鋰離子電池具有重量輕、容量大、無記憶效應等優點,因而得到了普遍應用——現在的許多數碼設備都采用了鋰離子電池作電源,盡管其價格相對來說比較昂貴。鋰離子電池的(de)(de)能(neng)量(liang)密(mi)度很(hen)高,它的(de)(de)容量(liang)是同重(zhong)量(liang)的(de)(de)鎳氫電(dian)池的(de)(de)1.5~2倍,而且(qie)具有很(hen)低的(de)(de)自放電(dian)率。此外,鋰離(li)子電(dian)池幾乎(hu)沒有“記憶效應(ying)”以(yi)及不含有毒(du)物質等優點也(ye)是它廣泛應(ying)用(yong)的(de)(de)重(zhong)要原因(yin)。
當(dang)對電(dian)(dian)(dian)(dian)池(chi)(chi)進行(xing)充電(dian)(dian)(dian)(dian)時(shi),電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)正(zheng)極(ji)上(shang)有(you)鋰離(li)(li)(li)子(zi)生成,生成的(de)鋰離(li)(li)(li)子(zi)經(jing)過電(dian)(dian)(dian)(dian)解液運(yun)動到(dao)負(fu)極(ji)。而作為負(fu)極(ji)的(de)碳(tan)(tan)呈層狀結構(gou),它有(you)很(hen)多微孔,達到(dao)負(fu)極(ji)的(de)鋰離(li)(li)(li)子(zi)就(jiu)嵌入到(dao)碳(tan)(tan)層的(de)微孔中(zhong),嵌入的(de)鋰離(li)(li)(li)子(zi)越多,充電(dian)(dian)(dian)(dian)容(rong)量越高。同樣,當(dang)對電(dian)(dian)(dian)(dian)池(chi)(chi)進行(xing)放(fang)電(dian)(dian)(dian)(dian)時(shi)(即我們使用電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)過程),嵌在負(fu)極(ji)碳(tan)(tan)層中(zhong)的(de)鋰離(li)(li)(li)子(zi)脫出,又運(yun)動回正(zheng)極(ji)。回正(zheng)極(ji)的(de)鋰離(li)(li)(li)子(zi)越多,放(fang)電(dian)(dian)(dian)(dian)容(rong)量越高。
一(yi)(yi)般(ban)鋰(li)電(dian)(dian)(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流設定(ding)在(zai)0.2C至1C之間,電(dian)(dian)(dian)(dian)(dian)(dian)流越大,充電(dian)(dian)(dian)(dian)(dian)(dian)越快,同(tong)時電(dian)(dian)(dian)(dian)(dian)(dian)池發熱也越大。而且,過大的電(dian)(dian)(dian)(dian)(dian)(dian)流充電(dian)(dian)(dian)(dian)(dian)(dian),容(rong)量不夠滿(man),因為電(dian)(dian)(dian)(dian)(dian)(dian)池內部的電(dian)(dian)(dian)(dian)(dian)(dian)化(hua)學(xue)反應(ying)需要時間。就跟倒啤酒一(yi)(yi)樣,倒太快的話會產生泡沫,反而不滿(man)。對電(dian)(dian)(dian)(dian)(dian)(dian)池來(lai)說,正常使用(yong)就是放電(dian)(dian)(dian)(dian)(dian)(dian)的過程。
鋰(li)電(dian)池放電(dian)需(xu)要(yao)注(zhu)意幾(ji)點:
第一,放電電流不能過大,過大的電流導致電池內部發熱,有可能會造成永久性的損害。在手機上,這個倒是沒有問題的,可(ke)以不考(kao)慮。
第二,絕對不能過(guo)(guo)放(fang)電(dian)(dian)(dian)!鋰電(dian)(dian)(dian)池(chi)最怕過(guo)(guo)放(fang)電(dian)(dian)(dian),一(yi)旦放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)壓低(di)于2.7V,將可能導(dao)致(zhi)電(dian)(dian)(dian)池(chi)報廢。好在手機電(dian)(dian)(dian)池(chi)內部都已(yi)經裝了(le)保護電(dian)(dian)(dian)路(lu),電(dian)(dian)(dian)壓還(huan)沒低(di)到損壞電(dian)(dian)(dian)池(chi)的(de)程度,保護電(dian)(dian)(dian)路(lu)就會起作用,停止放(fang)電(dian)(dian)(dian)。從圖上(shang)可以看出(chu),電(dian)(dian)(dian)池(chi)放(fang)電(dian)(dian)(dian)電(dian)(dian)(dian)流越大(da),放(fang)電(dian)(dian)(dian)容量越小,電(dian)(dian)(dian)壓下降更快。
鋰離子電池優點
鋰離(li)(li)子(zi)(zi)電(dian)(dian)(dian)池(Li-ion,Lithium Ion Battery):鋰離(li)(li)子(zi)(zi)電(dian)(dian)(dian)池具(ju)(ju)有(you)(you)(you)重量輕、容量大、無記(ji)憶(yi)效(xiao)應(ying)(ying)等優點(dian)(dian),因(yin)而(er)得到了普遍應(ying)(ying)用——現(xian)在的(de)(de)許多數碼(ma)設備(bei)都(dou)采用了鋰離(li)(li)子(zi)(zi)電(dian)(dian)(dian)池作電(dian)(dian)(dian)源,盡管其價格相(xiang)對來說比(bi)較昂貴。鋰離(li)(li)子(zi)(zi)電(dian)(dian)(dian)池的(de)(de)能量密度很高(gao),它的(de)(de)容量是同重量的(de)(de)鎳氫電(dian)(dian)(dian)池的(de)(de)1.5~2倍,而(er)且(qie)具(ju)(ju)有(you)(you)(you)很低的(de)(de)自放(fang)電(dian)(dian)(dian)率。此外(wai),鋰離(li)(li)子(zi)(zi)電(dian)(dian)(dian)池幾(ji)乎沒有(you)(you)(you)“記(ji)憶(yi)效(xiao)應(ying)(ying)”以及不含有(you)(you)(you)毒物(wu)質等優點(dian)(dian)也是它廣泛應(ying)(ying)用的(de)(de)重要原因(yin)。
另外(wai)(wai)請注意鋰電池外(wai)(wai)部一(yi)般標(biao)有英文7.2V lithiumion battery(鋰電池)或(huo)7.2V lithium secondary battery(鋰二(er)次電池)、7.2V lithiumion rechargeable battery(充(chong)電鋰電池),所以用戶在購買電池時一(yi)定要(yao)看清(qing)(qing)電池塊外(wai)(wai)表的標(biao)志,防止因為沒有看清(qing)(qing)電池類型而(er)將鎘(ge)鎳、氫鎳電池誤認(ren)為鋰電池。
無記憶效(xiao)應(ying)大大方(fang)便了手機(ji)用(yong)戶,用(yong)戶不必(bi)在每次充(chong)電(dian)(dian)時都先放電(dian)(dian)再(zai)充(chong)電(dian)(dian),而可以隨心所欲的隨時對(dui)手機(ji)充(chong)電(dian)(dian)。
鋰離子電池缺點
鋰(li)電池的(de)缺點是價格昂(ang)貴,所以目前尚不能普遍(bian)應用(yong),主要應用(yong)于掌(zhang)上計算機、PDA、通信設備、照相機、衛星、導(dao)彈、魚雷、儀器等(deng)。隨著技術的(de)發展(zhan)、工藝的(de)改進及生(sheng)產量的(de)增加,鋰(li)電池的(de)價格將會(hui)不斷(duan)地下降,應用(yong)上也會(hui)更普遍(bian)。
鋰離(li)子電池應(ying)用注(zhu)意事項(xiang)除與上述不可充電的鋰電池相同外,在(zai)充電方面還應(ying)注(zhu)意以下幾點:
1. 鋰離子電(dian)池有(you)4.1V及4.2V終(zhong)止(zhi)充(chong)(chong)電(dian)的(de)(de)不(bu)同(tong)(tong)品種,因(yin)此在(zai)充(chong)(chong)電(dian)時注意的(de)(de)是4.1V的(de)(de)電(dian)池不(bu)能(neng)用4.2V的(de)(de)充(chong)(chong)電(dian)器充(chong)(chong)電(dian),否(fou)則會(hui)有(you)過充(chong)(chong)的(de)(de)危(wei)險(4.1V與4.2V的(de)(de)充(chong)(chong)電(dian)器用的(de)(de)充(chong)(chong)電(dian)器IC是不(bu)同(tong)(tong)的(de)(de)!)。
2. 對電(dian)池(chi)充電(dian)時,其環境溫(wen)度(du)不能超(chao)過產品(pin)特性表(biao)中所列的溫(wen)度(du)范圍。
3. 不(bu)能反向充電。
4. 不能(neng)用充(chong)鎳鎘電(dian)池(chi)的充(chong)電(dian)器(充(chong)三節鎳鎘電(dian)池(chi)的)來(lai)充(chong)鋰離子電(dian)池(chi)(雖然額定電(dian)壓一(yi)樣,都是(shi)3.6V),但充(chong)電(dian)方式不同,容(rong)易造成(cheng)過(guo)充(chong)。
鋰(li)原電(dian)(dian)池(chi)自放電(dian)(dian)很低(di),可(ke)保存(cun)3年之久,在冷藏的(de)(de)條件下(xia)保存(cun),效果會(hui)更好。將鋰(li)原電(dian)(dian)池(chi)存(cun)放在低(di)溫的(de)(de)地方,不失是一個好方法。鋰(li)離(li)子電(dian)(dian)池(chi)在20℃下(xia)可(ke)儲存(cun)半年以(yi)上,這(zhe)是由于它(ta)的(de)(de)自放電(dian)(dian)率很低(di),而且大部分容量可(ke)以(yi)恢復。
鋰電池存(cun)(cun)在的(de)自放(fang)電(dian)(dian)現(xian)象(xiang),如(ru)果電(dian)(dian)池電(dian)(dian)壓(ya)在3.6V以下長(chang)時(shi)間保存(cun)(cun),會(hui)導致電(dian)(dian)池過放(fang)電(dian)(dian)而破壞電(dian)(dian)池內部結構,減少電(dian)(dian)池壽命(ming)。因此長(chang)期保存(cun)(cun)的(de)鋰(li)(li)電(dian)(dian)池應當每3~6個月補電(dian)(dian)一(yi)次,即充電(dian)(dian)到(dao)電(dian)(dian)壓(ya)為(wei)(wei)3.8~3.9V(鋰(li)(li)電(dian)(dian)池最(zui)佳儲存(cun)(cun)電(dian)(dian)壓(ya)為(wei)(wei)3.85V左右)為(wei)(wei)宜(yi),不(bu)宜(yi)充滿。
鋰電池的(de)(de)應(ying)用溫(wen)度范圍很廣,在北方的(de)(de)冬天(tian)室外,仍然可以使用,但容量會降(jiang)低(di)很多,如(ru)果回到室溫(wen)的(de)(de)條(tiao)件下,容量又可以恢復(fu)。