采用快速冷冻沉淀法制备出了非晶态纳米氢氧化镍。对制得材料样品进行了XRD,SEM,TEM,DSC和比表面积与孔径分析,将其制成MH-Ni电池正极材料进行充放电性能测试。结果表明:材料粉体为非品态,颗粒粒度为纳米级,类似球形。非晶纳米Ni(OH)2的热分解温度286.4℃低于常规球形Ni(OH)2的热分解温度333.8℃,同时具有较大得比表面积和孔径,分别为76.2089m^2·g^-1和37.7nm。与普通β-Ni(OH)2相比较,非晶态纳米氢氧化镍电极充电电压低,放电电压平台时间长,且高达1.258V,放电比容量为349.85mAh/g,具有较好的循环性能,20次循环后其容量衰减仅为1.28%。
The amorphous nano-Ni(OH)2 was synthesized by quick cryoprecipitation. The samples were characterized by XRD, SEM, TEM, DSC, BET surface area and electrochemical testing. The results show that the sample powder synthesized by this method is amorphous, and its shape is similar to spherical with the average particle size of 40 nm. The thermal decomposition temperature of amorphous nano-Ni(OH)2 (286.4 ℃) is lower than that offl-Ni(OH)2 (333.8 ℃), in addition, the nano-Ni(OH)2 has larger specific surface area (76.2089 m^2·g^-1) and pore size (37.7 nm). Compared with the microsized spherical fl-Ni(OH)2, the amorphous nano-Ni(OH)2 exhibits excellent electrochemical performance, such as lower charge voltage, higher discharge platform and better charge-discharge capacity. Also, a maximum capacity of 349.85 mAh·g^-1 and the highest discharge voltage of 1.258 V were obtained for this electrode. It also exhibits better cycle performance, and the capacity fading rate is only 1.28% after 20 cycles.