Tw-80对纳米Ni(OH)2振实密度及其复合电极放电性能的影响

Effect of Tw-80 on Tap Density and Discharge Capability of Combination Electrode of Nano-Scale Ni(OH)2

摘要:

以吐温-80（Tw-80）即C64H124O26-80作分散剂，用超声波沉淀法制备出针形和准球形混合的纳米β-Ni(OH)2，将制备的纳米粉体以8%（质量分数，下同）比例掺入到微米级球镍中制成复合镍正极，LaNi5合金制成电池负极，研究了不同Tw-80比对纳米粉体振实密度及其复合镍正极放电性能的影响。结果表明：振实密度和放电容量均随Tw-80用量增加先增大后减小；复合镍电极的放电平台比纯球镍电极高；Tw-80用量为2%制备的纳米粉体，以8%比例与球镍混合时，其复合镍电极的放电容量最大，达到256.7 mA

Abstract:

The β-Ni(OH)2 nano-scale powder with needle-like and quasi-spheroshape was prepared by supersonic-assistant precipitation method using Tween-80 (C64H124O26-80) as dispersant. The prepared powder was added into micron-scale spheroshape nickel hydroxide at a ratio of 8% to get a combination electrode. Using the combination electrode as anode and LaNi5 alloy as cathode, the effect of Tw-80 dosage on the tap density of β-Ni(OH)2 and the discharge capability of the combination Ni electrode was studied. The result showed that both the tap density and the discharge capability increased at first, then decreased as the increase of dosage of Tw-80. The combination electrodes have a higher discharge voltage than the pure spheroshape Ni(OH)2. The maximum discharged capability with 256.75 mAh/g was obtained when the nanopowder with 2% dosage of Tw-80 was mixed with pure spheroshape Ni(OH)2 at a ratio of 8%. The capacity was 11.3% higher than that of the pure spheroshape Ni(OH)2 (230.7 mAh/g). Besides, the cycle life of the mixed electrode was also increased.