18 research outputs found
Some Effects of Co on the Electrochromic Properties of NiO xH y Film
本文利用阴极化电沉积法在抛光镍板及ITO玻璃表面制备了含Co量为16.2%的NiOxHy薄膜,薄膜厚度分别为42nm、21nm,采用透射光谱以及线性电位扫描、交流阻抗和阳极稳态极化曲线等测试技术,考察了Co对NiOxHy薄膜电致变色性能的影响,光谱测试范围为300~2500nm.结果发现:Co能降低薄膜着色态在可见光区及部分近红外区的透过率,通过电压调节不仅可以调光而且可望能够控温;同时Co还能降低NiOxHy薄膜电致变色电位,升高薄膜氧化着色过程中的氧析出过电位,对薄膜的电致变色性能有改进作用,但降低了着色过程中质子的扩散系数.Some effects of Co addition upon the electrochromic characteristics of a nic_kel hydroxide film were studied. The films were electrodeposited on both polished Ni plate and conductive ITO glass. The electrochemical behaviors were investigated using the film on Ni plate by linear potential sweep, a.c. impedance, and anodic polarization curves for OER(oxygen evolution reaction). It was found that Co can lower the working voltage and raise the oxygen overpotential, but has little effect on the reaction kinetics. It was also found that the Co can improve the optical properties of the electrochromic film.作者联系地址:南开大学新能源材料化学研究所Author's Address: Inst. of New Energy Material Chem. Nankai Univ., Tianjin 30007
用色谱-质谱和质量色谱研究苯甲酸钐热分解反应
为合成某些芳香族有机化合物提供一种新途径,用色谱-质谱联用技术和质量色谱法研究了苯甲酸钐的热分解反应产物。其热分解产物溶入丙酮后有大量9,10-蒽醌析出,其丙酮溶液中还含有1,2-二苯甲酰基苯(256%)、苯甲酸(187%)、二苯酮(144%)、9-芴酮(82%)、9-苯基芴(49%)、联苯(36%)、二苯甲烷(23%)、3-甲酰苯基联苯(21%)、二苯基乙二酮(19%)、4-甲酰苯基联苯(18%)、芴(17%)、m-二苯甲酰基苯(11%)和p-二苯甲酰基苯(02%)等55种化
Electrochemical Performance of C-LiFePO_4 by Polyaniline Doping
应用固相反应法在惰性气氛下合成橄榄石型LiFePO4,然后制成聚苯胺掺杂C-LiFePO4复合正极材料.XRD,交流阻抗及电化学方法等测试表明,聚苯胺掺杂对LiFePO4电化学性能有一定的改善.当放电倍率为0.1C时,掺杂10%聚苯胺的(C-LiFePO4)0.9(PANI)0.1样品的放电容量达到164 mAh.g-1,且循环稳定性良好.在0.5C和1C的放电倍率下,也可以分别达到121.6 mAh.g-1和110.1 mAh.g-1的放电比容量.The olivine LiFePO4 cathode materials were synthesized using the solid state method in an inert atmosphere by doping polyaniline into the C-LiFePO4.It was found that the electrochemical performance of polyaniline-doped C-LiFePO4 slightly improved.At a low discharging rate(0.1C), the capability of(C-LiFePO4)0.9(PANI)0.1 reached 164 mAh·g-1.When the charge-discharge rate is increased to 0.5C and 1.0C,the showed capacities of 121.6 mAh·g-1 and 110.1 mAh·g-1 were obtained,respectively.作者联系地址:南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所 天津300071,天津300071,天津300071Author's Address: Institude of New Energy Material Chemisity,Nankai University,Tianjin 300071,Chin
The Effect of Co on the Proton Diffusion Coefficient for the Ni(OH)2 Electrodes
本文采用恒电位阶跃、循环伏安及恒电流放电法,考察含Co量0%~53%的Ni(oH)_2电极充放电过程中质子的扩散系数:充电过程该值为10-9~10-10cm2/s,放电过程则为10(-11)cm2/s.数据处理时对文献中有关公式进行了修正.The diffusion coefficients of protons moving in the Ni(OH)2 electrodes have being investigated by constant current,cyclic voltammetry and potential step technineques.The electrodes were prepared by cathodic deposition and their active material contained 0~53% cobalt.It was found that the diffusion coefficients are about 10(-9)~10(-10) cm2/s during charging and about 10(-11) cm2/s during discharging.Moreover the value increases with the increacing content of Co in the electrodes.During the calculation,the relevant fomulars were modified especially the wrong fomular for constant current methode.作者联系地址:南开大学新能源材料化学研究所Author's Address: Institute of New Energy Material Chemistry,Nankai University,Tianjin 30007
Oxygen Evolution Behavour on Ni Electrode in KOH Solution
用恒电流法测试在22~70℃之间电解30wt.%KOH水溶液时Ni阳极的稳态极化曲线以及该过程的交换电流密度i0,Tafel斜率b,传递系数β和不同电流密度下的析氧过电位随电解温度的变化关系结果发现:40℃是各参量随温度变化的一个突出变点,40℃以下,高过电位区的Tafel斜率达120mV以上,低过电位区的反应活化能Ea为79.88kJ/mol,而40℃以上时,上述两参数分别为60~70mV和55.32kJ/mol.另外两温度区间的(η/T)1及其随lgi的变化也有显著差别The steady_state polarization curves of oxygen evolution were measured at temperatures between 22~70 ℃ on Ni electrode in 30 wt.% KOH solution by galvanostat methode. The exchange current densities, Tafel slopes and transfer coefficients were studied. It was found that 40 ℃ is a special temperature, near which the kinetic parameters change abrupdy. The Tafel slopes for oxygen evolution reactions at higher overpotentials change from more than 120 mV to about 70 mV when the temperature raises to 40~70 ℃ from 22~35 ℃. Simultaneously, the heat of activation is changes from 79.88 kJ/mol to 55.32 kJ/mol. Moreover, the -(η/Τ) i and how it changes with lg i are quite different in the two temperature ranges: The slope of -(η/Τ) i vs. lg i is 4.63 at the lower temperatures, while at the higher temperatures it is only -0.455.作者联系地址:南开大学新能源材料化学研究所Author's Address: Inst. of New Energy Material Chem. Nankai Univ. Tianjin 30007
Calcined Temperatures Influence on Synthesis and Electrochemistry Charactarization of Li[Ni_(0.475)Mn_(0.475)Co_(0.05)]O_(2) for Li-ion Batteries
应用高温固相合成法制备L i[N i0.475Mn0.475Co0.05]O2.XRD,SEM,循环伏安及充放电容量测试表明,在800℃下煅烧合成的样品具有较高的嵌锂容量和良好的循环稳定性,如在20 mA/g和2.3~4.6 V的电压范围内,其首次放电比容量为178.8 mAh/g,循环30周后放电比容量仍能达到150.2 mAh/g,容量损失16.0%.Layered Li[Ni_(0.475)Mn_(0.475)Co_(0.05)]O_(2) materials have been prepared by a solid-state pyrolysis method.Experiments of XRD,SEM,cyclic voltammetry and charge/discharge cycling were carried out.It can be learned that when calclined at 800 ℃,the sample showed the highest first discharge capacity of 178.8 mAh·g~(-1) at a current density of 20 mA/g in the voltage range 2.3~4.6 V.作者联系地址:南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所 天津300071,天津300071,天津300071,天津300071Author's Address: *,WANG Yong-meiInstitute of New Energy Material Chemistry,Nankai University,Tianjin 300071,Chin
Studies of Electrochemical Characteristics of Pasted Nickel Hydroxide Electrode with Surface Deposited Cobalt
研究了在碱性可充电电池正极活性物质—球型氢氧化镍粒子表面化学镀钴后氢氧化镍电极的性能.通过比较充放电曲线和循环伏安试验结果,讨论了电极的放电容量、活性物质利用率和Ni(OH)2/NiOOH氧化还原可逆性.实验还发现镀钴后的氢氧化镍电极有更好的充放电性能和优良的电极特性.测定了化学镀钴前后氢氧化镍电极的交流阻抗,表明镀钴后氢氧化镍的基体之间的有较低接触电阻.此外,本文还对钴镀层改进氢氧化镍性能的机理进行了讨论.The surface of the spherical nickel hydroxide particles used as an active material in pasted nickel electrodes is surface_deposited with cobalt. This paper investigated the effects of the amount of cobalt deposit on the characteristics of nickel hydroxide electrode. The performances of the electrode, such as discharge capacity, utilization of active material and reversibility of Ni(OH) 2/NiOOH redox reaction, were studied by comparing the charging/discharging curves and cyclic voltammograms. The mechanism of action of cobalt deposits has been described in terms of the electrochemical impedance spectroscopy of nickel hydroxide electrode.作者联系地址:南开大学新能源材料化学研究所Author's Address: Institute of New Enery Material Chemistry, Nankai University, Tianjin 30007
Behavior of Copper in Hydrogen Storage Alloy Microencapsulated by Copper
在密封的电池体系中(即贫液状态),包铜储氢合金电极具有较好的抗氧化能力;而在强碱性溶液中(即富液状态),铜在电极工作的电位范围内(-1.1~-0.4V)具有一定的稳定性,但当扩展扫描范围(-1.1~-0.2V),将出现铜的氧化还原反应.随着充放电循环的进行,铜被氧化成Cu2O,进而形成CuO2-2进入电解质(KOH)溶液中,充电时又以Cu的形式于电极表面析出.针对这一现象,本文利用电位阶跃实验研究了CuO2-2离子在镍电极上的电沉积过程,结果表明该过程遵循二维瞬时成核机理Negative electrode made from Cu microencapsulated hydrogen storage alloy was studied by using cyclic voltammetry method. The results showed that copper as a coating material was of a certain stability in 5 mol/L KOH solution within the range of charge and discharge voltage. But when expanding the sweep voltage, the CV curve showed a pair of distinct oxidation reduction current peaks of Cu 2O formation at E =-0.3 V and Cu 2O reduction at E =-0.6 V. With charging discharging cycles, copper is liable to be oxidized to Cu 2O and further oxidized into CuO 2- 2. When charged again, CuO 2- 2 anion is reduced and Cu is electrodeposited on the sufrace of electroce. In respond to this phenomenon, the electrodeposition process of CuO 2- 2 on the smooth Ni electrode was studied by constant potential step technique. The results showed that the deposition process of copper followed the two dimension instantaneous mechanism.作者联系地址:南开大学新能源材料化学研究所Author's Address: Inst. of New Energy Material Chem., Nankai Univ., Tianjin 30007
