活性(xing)炭的電化(hua)學性(xing)能

　　能(neng)源(yuan)(yuan)(yuan)問題是21世紀(ji)活性(xing)炭電化(hua)學性(xing)能(neng)*顯著(zhu)的(de)全球挑戰之一。全球對(dui)能(neng)源(yuan)(yuan)(yuan)供應和(he)環(huan)境保護的(de)需(xu)求(qiu)急劇(ju)增(zeng)加，迫使世界(jie)面(mian)臨經濟危機。據*近報道，全球能(neng)耗每年(nian)約為4.1×10 20 J--其(qi)80%來自不(bu)可再(zai)生碳密集型化(hua)石燃(ran)(ran)料，包括煤(mei)、石油(you)和(he)天(tian)然(ran)氣。過(guo)度依賴燃(ran)(ran)燒化(hua)石燃(ran)(ran)料帶來了(le)許多(duo)環(huan)境問題，增(zeng)加了(le)全球經濟的(de)負擔。隨著(zhu)世界(jie)的(de)不(bu)斷發展，能(neng)源(yuan)(yuan)(yuan)需(xu)求(qiu)迅速(su)增(zeng)長，地球不(bu)可再(zai)生能(neng)源(yuan)(yuan)(yuan)總量相當有限。因此(ci)，為了(le)滿足日益增(zeng)長的(de)能(neng)源(yuan)(yuan)(yuan)需(xu)求(qiu)，減(jian)少對(dui)環(huan)境的(de)應力，需(xu)要安(an)全、實用、可持續、性(xing)能(neng)良(liang)好的(de)能(neng)量轉換和(he)存儲設備。

　　電(dian)(dian)(dian)化(hua)(hua)學(xue)電(dian)(dian)(dian)容(rong)器(qi)*近引起了(le)人們的(de)極(ji)(ji)大興趣，包括顯(xian)著的(de)循環效(xiao)率、預期的(de)循環壽命、快速(su)充放電(dian)(dian)(dian)率和(he)(he)優良的(de)功(gong)率密度，以及便攜式(shi)電(dian)(dian)(dian)子(zi)、混(hun)合電(dian)(dian)(dian)動汽車和(he)(he)存(cun)儲器(qi)的(de)備用設備。毫無疑問，活性(xing)炭(tan)雙(shuang)層電(dian)(dian)(dian)容(rong)器(qi)的(de)性(xing)能主要取(qu)決于其電(dian)(dian)(dian)極(ji)(ji)材料的(de)類型(xing)和(he)(he)形式(shi)。超級電(dian)(dian)(dian)容(rong)器(qi)的(de)紋理(li)電(dian)(dian)(dian)位(wei)電(dian)(dian)(dian)極(ji)(ji)材料研究以各(ge)種形式(shi)進行了(le)報道(dao)。以活性(xing)炭(tan)為材料，如活性(xing)炭(tan)、石墨(mo)烯、碳納米結(jie)構，如管(guan)道(dao)和(he)(he)纖維(wei)、來自碳化(hua)(hua)物的(de)碳等。

　　此(ci)外(wai)，活(huo)性(xing)炭具有多(duo)孔結構豐(feng)富、雜原子自(zi)摻雜、物理化(hua)學穩(wen)定性(xing)和環(huan)保等優點，廣(guang)(guang)泛(fan)應(ying)用于能源相關領域(yu)，以滿足能源供應(ying)的迫切需求。截至(zhi)目前，堅果殼、椰殼、木材、動物骨、纖(xian)維等各種活(huo)性(xing)炭材料已被(bei)廣(guang)(guang)泛(fan)用作(zuo)制(zhi)造電容器的前體。大(da)多(duo)數報(bao)告稱，活(huo)性(xing)炭的儲能性(xing)能超(chao)過了其他非活(huo)性(xing)炭材料的儲能性(xing)能。

　　活性炭的電化學性能

　　5%的(de)電(dian)(dian)極(ji)PTFE，乙炔碳黑(hei)10%，活(huo)性(xing)(xing)炭85%。將所(suo)有材料均(jun)勻混合，然(ran)后(hou)在(zai)1.4MPa將其壓(ya)(ya)在(zai)鎳(nie)泡沫基(ji)材上(shang)，然(ran)后(hou)在(zai)真空烘箱中壓(ya)(ya)在(zai)110℃干燥12小時。每個集電(dian)(dian)器上(shang)的(de)活(huo)性(xing)(xing)物質(zhi)(zhi)量(liang)約為4.7mg·cm -2。6.通過多孔膜分離M KOH對稱雙電(dian)(dian)極(ji)電(dian)(dian)池組裝電(dian)(dian)解質(zhi)(zhi)水溶液。采(cai)用循環伏(fu)安法(CV)，恒(heng)電(dian)(dian)流充放電(dian)(dian)(GCD)電(dian)(dian)化學(xue)阻抗光(guang)(guang)譜(EIS)研究樣(yang)品的(de)電(dian)(dian)容(rong)性(xing)(xing)能。在(zai)0.01Hz-100KHz在(zai)5的(de)頻(pin)率范圍(wei)內mV在(zai)開路電(dian)(dian)位下(xia)測量(liang)范圍(wei)EIS光(guang)(guang)譜。所(suo)有電(dian)(dian)化學(xue)測量(liang)均(jun)在(zai)電(dian)(dian)化學(xue)工(gong)作(zuo)站進行(xing)。所(suo)有試驗(yan)均(jun)在(zai)室溫下(xia)進行(xing)。

　　活(huo)性炭的(de)形狀和(he)結構(gou)

　　四個活性炭樣品(pin)(pin)(LSC-1-4)的(de)(de)(de)XRD圖譜顯(xian)示沒(mei)有尖銳(rui)(rui)和(he)(he)強峰(feng)(feng)(如圖1所(suo)示)，表(biao)示所(suo)有活性炭樣品(pin)(pin)的(de)(de)(de)非晶狀態。一方面位(wei)于23左右°位(wei)于44的(de)(de)(de)寬(kuan)峰(feng)(feng)和(he)(he)寬(kuan)峰(feng)(feng)°弱(ruo)(ruo)峰(feng)(feng)是(shi)無定形石墨碳的(de)(de)(de)特征峰(feng)(feng)，表(biao)明(ming)(ming)LSC樣品(pin)(pin)的(de)(de)(de)石墨化程(cheng)度(du)有限(xian)。另一方面，以44°中心(xin)弱(ruo)(ruo)峰(feng)(feng)的(de)(de)(de)出現表(biao)明(ming)(ming)電導率的(de)(de)(de)提高(gao)。特別地(di)，LSC-1在(zai)44°與其他樣品(pin)(pin)相比(bi)，觀(guan)察到(dao)的(de)(de)(de)尖銳(rui)(rui)峰(feng)(feng)值表(biao)明(ming)(ming)，LSC-石墨化程(cheng)度(du)提高(gao)。

　　電化學表征活性炭

　　基于活(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)的(de)(de)(de)(de)超級(ji)電(dian)(dian)(dian)(dian)(dian)容器(qi)的(de)(de)(de)(de)活(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)樣品(SC-LSC)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)容性(xing)(xing)，LSC-3和(he)(he)(he)LSC-4通(tong)過電(dian)(dian)(dian)(dian)(dian)化學技術序(xu)列進行評估(gu)，包括室溫下(xia)CV，GCD和(he)(he)(he)EIS測試(shi)。圖2顯示(shi)了(le)四個不(bu)同掃描(miao)速(su)率的(de)(de)(de)(de)人SC-LSC的(de)(de)(de)(de)CV電(dian)(dian)(dian)(dian)(dian)勢窗的(de)(de)(de)(de)范圍為0-0.8V。如所見，所有(you)超級(ji)電(dian)(dian)(dian)(dian)(dian)容活(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)在(zai)相對(dui)較(jiao)低的(de)(de)(de)(de)掃描(miao)速(su)率下(xia)具(ju)有(you)理想的(de)(de)(de)(de)矩(ju)形(xing)電(dian)(dian)(dian)(dian)(dian)容性(xing)(xing)能(neng)，即(ji)充(chong)電(dian)(dian)(dian)(dian)(dian) - 雙層(ceng)電(dian)(dian)(dian)(dian)(dian)容器(qi)在(zai)放電(dian)(dian)(dian)(dian)(dian)過程中的(de)(de)(de)(de)典型性(xing)(xing)質(zhi)。即(ji)使(shi)在(zai)500 mV·s -在(zai)1的(de)(de)(de)(de)高(gao)掃描(miao)速(su)率下(xia)，如圖2所示(shi)d，SC-LSCs的(de)(de)(de)(de)CV由于樣品的(de)(de)(de)(de)優良導(dao)電(dian)(dian)(dian)(dian)(dian)性(xing)(xing)和(he)(he)(he)低質(zhi)量傳(chuan)輸電(dian)(dian)(dian)(dian)(dian)阻，曲線(xian)保持(chi)了(le)伏安曲線(xian)的(de)(de)(de)(de)準矩(ju)形(xing)狀，幾乎沒(mei)有(you)變形(xing)。顯然，短離(li)子通(tong)道和(he)(he)(he)電(dian)(dian)(dian)(dian)(dian)解(jie)質(zhi)儲(chu)層(ceng)的(de)(de)(de)(de)快速(su)離(li)子運輸來自(zi)活(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)樣品的(de)(de)(de)(de)分層(ceng)孔結構(gou)。類似(si)地，超級(ji)電(dian)(dian)(dian)(dian)(dian)容活(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)由于理想的(de)(de)(de)(de)分層(ceng)多孔結構(gou)和(he)(he)(he)活(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)的(de)(de)(de)(de)高(gao)表面積而(er)顯示(shi)出(chu)*高(gao)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)容值。

　　碳化(hua)活(huo)(huo)(huo)化(hua)前，由纖維(wei)材料合成四(si)種活(huo)(huo)(huo)性(xing)(xing)炭。所有(you)(you)制(zhi)備(bei)的(de)(de)(de)活(huo)(huo)(huo)性(xing)(xing)炭主要表(biao)(biao)現(xian)(xian)為微孔(kong)結構。發(fa)現(xian)(xian)通過ZnCl 2活(huo)(huo)(huo)化(hua)法制(zhi)備(bei)的(de)(de)(de)活(huo)(huo)(huo)性(xing)(xing)炭表(biao)(biao)現(xian)(xian)出(chu)(chu)*大(da)的(de)(de)(de)比表(biao)(biao)面(mian)積，在所有(you)(you)活(huo)(huo)(huo)性(xing)(xing)炭樣品中表(biao)(biao)現(xian)(xian)出(chu)(chu)*佳的(de)(de)(de)電(dian)(dian)(dian)(dian)化(hua)學性(xing)(xing)能，其中0.1A·g 的(de)(de)(de)電(dian)(dian)(dian)(dian)容為107.4F·g -1 -1.對稱雙電(dian)(dian)(dian)(dian)極電(dian)(dian)(dian)(dian)池(chi)。隨著電(dian)(dian)(dian)(dian)流密度大(da)于1，這些(xie)活(huo)(huo)(huo)性(xing)(xing)炭基(ji)超級電(dian)(dian)(dian)(dian)容器(qi)的(de)(de)(de)電(dian)(dian)(dian)(dian)容僅(jin)大(da)于1A·g -而略有(you)(you)變化(hua)。所有(you)(you)超級電(dian)(dian)(dian)(dian)容器(qi)在1中顯(xian)示出(chu)(chu)優異的(de)(de)(de)電(dian)(dian)(dian)(dian)化(hua)學穩定性(xing)(xing)A·g -1的(de)(de)(de) 充放電(dian)(dian)(dian)(dian)循環5000次后，LSC-1型超級電(dian)(dian)(dian)(dian)容器(qi)的(de)(de)(de)電(dian)(dian)(dian)(dian)容保持在92.6%以上。這些(xie)結果表(biao)(biao)明，纖維(wei)材料是合理設(she)計(ji)和制(zhi)備(bei)具(ju)有(you)(you)高表(biao)(biao)面(mian)積和優良電(dian)(dian)(dian)(dian)化(hua)學性(xing)(xing)能的(de)(de)(de)活(huo)(huo)(huo)性(xing)(xing)炭的(de)(de)(de)好(hao)候選(xuan)人。