摘要
γ－ＮｉＯＯＨ 是β－Ｎｉ（ＯＨ）２ 的过充电产物，它是在大电流充放电和高电解液浓度等条件下形成的［１］。电极中γ－ＮｉＯＯＨ的生成将导致电极的膨胀（由β－Ｎｉ（ＯＨ）２ 转变成γ－ＮｉＯＯＨ，体积增加４４％ ），使其机械稳定性变差和容量衰减，从而加速了电极的老化和循环寿命的缩短。采用参考强度计算法可以直接、无损地测定氢氧化镍电极材料中γ相的含量，为电极材料的研制与性能控制，提供了重要的参数依据。根据正极材料中存在相的晶体结构参数和原子位置，计算得γ－ＮｉＯＯＨ 的（００３）衍射强度与β－ＮｉＯＯＨ 的（００１）衍射强度之比的参考强度Ｋ＝ ２．８３。
As the overcharge product of β Ni(OH) 2, γ NiOOH was formed under the condition of charge/discharge at high current rate and high concentration of electrolyte. Its formation caused the swelling of the nickel electrode, that is, the volume of electrode increased 44% when β Ni(OH) 2 transformed into γ NiOOH. The swelling decreased mechanical stability and capacity of electrode and then accelerated its ageing and shorten its cycle life. By using the “reference intensity ratio” method, the content of γ phase in nickel electrode was measured directly and the important parameter for the research and propriety control of electrode materials was provided. According to the parameter of unit cell structure and the atomic positions of the existing phase in positive material, the reference intensity of the ratio of the γ NiOOH (003) to the diffraction intensity of β NiOOH (001) was calculated as K=2.83.
出处
《电源技术》
CAS
CSCD
北大核心
1999年第6期328-331,共4页
Chinese Journal of Power Sources
基金
国家自然科学基金!59872006
关键词
电极材料
Γ-NIOOH
定量相分析
氢氧化镍
electrode material
γ NiOOH
quantitative phase analysis
electrochemical activity
swelling
