放電行為的影響
陳宗璋1，余 剛1，李素芳1， 許檢紅2
( 1. 湖南大學(xué) 化學(xué)化工學(xué)院，長(zhǎng)沙 410082；
2. 湖南省神舟科技股份有限公司，長(zhǎng)沙 410004;
3. 湖南大學(xué) 機(jī)械與汽車工程學(xué)院，長(zhǎng)沙 410082)
摘 要: 采用恒電流充放電法、交流阻抗法、循環(huán)伏安法研究了固液空間比對(duì)粘結(jié)式Ni(OH)2電極放電行為的影響，通過(guò)掃描電鏡（SEM）觀察了電極的表面形貌。結(jié)果表明：在單位面積活性物質(zhì)載量一定的條件下，電極較厚，則活性物質(zhì)顆粒之間的間隙較多；隨著固液空間比的不斷下降，Warburg擴(kuò)散區(qū)的擴(kuò)散速度加快，但電極的充電效率降低，放電容量減少，活性物質(zhì)利用率減小，電荷轉(zhuǎn)移電阻增大，填充密度增大到一定程度時(shí)，液相傳質(zhì)已經(jīng)不容忽略。
關(guān)鍵字: Ni(OH)2電極；固液空間比；放電；填充密度；液相傳質(zhì)
CHEN Zong-zhang1，YU Gang1，
LI Su-fang1，XU Jian-hong2
（ 1. College of Chemistry and Chemical Engineering， Hunan University, Changsha 410082，China;
2. Hunan Shenzhou Science and Technology Stock Limited Company，Changsha 410004，China;
3. College of Mechanical and Automotive Engineering，Hunan University， Changsha 410082 ，China）
Abstract: The effect of solid-to-liquid space ratio on the discharging behavior of pasted Ni(OH)2 electrodes were investigated by galvanostatic charge-discharge，electrochemical impedance spectroscopy，cyclic voltammetry. The morphologies of the electrodes were observed by SEM. The more clearances were found between the active material grains for the thicker electrodes when the active material loading per unit area was a constant. Experimental results show the faster diffusion rate at Warburg zero，but，lower charge efficiency，less discharge capacity，smaller active material utilization，larger charge transfer resistance with the decrease of the solid-to-liquid space ratio for the Ni(OH)2 electrodes. The mass transfer of the solution phase could not be ignored when the active material loading density was increased to some extent.
Key words: Ni(OH)2 electrodes; solid-to-liquid space ratio; discharging; loading density; mass transfer of the solution phase
