如何延長金屬空氣電池的使用壽命
金(jin)屬空氣電池是最輕的(de)(de)電池類型之一,但它(ta)(ta)們可能有(you)一個主要限(xian)制:當不使用時,它(ta)(ta)們會迅速降(jiang)解,因為腐(fu)蝕會侵(qin)蝕其金(jin)屬電極。現在(zai),麻省理工學院的(de)(de)研究人員已經找到了(le)一種(zhong)大幅減(jian)少腐(fu)蝕的(de)(de)方法,使這種(zhong)電池的(de)(de)保(bao)質期更長(chang)。
雖然典型的可充電鋰離子電池在(zai)儲存一個月后僅損失約5%的電(dian)量(liang)(liang)(liang),但對(dui)于許多應用(yong)(yong)而(er)言(yan),它(ta)們(men)太昂貴,重量(liang)(liang)(liang)太重。初級(不可充電(dian))鋁(lv)(lv)空(kong)氣電(dian)池更(geng)便宜,重量(liang)(liang)(liang)更(geng)輕,但每(mei)個月可能(neng)會損失80%的電(dian)量(liang)(liang)(liang)。MIT設計通過在(zai)鋁(lv)(lv)電(dian)極和電(dian)解質之(zhi)(zhi)間(jian)引入油(you)(you)屏障來克服鋁(lv)(lv)空(kong)氣電(dian)池中的腐蝕問題(ti),兩個電(dian)池電(dian)極之(zhi)(zhi)間(jian)的流體(ti)在(zai)電(dian)池待機時(shi)吸收掉鋁(lv)(lv)。 一旦(dan)使(shi)用(yong)(yong)電(dian)池,油(you)(you)就(jiu)會快速抽出并用(yong)(yong)電(dian)解液代替。結果,能(neng)量(liang)(liang)(liang)損失每(mei)月減少(shao)到(dao)0.02%,超過千(qian)倍(bei)的改善(shan)。
雖然已(yi)經(jing)使(shi)(shi)用了(le)其他(ta)幾種(zhong)方(fang)(fang)(fang)法來延(yan)長金屬空氣電(dian)(dian)池(chi)的(de)保質(zhi)(zhi)期,但(dan)這(zhe)(zhe)些(xie)方(fang)(fang)(fang)法可能(neng)會犧(xi)牲性能(neng),大(da)多數其他(ta)方(fang)(fang)(fang)法涉及應用不同(tong)的(de),腐蝕(shi)性較(jiao)小的(de)化學配方(fang)(fang)(fang)替換(huan)電(dian)(dian)解質(zhi)(zhi),但(dan)這(zhe)(zhe)些(xie)替代方(fang)(fang)(fang)案(an)大(da)大(da)降低了(le)電(dian)(dian)池(chi)功(gong)率。其他(ta)方(fang)(fang)(fang)法包(bao)括在(zai)儲存期間(jian)將(jiang)液(ye)體電(dian)(dian)解質(zhi)(zhi)泵出并(bing)在(zai)使(shi)(shi)用前將(jiang)其泵回。這(zhe)(zhe)些(xie)方(fang)(fang)(fang)法仍然能(neng)夠顯著(zhu)腐蝕(shi)并(bing)且(qie)可能(neng)堵(du)塞(sai)電(dian)(dian)池(chi)組(zu)中的(de)管道系統。因為即(ji)使(shi)(shi)在(zai)電(dian)(dian)解質(zhi)(zhi)從電(dian)(dian)池(chi)組(zu)中排出之后,鋁(lv)也是吸(xi)水的(de),剩余(yu)的(de)電(dian)(dian)解質(zhi)(zhi)將(jiang)粘附在(zai)鋁(lv)電(dian)(dian)極表面上。電(dian)(dian)池(chi)具有(you)復(fu)雜的(de)結構,因此電(dian)(dian)解液(ye)容易被吸(xi)住,這(zhe)(zhe)導致持(chi)續的(de)腐蝕(shi)。
新電(dian)(dian)(dian)(dian)池(chi)系統(tong)的(de)(de)關鍵是(shi)放置在(zai)電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)極之間(jian)的(de)(de)保(bao)護(hu)。當使(shi)用(yong)(yong)電(dian)(dian)(dian)(dian)池(chi)時(shi)(shi),保(bao)護(hu)板的(de)(de)兩側都充滿了液體電(dian)(dian)(dian)(dian)解(jie)質,但是(shi)當電(dian)(dian)(dian)(dian)池(chi)處于待機狀態時(shi)(shi),油(you)(you)被(bei)泵(beng)(beng)入最靠近鋁(lv)(lv)電(dian)(dian)(dian)(dian)極的(de)(de)一側,從而(er)保(bao)護(hu)鋁(lv)(lv)表面(mian)免受電(dian)(dian)(dian)(dian)解(jie)液的(de)(de)影響(xiang)。新電(dian)(dian)(dian)(dian)池(chi)系統(tong)還(huan)利(li)用(yong)(yong)了鋁(lv)(lv)的(de)(de)特(te)性(xing)(xing)(xing),稱為“水(shui)下疏油(you)(you)性(xing)(xing)(xing)” – 也就是(shi)說(shuo)(shuo),當鋁(lv)(lv)浸入水(shui)中時(shi)(shi),它會從表面(mian)排斥油(you)(you)。結(jie)果,當電(dian)(dian)(dian)(dian)池(chi)重新激(ji)活并(bing)且(qie)電(dian)(dian)(dian)(dian)解(jie)質被(bei)泵(beng)(beng)回(hui)時(shi)(shi),電(dian)(dian)(dian)(dian)解(jie)質容(rong)易從鋁(lv)(lv)表面(mian)置換油(you)(you),這(zhe)恢復了電(dian)(dian)(dian)(dian)池(chi)的(de)(de)電(dian)(dian)(dian)(dian)力的(de)(de)能力。具(ju)有諷刺意味的(de)(de)是(shi),麻省(sheng)理工學(xue)院的(de)(de)腐蝕(shi)抑制方法利(li)用(yong)(yong)了鋁(lv)(lv)的(de)(de)相(xiang)同特(te)性(xing)(xing)(xing),促進了傳統(tong)系統(tong)的(de)(de)腐蝕(shi)。結(jie)果是(shi)鋁(lv)(lv)空氣(qi)原型具(ju)有比傳統(tong)鋁(lv)(lv)空氣(qi)電(dian)(dian)(dian)(dian)池(chi)更長的(de)(de)保(bao)質期。研究(jiu)人員(yuan)表示(shi),當電(dian)(dian)(dian)(dian)池(chi)重復使(shi)用(yong)(yong)然后(hou)待機一到兩天時(shi)(shi),麻省(sheng)理工學(xue)院的(de)(de)設計持續(xu)了24天,而(er)傳統(tong)的(de)(de)設計只持續(xu)了三天。研究(jiu)人員(yuan)報(bao)告說(shuo)(shuo),即(ji)使(shi)在(zai)按比例放大的(de)(de)原鋁(lv)(lv)空氣(qi)電(dian)(dian)(dian)(dian)池(chi)組中包含油(you)(you)和泵(beng)(beng)系統(tong),它們仍(reng)然比電(dian)(dian)(dian)(dian)動汽車的(de)(de)可充電(dian)(dian)(dian)(dian)鋰離子電(dian)(dian)(dian)(dian)池(chi)組重量輕5倍。
除了非常便宜之外,鋁是(shi)我們所知道(dao)的最高化學(xue)能量(liang)密(mi)度儲存材料之一(yi),也(ye)就是(shi)說(shuo),它(ta)能夠儲存和(he)輸送比每個其(qi)他任(ren)何東(dong)西(xi)更多(duo)的能量(liang),只有(you)溴,這(zhe)是(shi)昂貴和(he)危險(xian)的,具有(you)可比性。許多(duo)專家都(dou)認為鋁空(kong)(kong)氣電(dian)池(chi)可能是(shi)鋰(li)離子電(dian)池(chi)和(he)汽車汽油(you)的唯一(yi)可行替代品。鋁空(kong)(kong)氣電(dian)池(chi)已被(bei)用(yong)(yong)作(zuo)電(dian)動車輛的增程器(qi),以補(bu)充內(nei)置可充電(dian)電(dian)池(chi),以在內(nei)置電(dian)池(chi)耗盡時(shi)增加許多(duo)額外的行駛里(li)程。它(ta)們有(you)時(shi)也(ye)用(yong)(yong)作(zuo)偏遠地區或某些(xie)水下航(hang)行器(qi)的電(dian)源(yuan)。但是(shi),雖然(ran)這(zhe)些(xie)電(dian)池(chi)可以長時(shi)間(jian)存放,只要它(ta)們未被(bei)使用(yong)(yong),一(yi)旦(dan)它(ta)們第一(yi)次打開(kai),它(ta)們就會開(kai)始迅速(su)降(jiang)解。






