在電池行業,三元鋰電池憑借著眾多的優勢迅速的占領了市場,并逐漸取代傳統鉛酸蓄電池。對于傳統電池來說,三元鋰電池具有壽命長,節能環保無污染,維護成本低,充放電完全,重量輕等等優勢。我們總說三元鋰電池壽命長,那三元鋰電池壽命循環到底是多少次呢?
什么是三元鋰電池?
在自然界中,鋰(li)(li)(li)(li)(li)元(yuan)素(su)是(shi)(shi)最輕的(de)(de)(de)(de),原(yuan)子(zi)質量(liang)最小(xiao)的(de)(de)(de)(de)金屬(shu)(shu),它的(de)(de)(de)(de)原(yuan)子(zi)量(liang)為(wei)6.94g/mol,ρ=0.53g/cm3。鋰(li)(li)(li)(li)(li)化學(xue)性(xing)質活(huo)潑,極(ji)易失去電(dian)子(zi)被氧(yang)化為(wei)Li+,因此(ci)標準電(dian)極(ji)電(dian)位*負,為(wei)-3.045V,電(dian)化學(xue)當量(liang)*小(xiao),為(wei)0.26g/Ah,鋰(li)(li)(li)(li)(li)元(yuan)素(su)的(de)(de)(de)(de)這(zhe)些特點決(jue)定了(le)它是(shi)(shi)一種具有(you)很高(gao)比(bi)能量(liang)的(de)(de)(de)(de)材料。三元(yuan)鋰(li)(li)(li)(li)(li)電(dian)池是(shi)(shi)指采(cai)用鎳鈷錳三種過(guo)渡金屬(shu)(shu)氧(yang)化物(wu)為(wei)正極(ji)材料的(de)(de)(de)(de)鋰(li)(li)(li)(li)(li)二次(ci)電(dian)池。它充分綜合了(le)鈷酸鋰(li)(li)(li)(li)(li)良好的(de)(de)(de)(de)循環性(xing)能、鎳酸鋰(li)(li)(li)(li)(li)的(de)(de)(de)(de)高(gao)比(bi)容量(liang)和(he)錳酸鋰(li)(li)(li)(li)(li)的(de)(de)(de)(de)高(gao)安全(quan)性(xing)及低(di)成本等特點,利用分子(zi)水(shui)平混(hun)合、摻雜、包(bao)覆和(he)表面(mian)修飾(shi)等方(fang)法合成鎳鈷錳等多元(yuan)素(su)協同的(de)(de)(de)(de)復合嵌鋰(li)(li)(li)(li)(li)氧(yang)化物(wu),是(shi)(shi)目前被廣泛研究(jiu)和(he)應用的(de)(de)(de)(de)一種鋰(li)(li)(li)(li)(li)離子(zi)可(ke)充電(dian)電(dian)池。
三元鋰電池壽命
所謂鋰電(dian)(dian)(dian)(dian)池(chi)壽命是指電(dian)(dian)(dian)(dian)池(chi)在使用(yong)過一段時(shi)間后,容量(liang)(liang)衰(shuai)減為標(biao)稱容量(liang)(liang)(室(shi)溫25℃,標(biao)準大氣壓,且以(yi)0.2C放(fang)電(dian)(dian)(dian)(dian)的(de)(de)電(dian)(dian)(dian)(dian)池(chi)容量(liang)(liang))的(de)(de)70%,即可認為壽命終止。行業(ye)內一般以(yi)鋰電(dian)(dian)(dian)(dian)池(chi)滿充滿放(fang)的(de)(de)循(xun)(xun)環(huan)次數來計(ji)算(suan)循(xun)(xun)環(huan)壽命。在使用(yong)的(de)(de)過程中,鋰電(dian)(dian)(dian)(dian)池(chi)內部會發生不可逆的(de)(de)電(dian)(dian)(dian)(dian)化學反應導(dao)致容量(liang)(liang)下降,比如(ru)電(dian)(dian)(dian)(dian)解液的(de)(de)分解,活性材(cai)料的(de)(de)失活,正負極(ji)結構的(de)(de)坍塌(ta)導(dao)致鋰離子嵌入和脫嵌的(de)(de)數量(liang)(liang)減少(shao)等(deng)等(deng)。實驗(yan)標(biao)明(ming),更高倍率的(de)(de)放(fang)電(dian)(dian)(dian)(dian)會導(dao)致容量(liang)(liang)更快的(de)(de)衰(shuai)減,如(ru)果放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流較(jiao)低,電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)壓會接近平衡(heng)電(dian)(dian)(dian)(dian)壓,能釋放(fang)出更多(duo)的(de)(de)能量(liang)(liang)。
三(san)元鋰(li)(li)電(dian)(dian)池(chi)的理論壽(shou)(shou)命約為800次(ci)(ci)循(xun)環(huan)(huan),在商業化的可充電(dian)(dian)鋰(li)(li)電(dian)(dian)池(chi)中屬于(yu)中等(deng)。磷酸(suan)鐵鋰(li)(li)約為2000次(ci)(ci),而鈦酸(suan)鋰(li)(li)據說(shuo)可以達到1萬(wan)次(ci)(ci)循(xun)環(huan)(huan)。目前主流(liu)的電(dian)(dian)池(chi)廠家在其生產的三(san)元電(dian)(dian)芯規格書中承(cheng)諾大于(yu)500次(ci)(ci)(標準條件下充放(fang)電(dian)(dian)),但是(shi)(shi)電(dian)(dian)芯在配(pei)組做成(cheng)電(dian)(dian)池(chi)包后,由于(yu)一致性問題,主要是(shi)(shi)電(dian)(dian)壓和(he)內(nei)阻(zu)不(bu)可能完全(quan)一樣,其循(xun)環(huan)(huan)壽(shou)(shou)命大約為400次(ci)(ci)。廠家推薦SOC使用窗(chuang)口為10%~90%,不(bu)建議進行深度充放(fang)電(dian)(dian),不(bu)然會對(dui)電(dian)(dian)池(chi)的正負(fu)極結構造成(cheng)不(bu)可逆的損傷,若是(shi)(shi)以淺(qian)充淺(qian)放(fang)來(lai)計算的話,循(xun)環(huan)(huan)壽(shou)(shou)命至(zhi)少有1000次(ci)(ci)。另外,鋰(li)(li)電(dian)(dian)池(chi)若是(shi)(shi)經常在高倍率和(he)高溫環(huan)(huan)境下放(fang)電(dian)(dian),電(dian)(dian)池(chi)壽(shou)(shou)命會大幅下降到不(bu)足200次(ci)(ci)。