摘要
MHNi电池放电电压平台是一个十分复杂的问题,涉及电极材料、制作工艺及添加剂等多种因素。由于MHNi电池工作机理是基于电化学反应过程,因此这些因素的影响最终会通过电化学反应反映到电池的放电性能上。从电化学角度利用暂态测试技术———电流阶跃法对MHNi电池放电过程中影响电压变化的因素进行了研究,初步弄清了造成MHNi电池1.2V电压平台衰减的电化学原因。结果表明,MHNi电池的重要电化学参数———欧姆内阻与放电电压平台有着重要关系。不同欧姆内阻的MHNi电池,其1.2V放电电压平台衰减规律不尽相同。对于欧姆内阻较小的电池,1.2V放电电压平台主要由非欧姆极化控制;欧姆内阻较大的电池,1.2V放电电压平台主要由欧姆极化控制;欧姆内阻介于二者之间时,1.2V放电电压平台由欧姆极化和非欧姆极化联合控制。研究中还发现,放电进入末期时,MHNi电池的非欧姆极化急剧上升导致电池电压迅速下降到放电截止电压。
Discharge voltage plateau of Ni MH battery relates to many factors, such as electrode materials, manufacturing process and additives. All the factors effect discharge performance of battery through electrochemical reaction because the working mechanism of Ni MH battery is based on electrochemical reaction process. The voltage decay of sealed Ni MH battery caused by ohmic and non ohmic polarizations was investigated by current step method, a transient technique. The results show that the 1.2 V plateau decay of the battery with lower ohmic resistance is mainly controlled by non ohmic polarization as well as the battery with higher ohmic resistance is dominated by ohmic polarization. If the ohmic resistance is medium, the 1.2 V plateau decay is commended by both ohmic and non ohmic polarizations. Therefore, the method for prolonging the plateau must be selected according to characteristic of battery.
出处
《电源技术》
EI
CAS
CSCD
北大核心
2000年第1期22-24,共3页
Chinese Journal of Power Sources
基金
国家自然科学基金!资助项目 (596740 30 )
关键词
NH-Ni电池
电压平台
放电
电化学
Ni-MH battery
plateau decay
ohmic polarization
non ohmic polarization
1.2 V plateau
