一、鋰離子電池的容量特性

容量測試得到鋰離子電池在不同倍率下的放電電壓與容量關系，在整個放電過程中鋰離子電池的電壓可以分為3個階段：

1）鋰離子電(dian)池在初始階(jie)段端(duan)電(dian)壓快(kuai)(kuai)速(su)下降，放電(dian)倍率越(yue)(yue)大，電(dian)壓下降的越(yue)(yue)快(kuai)(kuai)；

2）電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)壓(ya)進入一個(ge)緩(huan)慢(man)變化的(de)階段(duan)，這段(duan)時(shi)間稱為電(dian)(dian)(dian)(dian)池(chi)的(de)平(ping)臺區，放電(dian)(dian)(dian)(dian)倍率越(yue)小(xiao)，平(ping)臺區持續(xu)的(de)時(shi)間越(yue)長，平(ping)臺電(dian)(dian)(dian)(dian)壓(ya)越(yue)高，電(dian)(dian)(dian)(dian)壓(ya)下降越(yue)緩(huan)慢(man)。在(zai)鋰(li)離子電(dian)(dian)(dian)(dian)池(chi)的(de)實際(ji)使(shi)用過(guo)程中，盡可能希(xi)望電(dian)(dian)(dian)(dian)池(chi)工作在(zai)平(ping)臺區；

3）在電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)量接近放完(wan)時(shi)，電(dian)(dian)(dian)池(chi)(chi)負(fu)載電(dian)(dian)(dian)壓(ya)開始急(ji)劇下降直(zhi)至(zhi)達到放電(dian)(dian)(dian)截止電(dian)(dian)(dian)壓(ya)。

鋰離子電(dian)(dian)(dian)(dian)池(chi)放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流的(de)大(da)小，會直接影響到電(dian)(dian)(dian)(dian)池(chi)的(de)實際容量。放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流越(yue)大(da)，電(dian)(dian)(dian)(dian)池(chi)容量相應(ying)減(jian)小，這表明(ming)放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流越(yue)大(da)，到達終止電(dian)(dian)(dian)(dian)壓經歷的(de)時間越(yue)短。所以談到電(dian)(dian)(dian)(dian)池(chi)容量時，應(ying)指明(ming)其放(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流（放(fang)電(dian)(dian)(dian)(dian)倍(bei)率）。

二、鋰(li)離(li)子電池開路電壓(ya)特性

鋰(li)離(li)子電(dian)池(chi)開路電(dian)壓(ya)與(yu)電(dian)池(chi)SOC的關系，電(dian)池(chi)的OCV-SOC曲線(xian)與(yu)電(dian)池(chi)放電(dian)電(dian)壓(ya)曲線(xian)趨(qu)勢基本相同。

在(zai)SOC的中間(jian)(jian)(jian)區間(jian)(jian)(jian)（20%<SOC<80%）內(nei)，電池的OCV變(bian)化(hua)極(ji)小，電池處于(yu)平(ping)臺(tai)區；而(er)在(zai)SOC的兩端(duan)區間(jian)(jian)(jian)（SOC<10%和SOC>90%），OCV的變(bian)化(hua)率較(jiao)大，整(zheng)個磷酸鐵鋰電池的OCV-SOC曲(qu)線呈現中間(jian)(jian)(jian)區域平(ping)坦，頭尾兩端(duan)陡(dou)峭的樣子，開路電壓法即(ji)是(shi)利(li)用這一穩定的對應關系進行SOC估計。

鋰離(li)子電池OCV-SOC關系(xi)曲(qu)線受溫度、放(fang)電倍(bei)率、老化程度因素影響較(jiao)小，但在(zai)充放(fang)電2種狀態下，兩條特(te)性曲(qu)線之間會存(cun)在(zai)一定差異。

三、鋰離(li)子電池內(nei)阻(zu)特性

鋰(li)(li)離(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)在充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)和放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時的(de)(de)(de)(de)歐姆內(nei)(nei)阻特點：在較(jiao)寬廣(guang)的(de)(de)(de)(de)SOC圍內(nei)(nei)，即SOC=[10%，100%]的(de)(de)(de)(de)區間內(nei)(nei)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)歐姆內(nei)(nei)阻變化很(hen)小，而在較(jiao)低(di)的(de)(de)(de)(de)sOC區間內(nei)(nei)，隨(sui)SOC的(de)(de)(de)(de)降低(di)歐姆內(nei)(nei)阻出(chu)現較(jiao)大幅度的(de)(de)(de)(de)增長，這是(shi)因(yin)為電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)末期，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)內(nei)(nei)部化學物質活性(xing)降低(di)；在整個SOC范圍內(nei)(nei)，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)歐姆內(nei)(nei)阻總體大于放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)歐姆內(nei)(nei)阻，這是(shi)因(yin)為鋰(li)(li)離(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)屬于自(zi)發反應，較(jiao)容易；充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)是(shi)由外部電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源作(zuo)用(yong)，使鋰(li)(li)離(li)子嵌入(ru)負極，較(jiao)困難。需要說明的(de)(de)(de)(de)是(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)內(nei)(nei)阻變化非常復(fu)雜，受溫(wen)度、放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)深(shen)度、充(chong)放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)倍率(lv)、循(xun)環(huan)次數(shu)等因(yin)素影(ying)響(xiang)。同一(yi)類(lei)型的(de)(de)(de)(de)不(bu)(bu)同電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)單體，還(huan)與(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)出(chu)廠不(bu)(bu)一(yi)致性(xing)和工作(zuo)環(huan)境(jing)的(de)(de)(de)(de)不(bu)(bu)同相(xiang)關。