什么是太陽能高能電池?
新(xin)能源的開發是始終備受關(guan)注的話(hua)題(ti),最近(jin)出現(xian)了(le)一種叫(jiao)高(gao)能電池(chi)的新(xin)能源電池(chi),那高(gao)能電池(chi)是什么呢?
高能電池是指具有較高比能量的電池。比較耐用和供電量高電池比能量,在電池反應中,1千克反應物質所產生的電能稱為電池的理論比能量。


據(ju)在國(guo)際頂級(ji)期刊《科學(xue)》(Science)雜志上報道,來自中國(guo)南開大(da)學(xue)的電(dian)(dian)池研究(jiu)團隊在太陽能(neng)電(dian)(dian)池這一(yi)領域有(you)(you)了最新的研究(jiu)進展——他們制備了一(yi)種基于有(you)(you)機半(ban)導(dao)體材料的太陽能(neng)電(dian)(dian)池,其(qi)能(neng)量轉化效率(把光能(neng)轉化成(cheng)電(dian)(dian)能(neng)的效率)達到了17.3%,放(fang)置166天(tian)后性能(neng)僅有(you)(you)輕(qing)微衰減(約4%)。
17.3%是什么概念?可以說,它(ta)超越(yue)了(le)目前同類有(you)機太(tai)陽能電(dian)池效率14%的(de)最高值,創下了(le)新的(de)世界紀錄——在提高能源轉化率方(fang)面,每個百分點的(de)進步都極其不易(yi)。
太(tai)(tai)(tai)陽(yang)能(neng)(neng)(neng)電(dian)池這個概念,或許大家都不(bu)陌(mo)生(sheng)。但(dan)(dan)具體(ti)(ti)說到制造太(tai)(tai)(tai)陽(yang)能(neng)(neng)(neng)電(dian)池的(de)(de)(de)材(cai)料(liao)(liao),可(ke)能(neng)(neng)(neng)了解(jie)的(de)(de)(de)人就(jiu)不(bu)多了。目前,已經商品化的(de)(de)(de)太(tai)(tai)(tai)陽(yang)能(neng)(neng)(neng)電(dian)池板大多由無機半導(dao)體(ti)(ti)材(cai)料(liao)(liao)制造,它具有原材(cai)料(liao)(liao)易獲取(比如(ru)硅)、吸收光譜寬、能(neng)(neng)(neng)量轉(zhuan)化效(xiao)率高等優勢。但(dan)(dan)事實上,無機半導(dao)體(ti)(ti)材(cai)料(liao)(liao)并不(bu)是將太(tai)(tai)(tai)陽(yang)能(neng)(neng)(neng)轉(zhuan)化為電(dian)能(neng)(neng)(neng)的(de)(de)(de)完美解(jie)決(jue)方(fang)案(an),原因在于——它們太(tai)(tai)(tai)脆了,科學(xue)家們必須不(bu)斷(duan)去開發和尋(xun)找可(ke)替(ti)代的(de)(de)(de)解(jie)決(jue)方(fang)案(an)。
有(you)機(ji)(ji)(ji)太(tai)陽能(neng)(neng)電(dian)池(chi)(chi)一(yi)(yi)直是近年(nian)來(lai)學術(shu)界(jie)和(he)(he)工(gong)業界(jie)的研究熱點。此(ci)外,科學家們經(jing)(jing)過分析(xi)后普遍認(ren)為(wei),如果繼續優化(hua)(hua)電(dian)池(chi)(chi)器(qi)件構(gou)型和(he)(he)材料選擇,有(you)機(ji)(ji)(ji)太(tai)陽能(neng)(neng)電(dian)池(chi)(chi)的能(neng)(neng)量轉化(hua)(hua)效率理論(lun)上可以突破25%。尤其在過去(qu)的十年(nian)間,有(you)機(ji)(ji)(ji)太(tai)陽能(neng)(neng)電(dian)池(chi)(chi)更是經(jing)(jing)歷(li)了躍遷式的發展(zhan),其性能(neng)(neng)已經(jing)(jing)可以與商品化(hua)(hua)的無(wu)機(ji)(ji)(ji)硅電(dian)池(chi)(chi)媲美,像高處(chu)的王冠一(yi)(yi)樣鼓舞(wu)著科學家們不斷地接近它。
不(bu)過,我們距離真正的有機太陽能電池(chi)的商(shang)品化還有一(yi)段距離,仍(reng)有一(yi)些問(wen)題需(xu)要克服——比如,很多有機材(cai)料(liao)在太陽光的照射下并不(bu)那么穩(wen)定、制作過程中使用的溶劑(ji)毒性(xing)較大(da)(da),以及大(da)(da)規(gui)模生產工藝尚未成熟。
高(gao)能電池應(ying)用主要有:遙感勘測、航天航空、海洋勘探、地(di)質調研(yan)
高能電池(chi)的種類
1、以鎂作(zuo)負極活性物質的鎂干高能電(dian)池
其結(jie)構與鋅-錳干(gan)電(dian)(dian)池(chi)基本相同。鎂(mei)(mei)的(de)標準電(dian)(dian)極(ji)電(dian)(dian)勢比(bi)較低,電(dian)(dian)化(hua)學當量(liang)小,具(ju)備了作(zuo)為高(gao)(gao)能電(dian)(dian)池(chi)負極(ji)活(huo)性(xing)物質的(de)優良條件。例如鎂(mei)(mei)-錳干(gan)電(dian)(dian)池(chi)的(de)實際比(bi)能量(liang)是(shi)鋅-錳干(gan)電(dian)(dian)池(chi)的(de)4倍,工(gong)作(zuo)時電(dian)(dian)壓平穩,在低溫下也具(ju)有較好的(de)工(gong)作(zuo)能力,并且能耐高(gao)(gao)溫貯存。其缺點是(shi)有電(dian)(dian)壓滯后(hou)現象(接通后(hou)需要經一段時間(jian),電(dian)(dian)壓才能上升至終止電(dian)(dian)壓值),滯后(hou)時間(jian)約為2~3秒;由于(yu)腐蝕作(zuo)用,鎂(mei)(mei)電(dian)(dian)極(ji)電(dian)(dian)流效率低;不宜于(yu)小電(dian)(dian)流長(chang)時間(jian)的(de)間(jian)歇放電(dian)(dian)。
2、金屬-空(kong)氣高能(neng)電池
以(yi)空氣(qi)中的氧氣(qi)作為(wei)正(zheng)極(ji)活(huo)性(xing)物(wu)質(zhi),金(jin)屬(shu)作為(wei)負(fu)極(ji)活(huo)性(xing)物(wu)質(zhi)的電池。
3、鋰(li)-非水電(dian)解質(zhi)溶(rong)液高能電(dian)池
鋰的(de)電(dian)(dian)(dian)(dian)化學當量(liang)(liang)約為(wei)鎂的(de)二分之一,因此(ci)作為(wei)高(gao)能電(dian)(dian)(dian)(dian)池(chi)的(de)負極(ji),鋰比(bi)(bi)鎂更優(you)越(yue)。但(dan)鋰與水要(yao)激烈反應,須(xu)采用有機(ji)溶(rong)劑或非水的(de)無機(ji)溶(rong)劑來配制(zhi)電(dian)(dian)(dian)(dian)解(jie)質(zhi)(zhi)溶(rong)液(ye),再(zai)加入無機(ji)鹽使之導電(dian)(dian)(dian)(dian)。使用的(de)正極(ji)材料主要(yao)有固體(ti)氟化物(wu)、氯(lv)化物(wu)、氧化物(wu)、硫化物(wu)。這些電(dian)(dian)(dian)(dian)池(chi)的(de)理論比(bi)(bi)能量(liang)(liang)大都在1000瓦時(shi)/千克以(yi)上。其實際比(bi)(bi)能量(liang)(liang)也比(bi)(bi)較高(gao)。例(li)如(ru)鋰-氟化銅(Li/CuF2)電(dian)(dian)(dian)(dian)池(chi)在放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流密度為(wei)2毫安(an)/厘米2時(shi),實際比(bi)(bi)能量(liang)(liang)可達(da)250瓦時(shi)/千克。由(you)于有機(ji)電(dian)(dian)(dian)(dian)解(jie)質(zhi)(zhi)溶(rong)液(ye)的(de)比(bi)(bi)電(dian)(dian)(dian)(dian)導小,電(dian)(dian)(dian)(dian)流密度不(bu)能提高(gao),因此(ci)鋰-非水電(dian)(dian)(dian)(dian)解(jie)質(zhi)(zhi)溶(rong)液(ye)電(dian)(dian)(dian)(dian)池(chi)是(shi)一種高(gao)比(bi)(bi)能量(liang)(liang)、低(di)功率的(de)電(dian)(dian)(dian)(dian)池(chi)。而鋰-硫化物(wu)電(dian)(dian)(dian)(dian)池(chi)在重負荷下(xia)放電(dian)(dian)(dian)(dian),特別(bie)當外部短路時(shi)還會發生(sheng)爆炸。
4、鈉-硫高能電(dian)池(chi)
是近幾(ji)年(nian)研制出的(de)(de)比較成熟的(de)(de)一種二次(ci)高能電(dian)(dian)(dian)池。它的(de)(de)負極(ji)(ji)是熔(rong)融(rong)金屬鈉(Na);正(zheng)極(ji)(ji)活性(xing)物質(zhi)是熔(rong)融(rong)多(duo)硫化(hua)鈉(Na2Sx),通常充(chong)滿在多(duo)孔碳(tan)中(zhong),碳(tan)作(zuo)為(wei)正(zheng)極(ji)(ji)集流體。需采用導電(dian)(dian)(dian)陶瓷(ci)管將鈉與多(duo)硫化(hua)鈉隔(ge)開,以防直接反應(ying)而引起自(zi)放電(dian)(dian)(dian)。此外,陶瓷(ci)管還(huan)起電(dian)(dian)(dian)池中(zhong)的(de)(de)電(dian)(dian)(dian)解(jie)質(zhi)作(zuo)用。電(dian)(dian)(dian)池放電(dian)(dian)(dian)時,負極(ji)(ji)上的(de)(de)反應(ying)為(wei)2Na─→2Na++2e-Na+
通過導電(dian)(dian)陶(tao)瓷管進入正極與硫發生反應形成多硫化物。當負(fu)極的(de)鈉耗(hao)盡(jin)的(de)時候則放(fang)(fang)電(dian)(dian)終止。為使鈉和多硫化鈉都處于(yu)液態,放(fang)(fang)電(dian)(dian)需(xu)在300℃左(zuo)右進行。鈉-硫電(dian)(dian)池的(de)實際(ji)比能(neng)量已經達100瓦時/千(qian)克,充(chong)放(fang)(fang)電(dian)(dian)循(xun)環(huan)壽命(ming)可達2000個深放(fang)(fang)電(dian)(dian)循(xun)環(huan),因此(ci)特別適于(yu)用作車輛的(de)電(dian)(dian)力電(dian)(dian)池。
5、鋰(li)高(gao)溫高(gao)能電(dian)(dian)(dian)(dian)池(chi):以(yi)(yi)(yi)鋰(li)為(wei)(wei)(wei)負極(ji)(ji),硫族(包括硫化物)和(he)氯(lv)氣為(wei)(wei)(wei)正極(ji)(ji)活(huo)性物質,熔融(rong)鹽為(wei)(wei)(wei)電(dian)(dian)(dian)(dian)解質的電(dian)(dian)(dian)(dian)池(chi)。由于采用(yong)熔融(rong)鹽,電(dian)(dian)(dian)(dian)池(chi)在300~600℃間(jian)工作,因此鋰(li)高(gao)溫高(gao)能電(dian)(dian)(dian)(dian)池(chi)與鈉-硫電(dian)(dian)(dian)(dian)池(chi)合(he)(he)稱為(wei)(wei)(wei)高(gao)溫電(dian)(dian)(dian)(dian)池(chi)。液態鋰(li)電(dian)(dian)(dian)(dian)極(ji)(ji)經多次充(chong)放電(dian)(dian)(dian)(dian)循環后易失去(qu)濕潤性;硫在高(gao)溫下要揮(hui)發,并(bing)有腐蝕性;氯(lv)是氣體,難以(yi)(yi)(yi)處(chu)理。因此鋰(li)高(gao)溫電(dian)(dian)(dian)(dian)池(chi)研制的方向將向以(yi)(yi)(yi)鋰(li)合(he)(he)金為(wei)(wei)(wei)負極(ji)(ji)和(he)以(yi)(yi)(yi)硫化物為(wei)(wei)(wei)正極(ji)(ji)的方向發展。如(ru)鋰(li)鋁合(he)(he)金-硫化鐵電(dian)(dian)(dian)(dian)池(chi),其電(dian)(dian)(dian)(dian)池(chi)反應為(wei)(wei)(wei)4LiAl+FeS2─→2Li2S+Fe+4Al。





