數碼產品的用戶們發現，隨著時間的推移，鋰電池容量總會損耗掉一些。雖然剛買來時鋰電池容量的(de)(de)(de)續航表(biao)現還不錯，但經歷2年頻繁的(de)(de)(de)充(chong)放(fang)電(dian)(dian)(dian)之后，鋰電(dian)(dian)(dian)池(chi)容量就完全是兩(liang)個樣了(le)。好消息是，美國能源部的(de)(de)(de)科學(xue)家們，最近似乎搞清(qing)楚了(le)導致(zhi)電(dian)(dian)(dian)池(chi)“縮容”的(de)(de)(de)其中(zhong)一種機(ji)理，未來有望想出應對的(de)(de)(de)策(ce)略。在(zai)(zai)一顆常見的(de)(de)(de)鋰離(li)子(zi)可(ke)(ke)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)池(chi)中(zhong)，鋰離(li)子(zi)可(ke)(ke)以在(zai)(zai)陰陽兩(liang)極的(de)(de)(de)電(dian)(dian)(dian)解(jie)液(ye)中(zhong)穿行，從而產(chan)生(sheng)為設備供能的(de)(de)(de)電(dian)(dian)(dian)流(liu)。而所謂(wei)的(de)(de)(de)容量，可(ke)(ke)簡(jian)單理解(jie)成電(dian)(dian)(dian)池(chi)中(zhong)（在(zai)(zai)充(chong)放(fang)電(dian)(dian)(dian)時）來回(hui)跑的(de)(de)(de)鋰離(li)子(zi)體積(ji)。

鋰(li)電(dian)(dian)(dian)(dian)池容量隨著循(xun)環次數(shu)的(de)(de)增(zeng)加而(er)逐漸下降(jiang)，充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓平(ping)臺(tai)升高，放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓平(ping)臺(tai)明(ming)顯下降(jiang)，放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓平(ping)臺(tai)變短。由歐姆定律可知，電(dian)(dian)(dian)(dian)池在(zai)(zai)恒(heng)流(liu)(liu)(liu)充放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)時，其輸入(ru)輸出電(dian)(dian)(dian)(dian)壓與(yu)電(dian)(dian)(dian)(dian)阻(zu)、電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)存在(zai)(zai)以下關(guan)系(xi)：V=E-IR。式中，E為(wei)電(dian)(dian)(dian)(dian)池在(zai)(zai)平(ping)衡電(dian)(dian)(dian)(dian)位下的(de)(de)電(dian)(dian)(dian)(dian)動勢，I為(wei)恒(heng)流(liu)(liu)(liu)充放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)（充電(dian)(dian)(dian)(dian)時電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)為(wei)負值、放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)時電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)為(wei)正值），R是電(dian)(dian)(dian)(dian)池的(de)(de)總內(nei)阻(zu)，包(bao)括溶液內(nei)阻(zu)，正負極的(de)(de)極化內(nei)阻(zu)以及(ji)活性物質和溶液之間(jian)、活性物質與(yu)集流(liu)(liu)(liu)體之間(jian)的(de)(de)接(jie)觸(chu)電(dian)(dian)(dian)(dian)阻(zu)。電(dian)(dian)(dian)(dian)池在(zai)(zai)恒(heng)流(liu)(liu)(liu)充放(fang)(fang)(fang)(fang)制式下進行循(xun)環，充放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)保持恒(heng)定不變。而(er)隨循(xun)環次數(shu)增(zeng)加，電(dian)(dian)(dian)(dian)池的(de)(de)總內(nei)阻(zu)在(zai)(zai)不斷增(zeng)大。因此，電(dian)(dian)(dian)(dian)池循(xun)環過程(cheng)中，充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓平(ping)臺(tai)逐漸升高，而(er)放(fang)(fang)(fang)(fang)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓平(ping)臺(tai)逐漸降(jiang)低。

美國能(neng)源部的(de)這項研究發(fa)現(xian)，組(zu)成電池電極(ji)的(de)材料經常會(hui)破裂分解，使得某些(xie)金屬離子（這里(li)特(te)指錳(meng)元素(su)）可以自由(you)浮(fu)動并跑到相反的(de)電極(ji)那，然后困陷住鋰離子。

隨著時間(jian)的推移(yi)，越來越多的鋰離子不能投入正常工作(zuo)（被(bei)鎖住(zhu)），鋰電池的容量(liang)也(ye)因此而逐漸降低，最終導致無法繼續提供(gong)理想(xiang)的續航(hang)時間(jian)。

研究(jiu) 解(jie)釋到：鋰電池(chi)(chi)容(rong)量變小是(shi)與(yu)電極上錳元(yuan)素的(de)(de)(de)管理 、以及被困(kun)住的(de)(de)(de)鋰離子(zi)數量有(you)著嚴(yan)格(ge)的(de)(de)(de)相(xiang)關性。未來在延長鋰電池(chi)(chi)使(shi)用壽命的(de)(de)(de)方法上，這個(ge)技術難(nan)關是(shi)要(yao)克(ke)服才有(you)可能的(de)(de)(de)。