气泡为动力学模板电沉积获得多孔铜,并通过热处理增强其结构稳定性.进一步将多孔铜作为基底通过电沉积制备Cu-Sn合金负极.XRD结果给出其组成为Cu6Sn5合金,扫描电子显微镜(SEM)观察到Cu6Sn5合金电极为三维(3D)多孔结构.充放电结果指出,Cu6Sn5合金电极具有较好的充放电性能,其首次放电(嵌锂)和充电(脱锂)容量分别为735和571 mAh·g-1,并且具有较好的容量保持率.运用电化学阻抗谱研究了Cu6Sn5合金电极在商业电解液中的界面特性.     

以多孔铜为集流体制备Cu6Sn5合金负极及其性能

以氢气泡为动力学模板电沉积获得多孔铜, 并通过热处理增强其结构稳定性. 进一步将多孔铜作为基底通过电沉积制备Cu-Sn合金负极. XRD结果给出其组成为Cu6Sn5合金, 扫描电子显微镜(SEM)观察到Cu6Sn5合金电极为三维(3D)多孔结构. 充放电结果指出, Cu6Sn5合金电极具有较好的充放电性能, 其首次放电(嵌锂)和充电(脱锂)容量分别为735和571 mAh·g-1, 并且具有较好的容量保持率. 运用电化学阻抗谱研究了Cu6Sn5合金电极在商业电解液中的界面特性.     

锂离子电池用纳米Sn/SnSb合金三维复合负极的制备及性能

采用多步电沉积法制备的三维多孔铜箔作为集流体、低温液相化学还原法制备的纳米Sn/SnSb 合金作为负极材料, 制备出一种新型三维多孔结构的纳米Sn/SnSb合金复合负极. 通过与普通负极电化学性能的对比实验发现, 这种新型三维复合负极具有如下优点: 三维多孔网络结构提高了负极活性材料与集流体之间的结合力, 使不含粘结剂电极的制备成为可能; 有效缓解了高容量负极活性材料在充放电过程中的体积膨胀, 提高了负极活性材料的循环性能, 当循环到第30周时, 普通负极剩余容量为初始容量的33%, 而三维复合负极剩余容量为初始容量的41%; 三维铜箔集流体的特殊结构为高容量负极活性材料提供了一个良好的导电环境, 使电极反应进行得更加完全, 从而获得了更高的电极比容量, 普通负极初始容量为480 mAh·g-1, 而三维复合负极达到了800 mAh·g-1. 纳米Sn/SnSb合金三维复合负极良好的电化学性能为锂离子电池负极结构的设计开发提供了新的思路.     

电化学阻抗谱法研究温度对三维多孔Cu6Sn5合金电极嵌锂过程的影响

采用氢气泡为动力学模板电沉积获得多孔铜,通过热处理增强其结构稳定性,并以该多孔铜为基底电沉积获得三维多孔Cu6Sn5合金电极.采用循环伏安法研究了三维多孔Cu6Sn5合金电极的嵌/脱锂电位.采用电化学阻抗谱研究了三维多孔Cu6Sn5合金电极在不同温度下的首次嵌锂过程.结果显示,在主要的嵌锂区间内,三维多孔Cu6Sn5合...     

三维多孔Sn-Co合金负极制备及其电化学性能研究

采用化学镀方法制备三维多孔铜.以其作为集流体,借助电沉积制备三维多孔Sn-Co合金电极.X-射线衍射(XRD),扫描电镜(SEM)分析表明,以多孔铜为集流体制备的SnCo合金电极主要存在CoSn2相和纯Sn相,为三维多孔结构.充放电结果显示,三维结构SnCo合金电极比平面铜集流体上镀得的SnCo合金电极表现出更优越的充放电性能.前者的首次放电(嵌锂)容量为636.3mAh/g,充电(脱锂)容量为528.7mAh/g,首次库仑效率为83.1%,70周后容量为529.5mAh·g-1,保持率为82.6%.此外,还应用电化学阻抗初步研究了三维Sn-Co合金电极在充放电过程发生的嵌脱锂过程.     

熔体旋淬Ml(NiCoMnAl)_5贮氢合金的组织结构与电化学特性

对比研究了熔体旋淬和常规熔铸Ml(NiCoMnAl) 5 贮氢合金的组织结构和电化学特性。SEM和XRD分析表明 :熔体旋淬合金为细小的柱状晶粒组成 ,随着旋淬速度的增加 ,晶粒越来越细小 ,成分越来越均匀 ;它们的晶体结构和铸态一样 ,都为CaCu5 型六方晶体结构 ;随着旋淬速度的增加 ,晶粒主要按 (111) [111]择优取向生长。电化学测试表明 :旋淬态合金电极初始容量都大于 2 10mAh·g - 1 ,活化性能好 ,经两次充放电循环 ,就可达到最大放电容量。旋淬速度 10m·s- 1 的合金电极的最大放电容量 (2 94mAh·g- 1 )与铸态合金电极的最大容量相当 ,所有旋淬速度的合金电极充放电循环稳定性优于铸态合金电极。在 6 0 0mA·g- 1 电流密度下 ,旋淬速度 10m·s- 1 的合金电极充电 45min就能达到其最大容量的 6 5 %左右 ,具有较好的高倍率充放电能力 ,但随着循环次数的增加 ,它的容量稳定性稍次于旋淬速度 40m·s- 1 的合金电极。     

掺杂离子对聚吡咯膜的电化学容量性能的影响

用电化学方法制备了分别以对甲基苯磺酸根(TOS-), 高氯酸根(ClO-4)和氯离子(Cl-)掺杂的聚吡咯(PPy)膜. 用循环伏安(CV)、恒电流充放电和电化学阻抗谱(EIS)等测试了它们的电化学容量性能. 用扫描电镜(SEM)和X射线衍射(XRD)分别研究了这三种PPy膜的形貌和结构. 研究发现, 由于具有疏松多孔的形貌和更有序的分子链结构, PPy-TOS和 PPy-Cl膜具有较好的充放电能力, 在深度充放电时仍具有很小的电化学电阻, 其离子扩散接近理想电容器的离子扩散机理. PPy-Cl(聚合电量2 mAh·cm-2)的比容量在扫描速率为5 mV·s-1时高达270 F·g-1, 扫描速率200 mV·s-1时仍高达175 F·g-1, 特别是, 其比能量高达35.3 mWh·g-1. PPy-TOS由于有质量较大的掺杂离子(TOS-)因而比容量略低(146 F·g-1, 扫描速率5 mV·s-1), 但具有超快速充放电能力, 在扫描速率为200 mV·s-1时, 比容量为123.6 F·g-1, 其比功率高达10 W·g-1. 并且, 两种电极材料均具有稳定的电化学循环性能.     

电化学阻抗谱法研究Cu_6Sn_5合金负极相变过程

以粗糙铜箔为基底,采用一步电沉积法获得Cu-Sn合金,X射线衍射(XRD)测试结果显示其主要为Cu6Sn5合金相.扫描电子显微镜(SEM)测试结果表明该合金表面由大量"小岛"组成,且每个"小岛"上存在大量纳米合金粒子.充放电测试结果表明,以该合金为锂离子电池负极,其初始放电(嵌锂)和充电(脱锂)容量分别为461和405 mAh·g-1.电化学阻抗谱测试结果显示,Cu6Sn5合金电极在阴极极化过程中分别出现了代表固体电解质界面膜(SEI膜)阻抗、电荷传递阻抗和相变阻抗的圆弧,并详细分析了它们的变化规律.     

铜掺杂五氧化二钒的制备及电化学性质

采用沉淀法于300 和600 ℃制备了结晶状的Cu0.04V2O5材料. 扫描电镜显示, 300 ℃时制备的样品具有多孔特征, 而600 ℃时制备的样品具有很高的结晶度. X射线研究表明, 少量铜掺杂不会改变V2O5的正交晶体结构. 红外光谱研究表明, 300 ℃时制备的Cu0.04V2O5样品含有少量水. 热失重分析确定了样品中所含水分是以吸附水的形式存在, 1 mol材料分子吸附水的摩尔数约为0.18 mol. 铜掺杂显著改善了V2O5的结构稳定性, 进而提高了材料的充放电循环性能. 于600 ℃制备的样品在C/5.6倍率下具有160 mAh·g-1的可逆比容量, 但提高放电倍率明显降低了材料的循环性能. 于300 ℃制备的样品在C/5.6倍率时的循环性能不如600 ℃样品, 但该材料在C/1.9倍率时仍具有100 mAh·g-1左右的可逆比容量. 两种材料在电化学性能上的差异与材料的微结构有关. 低温样品在较高放电倍率时良好的循环性能得益于其多孔的微结构, 而高温样品由于其较高的结晶度而表现出优异的低倍率充放电性能.     

多孔炭模板法制备Li4Ti5O12及其嵌锂行为

采用水合氧化钛溶胶为原料, 多孔炭为模板剂, 设计制备了一种新型准纳米晶锂钛复合氧化物, 并用SEM、XRD、恒流充放电及交流阻抗测试表征了材料的形貌、结构和电化学性能. 结果表明, 该氧化物晶粒尺寸约200 nm, 为典型的尖晶石Li4Ti5O12结构. 在0.5C(1C=0.2 mA·cm-2)电流条件下的首次嵌脱锂效率为99.8%, 嵌脱锂电位平坦, 可逆容量为117 mAh·g-1; 当电流从0.5C增至5C时, 其可逆嵌锂容量仍在100 mAh·g-1以上, 容量保持率大于86%, 倍率充放电性能优异. 交流阻抗测试结果表明, 模板剂多孔炭的应用使合成的尖晶石Li4Ti5O12具有更佳的导电性能, 且多孔特征明显.     

电化学阻抗谱法研究Cu6Sn5合金负极相变过程

以粗糙铜箔为基底, 采用一步电沉积法获得Cu-Sn合金, X射线衍射(XRD)测试结果显示其主要为Cu6Sn5合金相. 扫描电子显微镜(SEM)测试结果表明该合金表面由大量“小岛”组成, 且每个“小岛”上存在大量纳米合金粒子. 充放电测试结果表明, 以该合金为锂离子电池负极, 其初始放电(嵌锂)和充电(脱锂)容量分别为461和405 mAh•g－1. 电化学阻抗谱测试结果显示, Cu6Sn5合金电极在阴极极化过程中分别出现了代表固体电解质界面膜(SEI膜)阻抗、电荷传递阻抗和相变阻抗的圆弧, 并详细分析了它们的变化规律.     

Electrodeposition and characterization of assembly of Sn on Cu nanorods for Li-ion microbattery application

Assembly of Sn on Cu Nanorods as anode for Li-ion microbatteries was prepared by a two-step electrodeposition design. Firstly, Cu nanorods arrays were grown on copper substrate by anodic aluminum oxide template-assisted growth method. Then, Sn was deposited onto Cu nanorods arrays by galvanostatic deposition. X-ray diffraction and scanning electron microscopy measurements reveal that Cu nanorod arrays are covered with Sn. Electrochemical performances of prepared electrodes were evaluated by charge/discharge cycle measurement. The assembly of Sn on Cu nanorods electrode exhibited highly reversible specific capacity and superior capacity retention resulting from the three-dimensionally nano-architectured design, which exhibits a large surface area, shortened Li-ion diffusion distance, Cu–Sn alloying, and can accommodate the volume expansion of Sn during cycling. Deposition time is an important parameter for fabricating the assembly of Sn on Cu nanorods electrode with suitable structure and morphology.

     

球形Sn-SnSb合金纳米粒子制备及其储锂性能

锂离子电池Sn负极材料有较高的比容量,但其容量随周期循环急剧衰减. 若Sn与Sb形成SnSb合金可以改善其循环性能. 本文采用有机液相还原方法制备了球形Sn-SnSb合金纳米粒子,其首周期循环充电容量1235.9 mAh·g^-1,放电容量为785.9 mAh·g^-1,经过50周的循环之后其放电容量保持在409.2 mAh·g^-1,表现出较好的循环性能.     

Electrodeposition and characterization of assembly of Sn on Cu nanorods for Li-ion microbattery application

Assembly of Sn on Cu Nanorods as anode for Li-ion microbatteries was prepared by a two-step electrodeposition design. Firstly, Cu nanorods arrays were grown on copper substrate by anodic aluminum oxide template-assisted growth method. Then, Sn was deposited onto Cu nanorods arrays by galvanostatic deposition. X-ray diffraction and scanning electron microscopy measurements reveal that Cu nanorod arrays are covered with Sn. Electrochemical performances of prepared electrodes were evaluated by charge/discharge cycle measurement. The assembly of Sn on Cu nanorods electrode exhibited highly reversible specific capacity and superior capacity retention resulting from the three-dimensionally nano-architectured design, which exhibits a large surface area, shortened Li-ion diffusion distance, Cu?CSn alloying, and can accommodate the volume expansion of Sn during cycling. Deposition time is an important parameter for fabricating the assembly of Sn on Cu nanorods electrode with suitable structure and morphology.     

Electrodeposition and electrochemical properties of novel ternary tin–cobalt–phosphorus alloy electrodes for lithium-ion batteries

Porous Sn–Co–P alloy with reticular structure were prepared by electroplating using copper foam as current collector. The structure and electrochemical performance of the electroplated porous Sn–Co–P alloy electrodes were investigated in detail. Experimental results illustrated that the porous Sn–Co–P alloy consists of mainly SnP_0.94 phase with a minor quantity of Sn and Co₃Sn₂. Galvanostatic charge–discharge tests of porous Sn–Co–P alloy electrodes confirmed its excellent performances: at 50th charge–discharge cycle, the discharge specific capacity is 503 mAh g^?1 and the columbic efficiency is as high as 99%. It has revealed that the porous and multi-phase composite structure of the alloy can restrain the pulverization of electrode in charge/discharge cycles, and accommodate partly the volume expansion and phase transition, resulting in good cycleability of the electrode.     

Fabrication and electrochemical properties of the Sn–Ni–P alloy rods array electrode for lithium-ion batteries

A new ternary Sn–Ni–P alloy rods array electrode for lithium-ion batteries is synthesized by electrodeposition with a Cu nanorods array structured foil as current collector. The Cu nanorods array foil is fabricated by heat treatment and electrochemical reduction of Cu(OH)₂ nanorods film, which is grown directly on Cu substrate through an oxidation method. The Sn–Ni–P alloy rods array electrode is mainly composed of pure Sn, Ni₃Sn₄ and Ni–P phases. The electrochemical experimental results illustrate that the Sn–Ni–P alloy rods array electrode has high reversible capacity and excellent coulombic efficiency, with an initial discharge capacity and charge capacity of 785.0 mAh g^?1 and 567.8 mAh g^?1, respectively. After the 100th discharge–charge cycling, capacity retention is 94.2% with a value of 534.8 mAh g^?1. The electrode also performs with an excellent rate capacity.