炭基双电层电容器的工艺研究及优化

以化学和物理性质稳定、导电性好的活性炭纤维（ACF）为电极材料，KOH溶液为电解液，研制炭基双电层电容器。研究了电解液浸渍电极时体系的真空度、KOH质量分数、电极片组成及厚度对双电层电容器性能的影响，并通过正交实验优化制备双电层电容器的工艺条件。结果显示，高真空度、高质量分数电解液有助于提高电容量。以质量分数40％KOH溶液为电解液，电极组成为ACF：石墨：聚四氟乙烯=1．6：0．4：1，单个电极片质量为0．10g的最佳工艺条件，得到的双电层电容器中活性炭纤维的比电容可达到152．81F／g。     

乙醛电合成乙二醛的研究

采用电化学方法用乙醛合成了乙二醛。以DSA(dimensionally stable anodes)电极作阳极,铅电极做阴极,阳离子交换膜作电解液隔离膜,亚硝酸钠和氯化镁溶于乙醛水溶液配制的混合溶液作阳极电解液,盐酸溶液作阴极电解液。在电解电压为2.5 V,电解时间为3 h,超声波频率为40 kHz、功率为60 W,电解温度为25℃的条件下电解乙醛生成乙二醛,最大产率为14.4%。     

高度有序多孔阳极氧化铝制备工艺的研究

影响多孔阳极氧化铝(porous anodica lumina,PAA)形貌及结构等的因素有很多,如抛光铝片的表面粗糙度、电解液温度、氧化电压、氧化时间、搅拌速率等。本文采用二次阳极氧化法,以草酸为电解液,研究了高度有序AAO模板制备过程的主要工艺条件,并采用扫描电子显微镜对模板的形貌进行表征。结果表明,在电解液温度为12℃,氧化电压为40V能够得到高度有序的、孔径为80nm左右的多孔阳极氧化铝膜。     

活性炭纤维去除水中直接深蓝L-3RB及其再生研究

用红外及可见分子吸收光谱法研究了活性炭纤维(ACF)对直接深蓝L-3BR(DDB,C．I．Direct Blue 71)的吸收行为。用电化学法研究了DDB饱和吸附后ACF再生的可能性。发现ACF最佳吸附条件为pH=5;以2％NaCl％水溶液为支持电解液,用铜棒和石墨棒分别作阴极和阳极,阴极区ACF再生率达到95％,初步探讨了ACF对DDB的吸附和脱附DDB的机理。     

沙柳活性炭纤维对铜离子的吸附及动力学分析

以沙柳活性炭纤维(ACF)吸附水体中的Cu~(2+)离子,讨论吸附时间、ACF投加量、pH、温度及溶液浓度对铜离子去除率的影响,并研究了沙柳ACF对铜离子的吸附动力学。结果表明,在pH为4.1,ACF投加量0.4 g,温度45℃,铜离子溶液浓度100 mg/L,吸附时间90 min的条件下,ACF对铜离子去除率达70%,且pH是影响铜离子去除率的第一因素,准二级动力学模型可以更理想地描述沙柳ACF对铜离子的吸附过程。     

沙柳活性炭纤维对铜离子的吸附及动力学分析

以沙柳活性炭纤维(ACF)吸附水体中的Cu⁽²⁺⁾离子,讨论吸附时间、ACF投加量、pH、温度及溶液浓度对铜离子去除率的影响,并研究了沙柳ACF对铜离子的吸附动力学。结果表明,在pH为4.1,ACF投加量0.4 g,温度45℃,铜离子溶液浓度100 mg/L,吸附时间90 min的条件下,ACF对铜离子去除率达70%,且pH是影响铜离子去除率的第一因素,准二级动力学模型可以更理想地描述沙柳ACF对铜离子的吸附过程。     

超级电容器有机低温电解液的制备及电化学性能研究

超级电容器低温性能的好坏与其电极材料及电解液密切相关,通过电化学测试研究了以活性炭和石墨烯为电极材料,1mol·L-1不同体积含量丙酸甲酯(MP)的SBP-BF4/(PC+DMC+MP)体系为电解液的超级电容不同温度时的电化学性能,分析发现,MP有助于提升有机电解液的低温性能,MP溶剂体积分数为33％的活性炭超级电容可...     

Zn-PTFE复合电极电合成2,3-二甲基-2,3-丁二醇

研究以自制的Zn -PTFE复合电极为阴极 ,电合成 2 ,3 二甲基 2 ,3 丁二醇 (频那醇 )。探讨了复合电极中PTFE质量分数、阴极电流密度、电解液温度、电解电量对频那醇产率的影响。实验结果表明 :以Zn -PTFE [w(PTFE) =6 .2 5 % ]复合电极为阴极 ,当阴极电流密度为 2 .5A/dm2 ,电解液温度为 15℃ ,电解至理论电量的 140 %时 ,电合成频那醇的产率可达 5 3.6 % ,产品的红外谱图与标准谱图相符。     

钛基TiO_2纳米管光电催化降解甲基橙

采用阳极氧化法制备了TiO2纳米管,并进行扫描电镜分析。以TiO2纳米管为工作电极,石墨作对电极,对甲基橙溶液进行光电催化降解研究,考察了阳极氧化电压、时间、热处理温度、电解液组成、外加偏压的影响。结果表明,阳极氧化电压为20 V,氧化时间20 min,热处理温度500℃,V(H3PO4)∶V(NH4F)=1∶1,外加偏压为0.6 V时,甲基橙(5 mg/L)经TiO2纳米管光电催化30 min,脱色率达到96.3%。     

钛基TiO_2纳米管光电催化降解甲基橙

采用阳极氧化法制备了TiO2纳米管,并进行扫描电镜分析。以TiO2纳米管为工作电极,石墨作对电极,对甲基橙溶液进行光电催化降解研究,考察了阳极氧化电压、时间、热处理温度、电解液组成、外加偏压的影响。结果表明,阳极氧化电压为20 V,氧化时间20 min,热处理温度500℃,V(H3PO4)∶V(NH4F)=1∶1,外加偏压为0.6 V时,甲基橙(5 mg/L)经TiO2纳米管光电催化30 min,脱色率达到96.3%。     

The Influence of Ni Content on the Stability of Copper—Nickel Alloys in Alkaline Sulphate Solutions

The electrochemical behaviour of copper–nickel alloys with different Ni content (5–65%) in sulphate solutions of pH 12 was investigated. The effects of temperature, immersion time, and concentration of sulphate ions were also studied. Different electrochemical methods such as open-circuit potential measurements, polarization techniques and electrochemical impedance spectroscopy (EIS) were used. Potentiodynamic measurements reveal that the increase in nickel content increases the corrosion rate of the alloy in sulphate solution linearly. Nevertheless, an increase in the nickel content along with increase in immersion time improves the stability of the Cu–Ni alloys due to the formation of a stable passive film. An equivalent circuit model for the electrode/electrolyte interface under different conditions was proposed. The experimental impedance data were fitted to theoretical data according to the proposed model. The relevance of the model to the corrosion/passivation phenomena occurring at the electrode/solution interface was discussed.     

Bioelectrocatalytic Carbon Ceramic Gas Electrode for Reduction of Dioxygen and Its Application in a Zinc–Dioxygen Cell

An enzyme‐modified carbon ceramic electrode was constructed and studied that is capable to reduce dioxygen supplied from the gas phase. The permeation of the electrode material and its hydrophobic silicate component was studied by scanning electrochemical microscopy. The mass‐transfer coefficient of dioxygen in methyltrimethoxysilane‐based silicate was estimated to be 6.44 × 10^–5 cm² s^–1. After modification of the electrode with bilirubin oxidase and immersion in deareated aqueous electrolyte, the dioxygen bioelectrocatalytic reduction is observed with onset potential at 0.45 V. The constructed electrode was successfully applied as cathode in a zinc–dioxygen cell.     

Surface layer formation on Sn anode: ATR FTIR spectroscopic characterization

Surface layer formed on Sn thin film electrode in 1 M LiPF₆/EC:DMC electrolyte was characterized using ex situ FTIR spectroscopy with the attenuated total reflection technique. IR spectral analyses showed that the immersion of Sn film in the electrolyte resulted in a chemical interfacial reaction leading to the passivation of Sn surface with primarily PF-containing inorganic surface species and small amount of organics. When constant current cycling was conducted with lithium cells with Sn film electrode at 0.1-1.0 V vs. Li/Li⁺, the interfacial reaction between Sn and electrolyte appeared significantly intensified that the features of PF-containing species became enhanced and new IR features of organic species (e.g. alkyl carbonate/carboxylate metal salts and ester functionalities) were observed. The surface layer continued to form with cycling, partly due to non-effective surface passivation as well as particle pulverization accompanied by enlargement of active surface area. Comparative IR spectral analyses indicated that the interfacial reaction between Sn and PF₆⁻ anion played a leading role in forming the surface layer, which is different from lithiated graphite that had mainly organic surface species. The data contribute to a better understanding of the interfacial processes occurring on Sn-based anode materials in lithium-ion batteries.     

The Limiting Diffusion Current of an Electrode in a Chaotically Stirred Electrolyte

The diffusion current was studied as a function of the electrode size and the hydrodynamics characteristics turbulent flow of the electrolyte. Five mechanisms of mass transfer to the electrode surface were considered. The conditions for uniform accessibility of the electrode surface for the diffusing electrolyte were determined.     

Electrochemical impedance spectroscopy of the alkaline manganese dioxide electrode

Two-probe electrochemical impedance spectroscopy measurements were carried out on the electrolytic manganese dioxide electrode in concentrated KOH electrolytes under a variety of experimental conditions. These included varying the electrode thickness and compaction pressure, electrolyte content and concentration, degree of manganese dioxide reduction and the presence of TiO₂ (anatase) as an additive. The overall electrode impedance was found to decrease when thin electrodes, prepared under high compaction pressures, with an excess of electrolyte, were used. The impedance of the EMD/electrolyte interface was also minimized when 5.0 M KOH was used as the electrolyte. This correlates with a maximum in electrolyte conductivity. The electrode impedance also increased as the degree of EMD reduction was increased, as was expected. Under these experimental conditions the electrode impedance increased in the presence of TiO₂ (anatase), which has negative implications for its commercial use. This conclusion was reached despite the differences in experimental conditions between this work and in commercial applications. An equivalent circuit was also derived and used as an aid in interpreting the impedance data.     

A calibration technique for an Ag/AgCl reference electrode utilizing the relationship between the electrical conductivity and the KCl concentration of the internal electrolyte

For ensuring the long-term performance of an Ag/AgCl reference electrode, a calibration technique was developed by using the linear relationship between the electrical conductivity and the KCl concentration of an internal electrolyte. It was observed that the electrical conductivities increased with an increase of the KCl concentration of the internal electrolyte, and the potentials of the Ag/AgCl electrode shifted anodically with a decrease of the KCl concentration. For simulating a long-term exposure of the electrode, we designed a reference electrode with a tiny perforation to accelerate the diffusion of the internal electrolyte. During the acceleration tests, the potentials of the Ag/AgCl electrode were shifted by almost the same amount as the potentials calculated from the change of the electrical conductivity of the internal electrolyte. Consequently, this technique was confirmed to be applicable for the calibration of an Ag/AgCl electrode, especially when exposed to non-electrolytic aqueous solutions.     

Effect of Zn and Pb as alloying elements on the electrochemical behavior of brass in NaCl solutions

The electrochemical behavior of brasses with various Zn content (5.5–38 mass%) and brass (Cu–38Zn) with different Pb contents (1–3.4 mass%) in 0.6 M NaCl was investigated. The effects of temperature, immersion time, and concentration of chloride ions on the behavior of the different alloys were studied. The pitting corrosion behavior of Cu–Zn alloys and leaded–brass alloys in 0.6 M NaCl solution was also investigated. Open-circuit potential measurements (OCP), polarization techniques and electrochemical impedance spectroscopy (EIS) were used. The results show that the increase in the Zn content increases the corrosion rate of the brass alloys in chloride solutions, while the increase of Pb content in Cu–38Zn–Pb decreases the corrosion rate of the alloy. Long immersion time of the alloys in the aqueous electrolyte improves their stability due to the formation of passive film on the alloy surface. The breakdown potential is shifted to more negative direction with increasing the Zn content, whereas it shifts towards positive values with increasing Pb content. Equivalent circuit model for the electrode/electrolyte interface under different conditions was proposed to illustrate the electrochemical processes taking place at the interface. The electrochemical behavior of the different alloys was discussed in view of the fitting results.     

全固态锂离子电池技术进展及现状

锂离子电池电解质多为有机液体,易燃易爆、安全性差。用固态电解质制备的全固态锂离子电池,具有电化学窗口宽、能量密度大和安全性高等优点,是电动汽车和规模化储能应用的理想化学电源。本工作主要介绍了全固态电解质的电解质材料及电极/电解质界面调控与机理问题,为改善固/固界面相容性及降低界面阻抗方面提供解决方案。阐述了目前主流的正负极材料、全固态锂离子电池的设计及目前的专利申请状况,简要讨论了全固态锂离子电池面临的主要问题,并从产业应用角度展望了其应用现状和未来发展趋势,为从业者全面了解全固态电池的发展提供有利依据。     

锂离子电池电极材料SEI膜的研究概况*

综述了锂离子电池电极材料表面的“固体电解质界面膜”（SEI 膜） 的成膜机理及研究概况,并分析了电解液、温度和电流密度对SEI膜形成过程的影响;在此基础上,对SEI膜的改性（主要包括电极材料的改性和添加电解液添加剂）进行了分析,认为SEI膜的研究将对电极材料和电解液添加剂的改进研究产生重要影响。     

Coating manganese oxide onto graphite electrodes by immersion for electrochemical capacitors

In this study, manganese oxide was coated on a graphite electrode by immersion. Durations for immersion were varied to control the amount of manganese oxide coated onto the electrode surface. Maximum capacitance of 556 mF cm⁻² was obtained in 0.5 M LiCl and with better/superior conditions (immersion time = 80 min and potential scan rate = 10 mV s⁻¹). In addition, cyclic voltammograms of the prepared electrode at different potential scan rates exhibited the approximately rectangular and symmetric current-potential characteristics of a capacitor. Furthermore, the chronopotentiometry (CP) charge-discharge curves of the electrode prepared at 80 min of immersion time with a constant current of 1 mA were symmetric and similar isosceles triangles, which demonstrate its high electrochemical reversibility and good stability. Finally, under scanning electron microscope (SEM), the surface of the electrode prepared at 80 min of immersion time and after 1500 cycles of potential cycling revealed that numerously three-dimensional network of macropores appeared on large spherical grains.