Electrochemical properties of silicon-doped MlNi_5 rare earth hydrogen storage alloys

5 Electrochemical performances of 15 old silicon-based thief rare earth hydrogen storage alloys Guo Shengwu, Zhang Yong, Zhang Zhongping, Liu Yongning Xi'an Jiaoren University of Science and Technology of China, Xi'an 710049, Fast fire current discharge capacitor, 1 set. Ray finds 哳 and 扫. Mirror observation called the system. From the non-hydrogen storage phase 127 phase increase, 15 base hydrogen storage alloy is a kind of ideal battery anode material, it has the characteristics of human capacity charge and discharge and easy to activate, but the material in the charge-discharge cycle capacity attenuation As soon as 100 cycles, the capacity loss is less than 50, which brings great difficulties to the commercialization of the product. In recent years, people have been studying and exploring improvements to this material. At present, the commonly used method is to use mixed rare earth instead of pure yttrium, and to replace it with yttrium, and other elements such as 15 alloy, so that the cycle life of the electrode is greatly improved 2. But when the alloy contains 0.75, its mass fraction is only 10, However, the price occupies 5055 of the alloy price. Therefore, choosing the appropriate element to replace the high price is a key factor in the electrode material's ability to adapt to market demand. In general, the multi-prime mixing effect was used instead, and the content was only reduced to 0.75, so the cost reduction was not very satisfactory and a low-cost high performance such as 3.5.1.75., 941 view was prepared. 55 gamma 1 generation of lanthanum rich rare earth metal mixture, 1 = 0.0.0.2.0.3.0.4 hydride electrode material. And studied the electrochemical properties of the alloy and the microstructure of its performance 1 experimental method to prepare metal, placed in a water-cooled copper crucible, using argon arc melting protection prepared. For example, the mass fraction was broken and sieved through a 150-mesh sieve, electrochemical testing, and ray diffraction analysis were performed, and the remaining alloy ingots were analyzed for microstructure.

The sifted alloy powder 4 nickel powder is blended in a mass ratio and an appropriate amount of the mass fraction of 9 is fully mixed to form a paste, and is evenly filled into a foamed nickel substrate of 1.5, 2. At 353, the electrode sheet is pressed down. 80 bake, soak in the solution of 6,1, and 24. make a negative electrode to identify the old 2 as 1 pole, reference Tunji use beer. Hungry open electrode system. On the battery and electrode performance test bench at room temperature charge and discharge experiments.

The constant current method is used to measure the discharge capacity of the electrode, and the phase shift structure of the electrode is defined as the charge current density of the charge electrode (60). Analysis using 52700 Scanning Electron Microscopy = 2 Experimental Results and Discussion 2.1 Microstructure and Phase Structure of the Alloy Assay Metallographic structure of the as-cast alloy It can be seen that the alloy is a two-phase structure, and the apparent alloy is in the cooling process. 199 Less 1027; Revised Date 199927 Fund Project The Xi'an Jiaotong University Science Research Fund project has segregated components, and with the increase of 5 content, the black tissue composition has increased. The degree of segregation worsened.

An energy spectrum analysis of the two species of hunger metabolites was carried out by scanning electron microscope 1 and the results showed that the composition of the black tissue composition was 3 states 7 and the composition of the white tissue composition was 35. X-ray diffraction analysis also confirmed that the gold-containing structure was divided by 1; Type 5 1. Phase 3 is also precipitated, and 10.2 alloy. 3 to do 7 phase peak ratio. = 0.1 combined island, this shows. The 327 phase content of the 0.2 alloy is more than that of the 0.1 = alloy. The benzoxygen ability of the 7 phase of the 32 states is significantly different from that of the main phase. Therefore, its presence has a significant effect on the electrochemical capacity of the Beish hydrogen alloy. .

2.2 Electrochemical Performance Test The electrochemical activation rate of alloy electrodes made with different 31 contents was measured as the number of chambers. From the chamber, it can be seen that with the increase of the amount of 3, the activation rate of the alloy increases, and the discharge capacity of the alloy decreases. The 3.53551412 river has the smallest discharge capacity of 1.55. The discharge capacity of all alloys after 13 cycles had basically reached the maximum value, ie the number of activations was only 13. The main reason was that the content of 81 in the gold was increased. Good result; 7 more structural phase. The high electrocatalytic activity of Yamagata in 127 has a high electrocatalytic activity. Therefore, the electrode activation speed is increased. However, at the same time, 3 Hao 7 phase and hydrogen tend to form a more stable 3 black tissue composition; the white tissue composition has a cyclically determined metal hydride. This reduces the content of active hydrogen in the alloy, which leads to a decline in the capacity of the gold discharge capacitor. Metallographic analysis also confirmed that the increase in content of 1217 with increasing the content of 31 gold in the gold chamber 1. The study was significantly smaller, for the multicomponent hydrogen storage electrode alloy. The factors that affect its electrochemical capacity are the electronegativity of the yttrium element, and the elements of the negatively charged ones are replaced with each other, and the high-capacitance of the electrode is maintained when the dyad is reduced. The experimental results are small 5. The content is. 1.1 hours. The maximum value of the discharge capacity of the alloy 6 is 305 and the number of 81 is 0 0.2, and 273 is 131.4 inches. Replacing part of the meaning, you can catch up with the high performance price ratio.

Table performance, from the content of 3 can be less than 0.2, the alloy discharge voltage platform is relatively stable. Then the flatness of the discharge voltage is gradually reduced. The main reason is that the hydrogen discharge alloy electrode discharge voltage platform performance depends to a large extent on the homogeneity of the hydrogen storage alloy. The more uniform the hydrogen storage alloy structure, the more stable the discharge voltage platform is, the Yicon 3 content is less than 0.2. The uniformity of the organization is better, so the noble metal content in the alloy should not be greater than 0.55.22. The 55 discharge capacity test under different discharge regimes 7 shows significant results. Substituting a small amount for 0 can not only improve the ability of small current discharge. But also can increase the discharge capacity of the large current. PCT 3., 0.65 to 10.2. The discharge capacity of the 55 discharge system with 218〃1 is still 287131. This is mainly due to the amount of 127 phases in the alloy. Paired gold has a higher electrocatalytic activity.

The discharge current density mAg13 conclusion catch 3.5, 0.75 in 10.2 as. 55 has excellent electro-activation performance, and as 1 increases, the electrical activation performance increases.

Time. Electrochemical 7 capacity of the alloy is set up. Achieve 3051 to 1.81=0.2. The electrochemical voltage capacity of gold-plated gold alloys and the high voltage-to-metal ratio of the Alpha-based voltage plateau at 1 = 0 is a new type of electrode material worthy of promotion: Chen Weixiang, Tang Zhiyuan, Guo Hetong, et al. Non-stoichiometric mixed rare earth nickel is studied in hydrogen alloys. Chinese Journal of Metals, 1998, 342184188.

Zhao Shuang. Lin Qin Chen Ning, et al. 15. Calculation and Prediction of Hydrogen Storage Properties of Alloy Hydrides. Chinese Journal of Metals, 1999, 3516669.

Guan Guan, Guan Guan, Guan Zheng, Guan Wei, Hong Hong, Shui Wei, Zhao Guiwen (Department of Chemistry, University of Science and Technology of China, Hefei 230026, China), and studied their ultraviolet spectra but similar to seven and zero. Infrared spectroscopy, 10. The complex of rare earth chlorophyll 3 and the 8 spectrum is Wang Wang 3, pay band split. , Hysteresis, other features with disappeared. The spectrum of these complexes is very similar to that of chlorophyll-containing light. However, the spectral properties of magnesium chlorophyll 1 are quite different. Proved that ten, rape, can be assigned to de-sulphur is Meiji sandwich complex =