①石(dan)墨(mo)負(fu)極(ji)的(di)過(guo)充(chong)反(fan)應(ying):
②正(zheng)極(ji)過(guo)充(chong)反(fan)應(ying):
③電(dian)解(xie)液(ye)在(zai)過(guo)充(chong)時(shi)氧(yang)化(hua)反(fan)應(ying)。
電(dian)池(chi)在(zai)過(guo)充(chong)時(shi),鏗(keng)離(li)子(zi)容(rong)易(yi)還(huan)原(yuan)沉(chen)積(ji)在(zai)負(fu)極(ji)表(biao)而(er):Li++e->Li (s)沉(chen)積(ji)的(di)鏗(keng)包(bao)覆(fu)在(zai)負(fu)極(ji)表(biao)而(er),阻(zu)塞(se)了(liao)鋰(li)的(di)嵌(kan)入(ru).導(dao)致(zhi)放(fang)電(dian)效(xiao)率(shuai)降(xiang)低(di)和(hu)容(rong)量(liang)損(sun)失(shi),原(yuan)因(yin)有(you):
①可(ke)循(xun)環(huan)鋰(li)量(liang)減(jian)少(shao):
②沉(chen)積(ji)的(di)金(jin)屬(zhu)鋰(li)與(yu)溶(rong)劑(ji)或(huo)支(zhi)持(chi)電(dian)解(xie)質(zhi)反(fan)應(ying)形(xing)成(cheng)Li2CO3, LiF或(huo)其(qi)他(ta)產(chan)物(wu):
③金(jin)屬(zhu)鋰(li)通(tong)常(chang)形(xing)成(cheng)於(yu)負(fu)極(ji)與(yu)隔(ge)膜(mo)之(zhi)間(jian),可(ke)能(neng)阻(zu)塞(se)隔(ge)膜(mo)的(di)孔(kong)隙(xi)增(zeng)大(dai)電(dian)池(chi)內(nei)阻(zu)。
快(kuai)速(su)充(chong)電(dian),電(dian)流(liu)密(mi)度(duo)過(guo)大(dai),負(fu)極(ji)嚴(yan)重(chong)極(ji)化(hua),鋰(li)的(di)沉(chen)積(ji)會(kuai)更(geng)加(jia)明(ming)顯(xian)。正(zheng)極(ji)過(guo)充(chong)導(dao)致(zhi)蓄(xu)電(dian)池(chi)容(rong)量(liang)損(sun)失(shi)主(zhu)要(yao)是(shi)由(you)於(yu)電(dian)化(hua)學(xue)惰(duo)性(xing)物(wu)質(zhi)(如(ru)Co304, Mn203等(deng))的(di)產(chan)生(sheng),破(po)壞(huai)了(liao)電(dian)極(ji)間(jian)的(di)容(rong)量(liang)平(ping)衡(heng),其(qi)容(rong)量(liang)損(sun)失(shi)是(shi)不(bu)AJ逆(ni)的(di)。LiyCoO2- (1-y) /3[Co304+02 (g) ]+yLiCo02y<0.4同(tong)時(shi)正(zheng)極(ji)材(cai)料(liao)在(zai)密(mi)封(feng)的(di)銼(cuo)離(li)子(zi)電(dian)池(chi)中(zhong)分(fen)解(xie)產(chan)生(sheng)的(di)氧(yang)氣(qi)由(you)於(yu)不(bu)存(cun)在(zai)再(zai)化(hua)合(ge)反(fan)應(ying)(如(ru)生(sheng)成(cheng)H20)與(yu)電(dian)解(xie)液(ye)分(fen)解(xie)產(chan)生(sheng)的(di)可(ke)燃(ran)性(xing)氣(qi)體(ti)同(tong)時(shi)積(ji)累(lei),後(hou)果(guo)將(qiang)不(bu)堪(kan)設(she)想(xiang)。過(guo)充(chong)還(huan)會(kuai)導(dao)致(zhi)電(dian)解(xie)液(ye)的(di)氧(yang)化(hua)反(fan)應(ying),其(qi)氧(yang)化(hua)速(su)率(shuai)跟(gen)正(zheng)極(ji)材(cai)料(liao)表(biao)而(er)積(ji)大(dai)小(xiao)、集(ji)電(dian)體(ti)材(cai)料(liao)以(yi)及(ji)所(suo)添(tian)加(jia)的(di)導(dao)電(dian)劑(ji)(炭(tan)黑(hei)等(deng))有(you)很(hen)大(dai)關(guan)係(ji),同(tong)時(shi),炭(tan)黑(hei)的(di)種(zhong)類(lei)及(ji)表(biao)麵(mian)積(ji)大(dai)小(xiao)也(ye)是(shi)影(ying)響(xiang)電(dian)解(xie)液(ye)氧(yang)化(hua)的(di)一(yi)個(ge)重(chong)要(yao)因(yin)素(su),其(qi)表(biao)而(er)積(ji)越(yue)大(dai),溶(rong)劑(ji)更(geng)容(rong)易(yi)在(zai)表(biao)麵(mian)氧(yang)化(hua)。當(dang)壓(ya)高(gao)於(yu)4.5V時(shi)電(dian)解(xie)液(ye)就(jiu)會(kuai)氧(yang)化(hua)生(sheng)成(cheng)不(bu)溶(rong)物(wu)(如(ru)Li2Co3)和(hu)氣(qi)體(ti),這(zhe)些(xie)不(bu)溶(rong)物(wu)會(kuai)堵(du)塞(se)在(zai)電(dian)極(ji)的(di)微(wei)孔(kong)裏(li)麵(mian)阻(zu)礙(ai)鋰(li)離(li)子(zi)的(di)遷(qian)移(yi)而(er)造(zao)成(cheng)循(xun)環(huan)過(guo)程(cheng)中(zhong)容(rong)量(liang)損(sun)失(shi)。

2、電(dian)解(xie)液(ye)中(zhong)常(chang)常(chang)會(kuai)含(han)有(you)氧(yang)、水(shui)和(hu)二(er)氧(yang)化(hua)碳(tan)等(deng)物(wu)質(zhi)。微(wei)量(liang)的(di)水(shui)對(dui)石(dan)墨(mo)電(dian)極(ji)性(xing)能(neng)沒(mo)影(ying)響(xiang),但(dan)水(shui)含(han)量(liang)過(guo)高(gao)會(kuai)生(sheng)成(cheng)LIOH (s)和(hu)Li20沉(chen)積(ji)層(ceng),不(bu)利(li)於(yu)鋰(li)離(li)子(zi)嵌(kan)入(ru),造(zao)成(cheng)不(bu)可(ke)逆(ni)容(rong)量(liang)損(sun)失(shi):H20+e-*OH 一(yi)+1/2H222 0H-+Li+-.LiOH (s) LiOH+Li++e-.Li2O (s) +1/2H2溶(rong)劑(ji)中(zhong)的(di)C02 在(zai)負(fu)極(ji)上(shang)能(neng)還(huan)原(yuan)生(sheng)成(cheng)CO和(hu)LiCO3(s): 2CO2+2e+2Li+-.Li2CO3+CO CO會(kuai)使(shi)電(dian)池(chi)內(nei)壓(ya)升(sheng)高(gao),而(er)Li2CO3 (s)使(shi)電(dian)池(chi)內(nei)阻(zu)增(zeng)大(dai)影(ying)響(xiang)電(dian)池(chi)性(xing)能(neng)。

3、自(zi)放(fang)電(dian)自(zi)放(fang)電(dian)是(shi)指(zhi)電(dian)池(chi)在(zai)未(wei)使(shi)用(yong)狀(zhuang)態(tai)下(xia),電(dian)容(rong)量(liang)自(zi)然(ran)損(sun)失(shi)的(di)現(xian)象(xiang)。鋰(li)離(li)子(zi)電(dian)池(chi)自(zi)放(fang)電(dian)導(dao)致(zhi)容(rong)量(liang)報(bao)失(shi)分(fen)兩(liang)種(zhong)情(qing)況(kuang):一(yi)是(shi)可(ke)逆(ni)容(rong)量(liang)損(sun)失(shi):氣(qi)是(shi)不(bu)可(ke)逆(ni)容(rong)量(liang)的(di)損(sun)失(shi)。可(ke)逆(ni)容(rong)量(liang)損(sun)失(shi)是(shi)指(zhi)損(sun)失(shi)的(di)容(rong)量(liang)能(neng)在(zai)充(chong)電(dian)時(shi)恢(hui)複(fu),而(er)不(bu)可(ke)逆(ni)容(rong)量(liang)損(sun)失(shi)則(ze)相(xiang)反(fan),如(ru)鋰(li)錳(meng)氧(yang)化(hua)物(wu)正(zheng)極(ji)與(yu)溶(rong)劑(ji)會(kuai)發(fa)生(sheng)微(wei)電(dian)池(chi)作(zuo)用(yong)產(chan)生(sheng)自(zi)放(fang)電(dian)造(zao)成(cheng)不(bu)可(ke)逆(ni)容(rong)量(liang)損(sun)失(shi)。自(zi)放(fang)電(dian)程(cheng)度(duo)受(shou)正(zheng)極(ji)材(cai)料(liao)、電(dian)池(chi)的(di)製(zhi)作(zuo)工(gong)藝(yi)、電(dian)解(xie)液(ye)的(di)性(xing)質(zhi)、溫(wen)度(duo)和(hu)時(shi)等(deng)因(yin)素(su)影(ying)響(xiang)。如(ru)自(zi)放(fang)電(dian)速(su)率(shuai)主(zhu)要(yao)因(yin)溶(rong)劑(ji)氧(yang)化(hua)速(su)率(shuai)控(kong)製(zhi),因(yin)此(ci)溶(rong)劑(ji)的(di)穩(wen)定(ding)性(xing)影(ying)響(xiang)著(zhuo)電(dian)池(chi)的(di)貯(zhu)存(cun)壽(shou)命(ming),如(ru)果(guo)負(fu)極(ji)處(chu)於(yu)充(chong)足(ju)電(dian)的(di)狀(zhuang)態(tai)而(er)正(zheng)極(ji)發(fa)生(sheng)自(zi)放(fang)電(dian),電(dian)池(chi)內(nei)容(rong)量(liang)平(ping)衡(heng)被(bei)破(po)壞(huai),將(qiang)導(dao)致(zhi)性(xing)容(rong)量(liang)損(sun)失(shi)。長(zhang)時(shi)間(jian)或(huo)經(jing)常(chang)自(zi)放(fang)電(dian)時(shi),鋰(li)有(you)可(ke)能(neng)沉(chen)積(ji)在(zai)碳(tan)上(shang),增(zeng)大(dai)兩(liang)級(ji)間(jian)容(rong)量(liang)不(bu)平(ping)衡(heng)程(cheng)度(duo)。Pistoia等(deng)認(ren)為(wei)自(zi)放(fang)電(dian)的(di)氧(yang)化(hua)產(chan)物(wu)堵(du)塞(se)電(dian)極(ji)材(cai)料(liao)上(shang)的(di)微(wei)孔(kong),使(shi)鋰(li)的(di)嵌(kan)入(ru)和(hu)脫(tuo)出(chu)困(kun)難(nan)並(bing)且(qie)使(shi)內(nei)阻(zu)增(zeng)大(dai)和(hu)放(fang)電(dian)效(xiao)率(shuai)降(xiang)低(di),從(zong)而(er)導(dao)致(zhi)不(bu)可(ke)逆(ni)容(rong)量(liang)損(sun)失(shi)。
4、電(dian)極(ji)不(bu)穩(wen)定(ding)性(xing)如(ru)上(shang)所(suo)述(shu),正(zheng)極(ji)活(huo)性(xing)物(wu)質(zhi)在(zai)充(chong)電(dian)狀(zhuang)態(tai)下(xia)會(kuai)氧(yang)化(hua)電(dian)解(xie)質(zhi)分(fen)解(xie)而(er)造(zao)成(cheng)容(rong)量(liang)損(sun)失(shi)。另(ling)外(wai),影(ying)響(xiang)正(zheng)極(ji)材(cai)料(liao)溶(rong)解(xie)的(di)因(yin)素(su)還(huan)有(you)正(zheng)極(ji)活(huo)性(xing)物(wu)質(zhi)的(di)結(jie)構(gou)缺(que)陷(xian),充(chong)電(dian)電(dian)勢(shi)過(guo)高(gao)以(yi)及(ji)正(zheng)極(ji)材(cai)料(liao)中(zhong)炭(tan)黑(hei)的(di)含(han)量(liang)。