我們平常給電池充電的時候，經常會發現，鉛酸蓄電池在充(chong)(chong)電(dian)的過程中是(shi)會發(fa)熱的，這種情況有時候很(hen)熱，有時候則相對(dui)好(hao)些。鉛酸蓄電(dian)池充(chong)(chong)電(dian)為什(shen)么(me)發(fa)熱呢？其內在原因是(shi)啥(sha)呢？下面(mian)小編就給大家對(dui)這個問(wen)題做一下解答。

1、鉛酸蓄電(dian)池充電(dian)過程的硫化化學反(fan)應發熱

鉛酸蓄電池充放電的過程是電化學反應的過程，放電時，生成硫酸鉛，充電時硫酸鉛還原為氧化鉛。
只要是鉛酸(suan)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)，在使(shi)用(yong)的(de)(de)過程中都會硫(liu)(liu)化(hua)，但(dan)其它(ta)領域的(de)(de)鉛酸(suan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)蓄(xu)池(chi)卻比電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自行(xing)車上使(shi)用(yong)的(de)(de)鉛酸(suan)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)有(you)(you)著(zhu)(zhu)更(geng)長的(de)(de)壽(shou)命，這(zhe)是因為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)車的(de)(de)鉛酸(suan)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)有(you)(you)著(zhu)(zhu)一個更(geng)容易(yi)硫(liu)(liu)化(hua)的(de)(de)工(gong)作環(huan)境。與汽(qi)車用(yong)啟動(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)不(bu)同(tong)(tong)，汽(qi)車電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)點火放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)后(hou)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)始終處(chu)于浮充(chong)(chong)狀(zhuang)態，放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)形成(cheng)的(de)(de)硫(liu)(liu)酸(suan)鉛很快又(you)被(bei)轉(zhuan)化(hua)為(wei)氧化(hua)鉛，而(er)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)車放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)(shi)，不(bu)可(ke)能同(tong)(tong)時(shi)(shi)(shi)進行(xing)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，這(zhe)就(jiu)造成(cheng)硫(liu)(liu)酸(suan)鉛大量堆集，如果(guo)深(shen)(shen)(shen)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，這(zhe)時(shi)(shi)(shi)硫(liu)(liu)酸(suan)鉛濃度更(geng)高，而(er)且電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)車騎行(xing)后(hou)很難有(you)(you)條件及時(shi)(shi)(shi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)形成(cheng)的(de)(de)硫(liu)(liu)酸(suan)鉛不(bu)能及時(shi)(shi)(shi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)轉(zhuan)化(hua)為(wei)氧化(hua)鉛，就(jiu)會形成(cheng)結(jie)晶(jing)。所以，循環(huan)壽(shou)命，根(gen)據(ju)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)深(shen)(shen)(shen)度不(bu)同(tong)(tong)而(er)差別(bie)很大，放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)深(shen)(shen)(shen)度越(yue)深(shen)(shen)(shen)，循環(huan)次數越(yue)少，放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)深(shen)(shen)(shen)度越(yue)淺，循環(huan)次數越(yue)多，發(fa)熱越(yue)嚴重(zhong)。

一些鉛酸蓄電池在做70%的1C充電和60%的2C放電中，由于采用連續大電流循環，破壞了電池生成大硫酸鉛結晶的條件，所以可能看不到鉛酸蓄電池硫化對電池的破壞。如果試驗中途停頓，鉛酸蓄電池硫化的問題就會顯現。由于電池重量大，一些用戶經常采取電池經過多次使用放完電才再次充電，這樣電池放電以后沒有及時充電，鉛酸蓄電池硫化就比較嚴重。另外，鉛酸蓄電池的硫酸比重比較高，也是鉛酸蓄電池硫化的重要因素。而鉛酸蓄電池硫化，破壞了負極板氧循環的能力，形成加速失水。
這樣，鉛酸(suan)(suan)蓄電(dian)(dian)池(chi)(chi)(chi)的硫酸(suan)(suan)比重更(geng)加(jia)(jia)高，導致更(geng)加(jia)(jia)容易導致鉛酸(suan)(suan)蓄電(dian)(dian)池(chi)(chi)(chi)硫化。所(suo)以，鉛酸(suan)(suan)蓄電(dian)(dian)池(chi)(chi)(chi)硫化的程度可(ke)能不(bu)同，但是(shi)對鉛酸(suan)(suan)蓄電(dian)(dian)池(chi)(chi)(chi)的壽命影響卻是(shi)普遍的。

2、鉛酸蓄(xu)電池使用一段時間后失水

密(mi)封鉛酸(suan)蓄(xu)(xu)電(dian)(dian)池(chi)的(de)(de)最基本(ben)原理(li)之一就是正極板(ban)析氧(yang)以后，氧(yang)氣(qi)直接到負(fu)極板(ban)與負(fu)極板(ban)的(de)(de)析氫(qing)還原為水(shui)，考核鉛酸(suan)蓄(xu)(xu)電(dian)(dian)池(chi)這(zhe)(zhe)個技術指標的(de)(de)參數叫(jiao)做”密(mi)封反應效率”，這(zhe)(zhe)種現象叫(jiao)做”氧(yang)循環”。這(zhe)(zhe)樣，鉛酸(suan)蓄(xu)(xu)電(dian)(dian)池(chi)的(de)(de)失水(shui)很少，實(shi)現了”免維護”，就是免加水(shui)。但(dan)密(mi)封鉛酸(suan)蓄(xu)(xu)電(dian)(dian)池(chi)的(de)(de)這(zhe)(zhe)種氧(yang)循環在電(dian)(dian)動自行車上卻被破壞，導致電(dian)(dian)池(chi)大量失水(shui)。

為了滿(man)足電(dian)(dian)(dian)(dian)池(chi)在(zai)8小(xiao)時以(yi)內充(chong)(chong)(chong)(chong)滿(man)電(dian)(dian)(dian)(dian)，所以(yi)在(zai)三段式恒壓(ya)(ya)限流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)中，如36伏(fu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器的恒壓(ya)(ya)為44.4伏(fu)，3個(ge)單(dan)(dan)體電(dian)(dian)(dian)(dian)池(chi)共(gong)有(you)18個(ge)單(dan)(dan)格，折合單(dan)(dan)格電(dian)(dian)(dian)(dian)壓(ya)(ya)就為2.466V。這(zhe)樣，大大超(chao)過(guo)電(dian)(dian)(dian)(dian)池(chi)正極板(ban)析(xi)氧(yang)電(dian)(dian)(dian)(dian)壓(ya)(ya)的2.35V和負極板(ban)析(xi)氫電(dian)(dian)(dian)(dian)壓(ya)(ya)的2.42V。一些充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器制(zhi)造商(shang)的產品(pin)為了降低(di)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)時間(jian)的指示，提(ti)(ti)高(gao)了恒壓(ya)(ya)轉浮充(chong)(chong)(chong)(chong)的電(dian)(dian)(dian)(dian)流(liu)，而使得(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)指示充(chong)(chong)(chong)(chong)滿(man)電(dian)(dian)(dian)(dian)以(yi)后，還沒有(you)充(chong)(chong)(chong)(chong)滿(man)電(dian)(dian)(dian)(dian)，就靠提(ti)(ti)高(gao)浮充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)壓(ya)(ya)來彌(mi)補。這(zhe)樣，很(hen)多(duo)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器的浮充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)壓(ya)(ya)超(chao)過(guo)單(dan)(dan)格電(dian)(dian)(dian)(dian)壓(ya)(ya)2.35V，這(zhe)樣在(zai)浮充(chong)(chong)(chong)(chong)階(jie)段還在(zai)大量析(xi)氧(yang)。而鉛酸(suan)蓄電(dian)(dian)(dian)(dian)池(chi)的氧(yang)循(xun)環又不(bu)好，這(zhe)樣在(zai)浮充(chong)(chong)(chong)(chong)階(jie)段也在(zai)不(bu)斷(duan)的排(pai)氣(qi)。

一(yi)組(zu)(zu)36伏鉛酸蓄電(dian)(dian)池(chi)(chi)有3個(ge)(ge)單(dan)體(ti)電(dian)(dian)池(chi)(chi)，每(mei)個(ge)(ge)單(dan)體(ti)電(dian)(dian)池(chi)(chi)有6個(ge)(ge)單(dan)格(ge)，每(mei)個(ge)(ge)單(dan)格(ge)有15塊以上正(zheng)負柵板(ban)，一(yi)組(zu)(zu)電(dian)(dian)池(chi)(chi)就最(zui)少(shao)有270個(ge)(ge)焊(han)點，如果(guo)產生千(qian)分之一(yi)的(de)虛焊(han)就會導致每(mei)4組(zu)(zu)電(dian)(dian)池(chi)(chi)必然有一(yi)組(zu)(zu)不(bu)合格(ge)，而(er)鉛鈣板(ban)非(fei)常(chang)容易因析鈣而(er)造成虛焊(han)，所以電(dian)(dian)池(chi)(chi)制造商普遍(bian)采用(yong)低銻合金(jin)板(ban)，而(er)低銻合金(jin)的(de)析氣(qi)電(dian)(dian)壓更(geng)低，電(dian)(dian)池(chi)(chi)出氣(qi)量更(geng)大，失水就更(geng)加嚴重。

浮充(chong)鉛(qian)(qian)酸(suan)(suan)蓄(xu)電(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)硫酸(suan)(suan)標準比(bi)重(zhong)(zhong)(zhong)應(ying)(ying)該在1.21~1.28之間，但為(wei)適應(ying)(ying)電(dian)(dian)(dian)動(dong)自行車(che)大容(rong)量、大電(dian)(dian)(dian)流放電(dian)(dian)(dian)的(de)(de)(de)(de)要求，電(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)硫酸(suan)(suan)比(bi)重(zhong)(zhong)(zhong)一般都在1.36~1.38左右。由于電(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)硫酸(suan)(suan)比(bi)重(zhong)(zhong)(zhong)相對(dui)(dui)高了(le)很多，所(suo)以(yi)，電(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)硫化也相對(dui)(dui)嚴重(zhong)(zhong)(zhong)。電(dian)(dian)(dian)池(chi)放電(dian)(dian)(dian)以(yi)后(hou)到(dao)第二天充(chong)電(dian)(dian)(dian)以(yi)前，硫酸(suan)(suan)比(bi)重(zhong)(zhong)(zhong)高的(de)(de)(de)(de)電(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)硫化明(ming)顯。這(zhe)樣(yang)，更(geng)加(jia)降低(di)了(le)負(fu)極板氧循(xun)環(huan)的(de)(de)(de)(de)能力。而(er)失(shi)(shi)水以(yi)后(hou)的(de)(de)(de)(de)電(dian)(dian)(dian)池(chi)，失(shi)(shi)去的(de)(de)(de)(de)主要是(shi)水，留(liu)下(xia)了(le)硫酸(suan)(suan)的(de)(de)(de)(de)成分，相當于進(jin)一步(bu)提高了(le)硫酸(suan)(suan)的(de)(de)(de)(de)比(bi)重(zhong)(zhong)(zhong)，這(zhe)樣(yang)就使(shi)鉛(qian)(qian)酸(suan)(suan)蓄(xu)電(dian)(dian)(dian)池(chi)更(geng)加(jia)容(rong)易硫化。所(suo)以(yi)，鉛(qian)(qian)酸(suan)(suan)蓄(xu)電(dian)(dian)(dian)池(chi)硫化加(jia)重(zhong)(zhong)(zhong)了(le)失(shi)(shi)水，失(shi)(shi)水又加(jia)重(zhong)(zhong)(zhong)了(le)硫化。對(dui)(dui)用(yong)戶而(er)言，”密(mi)封”是(shi)必要的(de)(de)(de)(de)，否(fou)則酸(suan)(suan)液溢出的(de)(de)(de)(de)后(hou)果不堪設(she)想，但在電(dian)(dian)(dian)動(dong)車(che)領域(yu)過份地(di)推廣(guang)”免維護”的(de)(de)(de)(de)概(gai)念是(shi)不合適的(de)(de)(de)(de)。

3、熱失控

鉛(qian)(qian)酸(suan)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)在(zai)(zai)充(chong)(chong)入(ru)電(dian)(dian)(dian)(dian)(dian)量(liang)達(da)到(dao)(dao)70%以(yi)后(hou)(hou)(hou)，鉛(qian)(qian)酸(suan)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)極(ji)化電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)相對比較高(gao)，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)副反應開(kai)始(shi)(shi)逐(zhu)(zhu)步(bu)增加，電(dian)(dian)(dian)(dian)(dian)解水開(kai)始(shi)(shi)了(le)。在(zai)(zai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)單格電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)達(da)到(dao)(dao)2.35V以(yi)后(hou)(hou)(hou)，首先正極(ji)板析(xi)(xi)(xi)氧(yang)，在(zai)(zai)達(da)到(dao)(dao)2.42V以(yi)后(hou)(hou)(hou)，負極(ji)板開(kai)始(shi)(shi)析(xi)(xi)(xi)氫(qing)。這時候充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)能(neng)轉(zhuan)變(bian)(bian)為化學能(neng)減少，轉(zhuan)變(bian)(bian)為電(dian)(dian)(dian)(dian)(dian)解水的(de)(de)(de)(de)能(neng)量(liang)增加。充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)過程(cheng)的(de)(de)(de)(de)是(shi)(shi)否析(xi)(xi)(xi)氣(qi)取(qu)決于充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，析(xi)(xi)(xi)氣(qi)量(liang)取(qu)決于達(da)到(dao)(dao)析(xi)(xi)(xi)氣(qi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)以(yi)后(hou)(hou)(hou)的(de)(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。所以(yi)，在(zai)(zai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)過程(cheng)中，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)在(zai)(zai)進入(ru)恒壓(ya)(ya)(ya)以(yi)后(hou)(hou)(hou)，電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)開(kai)始(shi)(shi)接近于最高(gao)，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)也(ye)保持限流(liu)(liu)值。這時候析(xi)(xi)(xi)氣(qi)量(liang)最大。在(zai)(zai)進入(ru)恒壓(ya)(ya)(ya)以(yi)后(hou)(hou)(hou)，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)應該(gai)逐(zhu)(zhu)步(bu)下(xia)降(jiang)，析(xi)(xi)(xi)氣(qi)量(liang)也(ye)應該(gai)逐(zhu)(zhu)步(bu)下(xia)降(jiang)。充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)本身是(shi)(shi)放熱(re)反應，一般鉛(qian)(qian)酸(suan)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)熱(re)設計是(shi)(shi)可以(yi)控制溫升的(de)(de)(de)(de)。在(zai)(zai)鉛(qian)(qian)酸(suan)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)大量(liang)析(xi)(xi)(xi)氣(qi)以(yi)后(hou)(hou)(hou)，氧(yang)氣(qi)在(zai)(zai)負極(ji)板復合為水，發熱(re)量(liang)遠遠大于充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)時的(de)(de)(de)(de)發熱(re)。密封鉛(qian)(qian)酸(suan)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)希(xi)望(wang)負極(ji)板具有良好(hao)的(de)(de)(de)(de)氧(yang)循(xun)環(huan)能(neng)力，但是(shi)(shi)，氧(yang)循(xun)環(huan)會產生發熱(re)。所以(yi)，氧(yang)循(xun)環(huan)是(shi)(shi)一把(ba)雙(shuang)刃劍(jian)，好(hao)處(chu)是(shi)(shi)減少了(le)水損失，壞處(chu)是(shi)(shi)電(dian)(dian)(dian)(dian)(dian)池(chi)會發熱(re)。

在(zai)恒壓充(chong)電(dian)(dian)(dian)的(de)條(tiao)件下，氧循環電(dian)(dian)(dian)流(liu)(liu)(liu)也參與了充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)(liu)，所(suo)以充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)(liu)下降速率放緩。而(er)鉛(qian)酸蓄電(dian)(dian)(dian)池(chi)發熱，會引(yin)起充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)(liu)下降速率更加(jia)緩慢，甚至電(dian)(dian)(dian)流(liu)(liu)(liu)反升。而(er)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)(liu)在(zai)電(dian)(dian)(dian)池(chi)發熱的(de)作用(yong)下，一旦(dan)電(dian)(dian)(dian)流(liu)(liu)(liu)反升，又增(zeng)加(jia)了發熱。這(zhe)樣，充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)(liu)一直會上升到限流(liu)(liu)(liu)值。電(dian)(dian)(dian)池(chi)發高熱，并(bing)且積(ji)累熱，一直到電(dian)(dian)(dian)池(chi)外殼(ke)發生熱軟(ruan)化變形(xing)。而(er)電(dian)(dian)(dian)池(chi)的(de)熱變形(xing)時(shi)，內部氣壓高，所(suo)以呈現電(dian)(dian)(dian)池(chi)時(shi)鼓脹(zhang)的(de)。這(zhe)就是電(dian)(dian)(dian)池(chi)熱失控而(er)損壞電(dian)(dian)(dian)池(chi)。鉛(qian)酸蓄電(dian)(dian)(dian)池(chi)一旦(dan)出(chu)現嚴重鼓脹(zhang)，漏酸和漏氣的(de)問題也出(chu)現了，鉛(qian)酸蓄電(dian)(dian)(dian)池(chi)會出(chu)現急性失效(xiao)。

誘發(fa)電(dian)(dian)池(chi)鼓脹(zhang)的原因有(you)很(hen)多(duo)。如果(guo)充(chong)電(dian)(dian)電(dian)(dian)壓(ya)高，析(xi)氣量大，會(hui)產(chan)(chan)生(sheng)熱(re)失控(kong)。如果(guo)某一(yi)組電(dian)(dian)池(chi)或者某一(yi)個單格(ge)電(dian)(dian)池(chi)發(fa)生(sheng)嚴重落后(hou)，而充(chong)電(dian)(dian)的恒壓(ya)值不變，其他的單格(ge)電(dian)(dian)池(chi)也(ye)會(hui)出現充(chong)電(dian)(dian)電(dian)(dian)壓(ya)相(xiang)對過高，也(ye)會(hui)產(chan)(chan)生(sheng)熱(re)失控(kong)問題。為降低(di)電(dian)(dian)池(chi)的熱(re)失控(kong)機率，很(hen)多(duo)充(chong)電(dian)(dian)器廠家(jia)將(jiang)恒壓(ya)值降低(di)至43伏(fu)，這也(ye)必然導致欠充(chong)。

導致鉛酸蓄電(dian)池(chi)(chi)(chi)充(chong)(chong)電(dian)發熱(re)的(de)另一(yi)個原(yuan)因就是硫化，硫化直(zhi)接導致電(dian)池(chi)(chi)(chi)內阻增加，這就進一(yi)步造成鉛酸蓄電(dian)池(chi)(chi)(chi)充(chong)(chong)電(dian)發熱(re)，發熱(re)又(you)使氧循環(huan)電(dian)流上升，所以硫化嚴(yan)重的(de)電(dian)池(chi)(chi)(chi)，熱(re)失控發生(sheng)的(de)機率很大。

4、活性物質(zhi)脫落、極板(ban)軟化

造成活性(xing)物質(zhi)脫落的原(yuan)因很多：

（1）鉛酸蓄電池極(ji)板活性物質分(fen)布(bu)不(bu)均勻，造成放(fang)電時(shi)膨脹張力不(bu)同而(er)脫落。

（2）鉛(qian)酸(suan)蓄電(dian)池過放電(dian)欠壓時(shi)，β-PbO2大量減少，α-PbO2就會參與放電(dian)反應生成硫酸(suan)鉛(qian)。

（3）硫(liu)化(hua)結(jie)晶在極(ji)板(ban)上生長的(de)(de)膨脹張力(li)也會導致(zhi)活性物質脫(tuo)落(luo)。正(zheng)極(ji)板(ban)一旦出現軟化(hua)，起到支持作用(yong)的(de)(de)多孔結(jie)構(gou)就(jiu)(jiu)被(bei)破壞了(le)，正(zheng)極(ji)板(ban)的(de)(de)多孔被(bei)電(dian)池(chi)極(ji)板(ban)的(de)(de)壓(ya)力(li)壓(ya)實(shi)了(le)，就(jiu)(jiu)降(jiang)低了(le)參(can)與(yu)反應的(de)(de)真實(shi)面積，鉛酸蓄(xu)電(dian)池(chi)容量就(jiu)(jiu)下降(jiang)了(le)。這樣(yang)，防止(zhi)過放(fang)電(dian)、抑制和消除(chu)硫(liu)化(hua)是控制正(zheng)極(ji)板(ban)軟化(hua)的(de)(de)重要措(cuo)施(shi)。放(fang)電(dian)的(de)(de)時候，每次放(fang)電(dian)，或多或少(shao)的(de)(de)總要有一點點α-PbO2參(can)與(yu)反應。

所以，一個正(zheng)常(chang)使(shi)用(yong)的(de)鉛(qian)酸(suan)蓄電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)，在不失(shi)水(shui)也不硫化，也沒有過(guo)放(fang)(fang)電(dian)(dian)(dian)(dian)的(de)情況下，電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)壽(shou)命(ming)就取決于正(zheng)極(ji)板(ban)(ban)軟(ruan)化。電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)容量(liang)(liang)(liang)受(shou)活(huo)性物質(zhi)和利用(yong)率影(ying)響。電(dian)(dian)(dian)(dian)動車鉛(qian)酸(suan)蓄電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)外形(xing)尺寸一定，極(ji)板(ban)(ban)的(de)質(zhi)量(liang)(liang)(liang)已(yi)被(bei)限制到一定的(de)程度，只(zhi)有提高活(huo)性物質(zhi)的(de)利用(yong)率，才能提高容量(liang)(liang)(liang)。要提高鉛(qian)酸(suan)蓄電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)容量(liang)(liang)(liang)，必然增加孔率，提高PbO2含(han)量(liang)(liang)(liang)、硫酸(suan)比(bi)重，但是這些措施(shi)都會(hui)加速正(zheng)極(ji)板(ban)(ban)的(de)軟(ruan)化，造成鉛(qian)酸(suan)蓄電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)壽(shou)命(ming)加速衰減，充(chong)放(fang)(fang)電(dian)(dian)(dian)(dian)過(guo)程中活(huo)性物質(zhi)會(hui)產生膨(peng)脹、收(shou)縮(特別是正(zheng)極(ji)板(ban)(ban))，放(fang)(fang)電(dian)(dian)(dian)(dian)深(shen)度越深(shen)，活(huo)性物質(zhi)膨(peng)脹收(shou)縮量(liang)(liang)(liang)越大，更加速活(huo)性物質(zhi)軟(ruan)化。因(yin)此，初始容量(liang)(liang)(liang)偏(pian)大時直(zhi)接(jie)影(ying)響鉛(qian)酸(suan)蓄電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)壽(shou)命(ming)。

總(zong)結：上(shang)面(mian)(mian)所有(you)的(de)內(nei)(nei)(nei)阻(zu)(zu)原(yuan)因(yin)都是導(dao)致鉛(qian)酸蓄(xu)電(dian)(dian)池(chi)(chi)充電(dian)(dian)發(fa)熱(re)的(de)內(nei)(nei)(nei)因(yin)，而總(zong)之一句話(hua)，上(shang)面(mian)(mian)的(de)原(yuan)因(yin)會(hui)導(dao)致鉛(qian)酸蓄(xu)電(dian)(dian)池(chi)(chi)內(nei)(nei)(nei)阻(zu)(zu)增(zeng)大，電(dian)(dian)流通過增(zeng)大的(de)內(nei)(nei)(nei)阻(zu)(zu)就(jiu)會(hui)產生更多(duo)的(de)熱(re)量，體現(xian)出來就(jiu)是發(fa)熱(re)的(de)現(xian)象了。