同鎳鎘電池相比，鎳氫電池具有以下顯著優點：

1）能量密度高，同尺寸電池(chi)(chi)，容量是鎳鎘電池(chi)(chi)的1.5~2倍。

2）環境相(xiang)容性好，無鎘污染，

3）可(ke)大電流快速充放電，充放電倍率(lv)高。

4）無明顯(xian)的記憶效應。

5）低溫性能(neng)好，耐過充放能(neng)力(li)強(qiang)。

6）工(gong)作電壓與鎳鎘電池相同，為(wei)1.2V。

鎳氫電(dian)(dian)(dian)池(chi)是鎳鎘電(dian)(dian)(dian)池(chi)的(de)換代產品，電(dian)(dian)(dian)池(chi)的(de)物理參數，如(ru)尺寸、質量和外(wai)觀完全可與鎳鎘電(dian)(dian)(dian)池(chi)互(hu)換，電(dian)(dian)(dian)性能(neng)也基本一致，充放(fang)電(dian)(dian)(dian)曲線相似，放(fang)電(dian)(dian)(dian)曲線非常平(ping)滑，電(dian)(dian)(dian)快要消耗完時，電(dian)(dian)(dian)壓才會突然下降，故使(shi)用時完全可替代鎳鎘電(dian)(dian)(dian)池(chi)，而(er)不(bu)需(xu)要對(dui)設備進行任何改造。

鎳氫電(dian)池(chi)的(de)缺點(dian)是(shi)自(zi)放電(dian)與壽命不如(ru)鎳鎘電(dian)池(chi)，但也能達到(dao)500次循環壽命和國(guo)際電(dian)工委員會的(de)推薦(jian)標準。

吸氫電(dian)(dian)(dian)極自(zi)(zi)放(fang)(fang)電(dian)(dian)(dian)包括可逆自(zi)(zi)放(fang)(fang)電(dian)(dian)(dian)和不可逆自(zi)(zi)放(fang)(fang)電(dian)(dian)(dian)。

可(ke)逆自(zi)放電(dian)(dian)的主(zhu)要原(yuan)因在于環境(jing)壓力低(di)于電(dian)(dian)極(ji)(ji)中(zhong)金屬氫(qing)(qing)化(hua)物的平衡氫(qing)(qing)壓，氫(qing)(qing)氣(qi)(qi)會(hui)從(cong)電(dian)(dian)極(ji)(ji)中(zhong)脫附出來。當(dang)吸氫(qing)(qing)電(dian)(dian)極(ji)(ji)與(yu)氧化(hua)鎳(nie)正(zheng)極(ji)(ji)組成(cheng)MH/Ni電(dian)(dian)池(chi)時，這些逸(yi)出的氫(qing)(qing)氣(qi)(qi)與(yu)正(zheng)極(ji)(ji)活性物質(zhi)NiOOH反應生成(cheng)Ni（OH）2，形成(cheng)放電(dian)(dian)反應，該(gai)部(bu)分自(zi)放電(dian)(dian)可(ke)以通過再充電(dian)(dian)復(fu)原(yuan)。

不可逆自放(fang)電(dian)主要是由于負極的(de)化(hua)學或電(dian)化(hua)學因素所引起。如(ru)合金(jin)表面(mian)電(dian)勢(shi)較低(di)的(de)稀土(tu)元素與電(dian)解液反應形成(cheng)(cheng)氫(qing)氧化(hua)物等，例如(ru)Pb稀土(tu)在表面(mian)偏析，并生成(cheng)(cheng)La（OH）；，使(shi)合金(jin)組成(cheng)(cheng)發生變化(hua)，吸氫(qing)能(neng)力(li)下降，這種吸氫(qing)能(neng)力(li)下降無法用充電(dian)方(fang)法復原。