镍电极掺杂[x(Y_2O_3)+y(Er_2O_3)]的MH/Ni电池性能研究

Study on Performance of MH/Ni Batteries Having Nickel Electrodes Doped with [x(Y_2O_3)+y(Er_2O_3)]

研究了在镍电极活性物质中掺杂一定量的[x（Y2O3）＋y（Er2O3）]（x＋y=1，其中x=0，0．5，1．0）对MH／Ni电池的性能影响。利用不同环境温度（25℃～55℃）下恒流充放电、高温（65℃）放电态搁置等方法测试了电池的性能。结果表明，常温下镍电极掺杂[x（Y2O3）＋y（Er2O3）]的MH／Ni电池的放电容量和放电平台比未掺杂的电池稍低，但随温度的升高，它的放电容量和高温储存性能等均明显优于未掺杂的电池，镍电极掺杂[x（Y2O3）＋Y（Er2O3）]提高了MH／Ni电池的高温性能。常温下，电池以1C，100％DOD循环200周后，镍电极掺杂[x（Y2O3）＋y（Er2O3）]的MH／Ni电池容量损失较少，利用X射线衍射（XRD）、交流内阻分析结果表明，镍电极活性物质循环后的相结构差别不大，但掺杂的电池循环前后内阻变化较小。综合实验结果，当x=0．5时，电池的性能最佳。

The nickel-metal hydride （Ni/MH）secondary batteries having nickel positive electrode doped with a mixture of [x（Y2O3）＋y（Er2O3）]（x＋y= 1 ,x =0,0. 5,1.0） had been prepared. Constant current charge/discharge tests at 25-55℃ and shelving at discharge state at 65℃ were tested to characterize the electrochemical performance of the Ni/MH batteries. The experimental results showed that the discharge capacity and plateau of the Ni/MH batteries,their nickel electrode doped with the [x（Y2O3）＋y（Er2O3）], were slightly lower than that of the conventional Ni/MH batteries at room temperature. However, the measured discharge characteristics and storage performance were much higher than that of the conventional Ni/MH batteries at high temperature. The high temperature performance of the Ni/MH batteries was improved due to adding [x（Y2O3）＋y（Er2O3）]in nickel positive electrode. The capacity of the Ni/MH batteries lost lower than that the conventional Ni/MH batteries after 1C, 100% DOD, charge/ discharge cycling 200 times at room temperature. Better cycle characteristics due to lower internal impedance changing before and after cycling, stable structure of the nickel positive active material by using AC internal impedance and X-ray diffraction analysis. When the value of x was 0. 5 through testing results, the characteristics of the batteries were best.