| A novel solution reaction method based on hydrothermal stripping has been developed, and theβ-Ni(OH)2 nanocrystallites as MH/Ni batter cathode material were successfully synthesized by stripping nickel-loaded organic phase. The measurement results of XRD, IR, TEM and SEM show that the samples prepared by this method are the regular nanoparticles with single phase and uniform distribution. The electrochemical measurements indicate that the samples have excellent electrochemical performance, such as the discharge capacity and discharge potential plateau, cycle stability and high-rate discharge ability.In this paper, the method and some factors influencingβ-Ni(OH)2 synthesized by stripping nickel from nickel-loaded naphthenic acid-isooctanol system and P204-kerosene system were mainly investigated.Some factors, such as the pH value, the stripping temperature and time and so on, which influenced on microstructure, constitute, morphology and practical size, were investigated for naphthenic acid-isooctanol system. The results indicated that the most significant factors are the pH value and stripping temperature. When contacted with water (pH=7) at 140240°C for 2.0 h, the nickel-loaded naphthenic acid was stripped to recover nickel as high-quality spherical nano-β-Ni(OH)2.Some factors, such as the concentration of NaOH,the stripping temperature,the kind and amount of surfactant, the ratio of organic and water phase and so on, which influenced on microstructure, constitute, morphology and practical size, were investigated for P204-kerosene system. The results indicate that the primary factor is the concentration of NaOH, the secondary factors are temperature, the amount of surfactant and time respectively. When contacted with the water phase of 1.0 mol·L-1 NaOH at 80°C for 3.0 h, the nickel-loaded P204 was stripped to recover nickel as smaller particle size spherical nano-β-Ni(OH)2.As a contrast,β-Ni(OH)2 was also synthesized by traditional liquid phase methods, such as deposition conversion and complexation deposition. Compared with other method, the hydrothermal stripping is a facile, fast, energy, low consumption of drugs and green synthesis (organic and water phases could be recycled) method, and more suitable for industrial production. Compared with the performances shows that theβ-Ni(OH)2 prepared by hydrothermal stripping is unique microstructure, regular morphology, smaller practical size and uniform distribution, higher electrochemical activity.The electrochemical performance shows that the charge and discharge of the samples prepared by hydrothermal stripping are better than by other methods, and the performance of samples synthesized by stripping P204-kerosene organic system is slightly better than naphthenic acid-isooctanol system. In this paper, the synthesis of nano-β-Ni(OH)2 significantly improved the electrochemical properties, not only can reduce the polarization, increase charge and discharge current density, but also raise the discharge capacity and extend cycle life. |
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