掺杂金属对天然鳞片石墨电化学嵌/脱锂性能的影响

研究化学镀Ni、Cu和混合掺杂Zn处理后天然鳞片石墨的电化学嵌/脱锂性能。结果表明:金属微粒Ni、Cu与Zn的掺入可有效改善天然鳞片石墨的循环性能与大倍率充放电特性,金属微粒有效降低石墨电极内阻、保证石墨颗粒之间紧密的电接触是掺入金属微粒后石墨大倍率充放电性能得到改善的重要原因之一。Ni与Cu微粒改善石墨循环性能的机理与Zn的不同,Cu、Ni通过阻止溶剂化锂离子嵌入维持石墨结构稳定性,来达到提高材料循环性能的目的;金属Zn改善石墨循环性能的原因则可能是嵌锂过程中,Zn锂化所形成Li-Zn合金维持材料表面所形成SEI膜的稳定性。     

汽车动力转向泵试验标准及试验方法研究

在总结和分析当前汽车动力转向泵试验行业标准和相关企业标准中试验项目数量、技术要求和试验方法异同的基础上,结合实际试验经验,从车辆行驶安全、节能等方面考虑,对已有的试验项目进行了有益的补充,并增加了若干必要的试验项目以及转向泵与转向系统其他部件的匹配试验的内容,以期达到进一步完善试验规范、更加客观检验转向泵质量的目的.     

混合酸脱除石油焦中硫的研究

研究了混合酸溶液脱除石油焦中硫的技术。采用单因子法分析了石油焦粒度、混合酸配比、液固比、反应时间和反应温度对脱硫率的影响, 对混合酸脱除石油焦中硫的反应机理进行了初步探讨。通过正交实验确定了混合酸脱除石油焦中硫的最佳条件。结果表明: 使用混合酸可以有效脱除石油焦中大部分硫, 最佳脱硫条件为: 石油焦粒度0.1 mm, 混合酸配比为1.0, 液固比为30∶1, 反应时间为24 h, 反应温度为60 ℃。在此最佳条件下, 最大脱硫率达到63.5%。     

锂空气电池用碳纳米管/钴锰氧化物复合电极材料的制备及电化学性能

采用沉淀法合成了不同钴锰含量的碳纳米管(CNTs)/钴锰氧化物纳米复合材料. 利用XRD、SEM、TEM、BET和FT-IR等方法对材料进行了表征, 考察了不同复合材料对锂空气电池放电及充电过程的影响, 同时对循环性能进行了研究. 结果表明: 钴锰比例为4:0与0:4时, 产物为CNTs/Co₃O₄与CNTs/Mn₃O₄, 钴锰比例为3:1、2:2、1:3时, 产物为CNTs/(Co, Mn)(Co, Mn)₂O₄。产物具有良好的分散性能, 氧化物负载在碳管表面, 其中CNTs/Mn₃O₄的分散性能最好。随着锰含量的增加, 电池的放电性能提高, CNTs/Mn₃O₄的放电电压达到2.92 V。随着钴含量的增加, 电池的充电性能提高, 充电电压最低为3.80 V。钴锰比为3:1时的产物充放电过电势(△V)仅为1.05 V, 5次循环后依然保持着良好的放电性能。     

铝电解槽电磁流场的数学建模与应用

研究了铝电解槽复杂开域的媒质接触、结构化网格划分、磁场边界条件施加、场耦合等建模问题。运用标量电位法、标量磁位法和有限体积法在商业软件平台上开发了铝电解槽电一磁一流场的计算模块,并与工业电解槽上的测量数据对比验证其可靠性。在此基础上提出一种母线设计方法,获得较优的母线配置方案SG2。仿真结果表明：SG2水平电流小,磁场分布对称性好：熔体平行大面流动有助于氧化铝输运。磁场分析结果表明：立柱母线中的电流可大幅度抵消非均匀阴极母线电流对磁场分布的影响,决定最终磁场分布。     

大型预焙铝电解槽槽膛内形模拟计算

普通预焙槽电解过程会形成一定厚度的槽帮，它的形成对于铝电解生产的正常进行有着十分重要的作用。本文用有限元方法建立了一个200kA预焙槽的二维电热模型，通过循环迭代，模拟出了其槽膛内形。计算结果与现场测试结果比较表明，二者吻合较好。     

Hybrid supercapacitor based on polyaniline doped with lithium salt and activated carbon electrodes

Polyaniline(PANI) nanofiber was synthesized by interfacial polymerization utilizing the interface between HCl and CCl₄. The hybrid type supercapacitors (PLi/C) based on Li-doping polyaniline and activated carbon electrode were fabricated and compared with the redox type capacitors (PLi/PLi) based on two uniformly Li-doping polyaniline electrodes. The electrochemical performances of the two types of supercapacitors were characterized in non-aqueous electrolyte. PLi/C supercapacitors have a wider effective energy storage potential range and a higher upper potential. At the same time, the PLi/C supercapacitor exhibits a specific capacity of 120.93 F/g at initial discharge and retains 80% after 500 cycles. The ohmic internal resistance (R _ES) of PLi/C supercapacitor is 5.0 Ω, which is smaller than that of PLi/PLi capacitor (5.5 Ω). Moreover, it can be seen that Et₄NBF₄ organic solution is more suitable for using as organic electrolyte of PLi/C capacitor compared with organic solution containing LiPF₆. Foundation item: Project(2008AA03Z207) supported by the National High-Tech Research and Development Program of China     

Effect of doping Bi on oxygen evolution potential and corrosion behavior of Pb-based anode in zinc electrowinning

A new anodic material of ternary Pb-0.8%Ag-(0–5.0%)Bi alloy for zinc electrowinning was obtained by doping Bi. The anodic oxygen evolution potential, corrosion rate, surface products after polarization, and microstructures before and after polarization were studied and compared with those of Pb-0.8%Ag anode used in industry. The results show the anodic overpotential decreases with the increase of Bi content in the alloys. When the content of Bi is 1.0% (mass fraction), the anodic overpotential is 40–50 mV lower than that of Pb-0.8%Ag anode. While the corrosion rate decreases and then increases with the increase of Bi content. The Pb-0.8%Ag-0.1%Bi anode has the lowest corrosion rate (0.090 6 mg/(h·cm₂). Doping Bi influences the structure of the anodic layer, but does not change the phase. The Pb-0.8%Ag-1.0%Bi anode layer is of a more fine-grained structure compared with Pb-0.8%Ag anode. Foundation item: Project(2007SK2009) supported by the Science and Technology Research Project of Hunan Province, China     

铝电解控制中灰关联规则挖掘算法的应用

在事务拓扑空间的基础上,将灰色系统理论引入属性集的关联规则挖掘中,提出了一种新的适用于铝电解工业控制现场的灰关联度挖掘框架,并给出了基于该框架的灰关联规则挖掘算法,即Gray_CTL挖掘算法.将算法分解为两个小问题:1)计算关于时间属性的灰关联度,这是算法的核心;2)挖掘灰关联规则.以电解槽的热平衡数据挖掘为例,对某电解槽一个月的生产数据进行分析后,获得的灰关联规则说明该段时间内分子比、槽电压等因素对温度的影响程度较大.     

Physical modeling of gas induced bath flow in drained aluminum reduction cell

A room temperature physical model was used to study the bubble behavior and gas induced bath circulation in a drained aluminum reduction cell. By passing compressed argon through the penetrated Plexiglas box bottom plate immersed in water, gas evolution at the anode bottom surface was simulated. Bubble behavior and liquid flow field were studied and analysis was presented. Bath secondary recirculation was observed in the interpolar gap not the net rising flow as expected. Liquid driven by the bubbles forms small vortices along the interpolar gap with small mean and turbulent velocities and accordingly poor mass transfer. Secondary recirculation also exists between the slot and interpolar gap, part of the flow in the interpolar gap go to the slot with the bubbles and fluid at the bottom of the slot enters the interpolar gap directly without going to the center channel. The existence of the fluid secondary recirculation is very unfavorable to the alumina dissolution and dispersion. Increasing the anode tilt or gas flow rate, or decreasing the anode-cathode distance can make the secondary recirculation in the interpolar gap weak, however, will intensify the secondary recirculation between the slot and interpolar gap.