文章基本信息

标题：Investigation of Ni-Al hydroxide with silver addition as an active substance of alkaline batteries
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作者：Valerii Kotok ; Vadym Kovalenko ; Sergey Vlasov 等
期刊名称：Eastern-European Journal of Enterprise Technologies
印刷版ISSN：1729-3774
电子版ISSN：1729-4061
出版年度：2018
卷号：3
期号：6
页码：6-11
DOI：10.15587/1729-4061.2018.133465
语种：English
出版社：PC Technology Center
摘要：Layered double hydroxides with different ratios of nickel and aluminum in the presence of Ag + ions and without silver have been synthesized: Ni: Al – 80 %: 20 %, Ni: Al: Ag – 80 %: 15 %: 5 % and 75 %: 15 %: 5 %. The obtained nickel hydroxide powders have a structure similar to α-Ni(OH)2 with a large number of crystal lattice defects. As a result of galvanostatic charge-discharge cycling, it was revealed that the addition of silver in the chemical synthesis stage increases the hydroxide utilization coefficient at fast discharges but decrease it at slow discharges. A possible mechanism that explains the influence of added silver during synthesis on discharge characteristics of hydroxide powders was proposed. The mechanism is that silver oxide, which is a semiconductor, is mixed with hydroxide and increases the specific conductivity of the powder. Increased electrical conductivity has a positive effect on charge effectiveness, because the initial phase has lower electrical conductivity than the oxidized form – NiOOH. Because the charge involves two processes – the main process of active material charging and evolution of molecular oxygen, the electrical conductivity would play a key role in the electrode charging. At low electrical conductivity and fast charge, the current would primarily be consumed by the side process of oxygen evolution. In case of slow charges, additional electrical conductivity due to the presence of silver oxide would not have a great effect on charge effectiveness, because under such conditions the own conductivity of hydroxide is sufficient. Additionally, the presence of silver oxide would decrease the hydroxide content, which in turn would decrease the utilization coefficient that is calculated from the total mass of the powder.
关键词：nickel hydroxide;alkaline secondary battery;Ni(OH)2;layered double hydroxide;silver oxide