活性炭的電化學(xue)性能(neng)

　　能(neng)源問題是21世紀(ji)活(huo)性(xing)(xing)炭(tan)電化學(xue)性(xing)(xing)能(neng)*顯著的(de)全(quan)球挑(tiao)戰之一。全(quan)球對(dui)能(neng)源供應和(he)環(huan)境保護的(de)需(xu)求(qiu)急劇增(zeng)(zeng)加，迫使世界面臨經濟危機。據*近報(bao)道，全(quan)球能(neng)耗每年約為4.1×10 20 J--其(qi)80%來(lai)自(zi)不(bu)可再生碳密集型化石(shi)燃(ran)料，包(bao)括煤(mei)、石(shi)油和(he)天然氣(qi)。過度依賴燃(ran)燒化石(shi)燃(ran)料帶來(lai)了許多環(huan)境問題，增(zeng)(zeng)加了全(quan)球經濟的(de)負擔。隨著世界的(de)不(bu)斷(duan)發展，能(neng)源需(xu)求(qiu)迅速增(zeng)(zeng)長，地球不(bu)可再生能(neng)源總量相當(dang)有限。因此，為了滿足(zu)日益增(zeng)(zeng)長的(de)能(neng)源需(xu)求(qiu)，減(jian)少對(dui)環(huan)境的(de)應力，需(xu)要安全(quan)、實用、可持(chi)續、性(xing)(xing)能(neng)良好的(de)能(neng)量轉換和(he)存儲設備。

　　電(dian)(dian)化學電(dian)(dian)容(rong)(rong)器(qi)*近引(yin)起了人們的(de)(de)(de)極大興趣，包(bao)括顯著的(de)(de)(de)循環效率(lv)、預期的(de)(de)(de)循環壽命、快速(su)充放電(dian)(dian)率(lv)和優良的(de)(de)(de)功率(lv)密(mi)度，以(yi)(yi)及便攜式電(dian)(dian)子、混合電(dian)(dian)動汽(qi)車和存(cun)儲器(qi)的(de)(de)(de)備(bei)用設備(bei)。毫無(wu)疑問，活(huo)(huo)性(xing)炭雙層電(dian)(dian)容(rong)(rong)器(qi)的(de)(de)(de)性(xing)能主(zhu)要取(qu)決于其電(dian)(dian)極材料的(de)(de)(de)類型(xing)和形式。超級電(dian)(dian)容(rong)(rong)器(qi)的(de)(de)(de)紋理電(dian)(dian)位電(dian)(dian)極材料研(yan)究以(yi)(yi)各種形式進(jin)行了報道。以(yi)(yi)活(huo)(huo)性(xing)炭為材料，如(ru)活(huo)(huo)性(xing)炭、石墨烯、碳納米結(jie)構，如(ru)管道和纖維、來自碳化物的(de)(de)(de)碳等。

　　此外(wai)，活(huo)性(xing)炭(tan)(tan)具有多(duo)孔(kong)結構豐富、雜原(yuan)子自(zi)摻雜、物(wu)理化學穩定性(xing)和(he)環保(bao)等(deng)優(you)點，廣泛應用(yong)于能(neng)(neng)(neng)(neng)源相關領(ling)域，以滿足(zu)能(neng)(neng)(neng)(neng)源供應的迫切需(xu)求。截至目前(qian)，堅(jian)果殼(ke)、椰殼(ke)、木材(cai)、動物(wu)骨、纖維等(deng)各種活(huo)性(xing)炭(tan)(tan)材(cai)料已被廣泛用(yong)作(zuo)制造電容器的前(qian)體。大多(duo)數報(bao)告稱，活(huo)性(xing)炭(tan)(tan)的儲能(neng)(neng)(neng)(neng)性(xing)能(neng)(neng)(neng)(neng)超過了其他非(fei)活(huo)性(xing)炭(tan)(tan)材(cai)料的儲能(neng)(neng)(neng)(neng)性(xing)能(neng)(neng)(neng)(neng)。

　　活性炭的電化學性能

　　5%的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)PTFE，乙(yi)炔碳黑10%，活性(xing)炭(tan)85%。將(jiang)所有材(cai)料均(jun)勻混合，然后在(zai)(zai)(zai)1.4MPa將(jiang)其壓在(zai)(zai)(zai)鎳泡沫基材(cai)上，然后在(zai)(zai)(zai)真空(kong)烘(hong)箱中壓在(zai)(zai)(zai)110℃干燥(zao)12小時。每(mei)個集電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器上的(de)活性(xing)物質(zhi)(zhi)量約(yue)為4.7mg·cm -2。6.通過多孔膜分離(li)M KOH對稱雙電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池組裝電(dian)(dian)(dian)(dian)(dian)(dian)(dian)解質(zhi)(zhi)水溶液。采用循環伏(fu)安法(CV)，恒電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流充放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(GCD)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)化學(xue)(xue)阻抗光(guang)譜(EIS)研究樣(yang)品的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容性(xing)能。在(zai)(zai)(zai)0.01Hz-100KHz在(zai)(zai)(zai)5的(de)頻率范(fan)圍內mV在(zai)(zai)(zai)開路電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位下測(ce)量范(fan)圍EIS光(guang)譜。所有電(dian)(dian)(dian)(dian)(dian)(dian)(dian)化學(xue)(xue)測(ce)量均(jun)在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)化學(xue)(xue)工作站(zhan)進行。所有試驗均(jun)在(zai)(zai)(zai)室溫(wen)下進行。

　　活性炭的形狀和結構(gou)

　　四個活性(xing)炭樣(yang)品(pin)(LSC-1-4)的(de)XRD圖(tu)譜顯示沒有尖銳和強峰(feng)(如圖(tu)1所示)，表(biao)示所有活性(xing)炭樣(yang)品(pin)的(de)非晶狀態。一(yi)方面(mian)位于23左右°位于44的(de)寬峰(feng)和寬峰(feng)°弱峰(feng)是無(wu)定形石(shi)墨(mo)碳的(de)特征(zheng)峰(feng)，表(biao)明(ming)LSC樣(yang)品(pin)的(de)石(shi)墨(mo)化(hua)程度有限。另一(yi)方面(mian)，以44°中心弱峰(feng)的(de)出現表(biao)明(ming)電導率(lv)的(de)提(ti)高(gao)。特別地，LSC-1在44°與其他(ta)樣(yang)品(pin)相(xiang)比(bi)，觀察到的(de)尖銳峰(feng)值表(biao)明(ming)，LSC-石(shi)墨(mo)化(hua)程度提(ti)高(gao)。

　　電化(hua)學(xue)表征活性炭

　　基于活性(xing)炭(tan)(tan)(tan)的(de)(de)(de)超(chao)級電(dian)(dian)(dian)容(rong)(rong)器的(de)(de)(de)活性(xing)炭(tan)(tan)(tan)樣(yang)品(SC-LSC)的(de)(de)(de)電(dian)(dian)(dian)容(rong)(rong)性(xing)，LSC-3和(he)LSC-4通(tong)過(guo)電(dian)(dian)(dian)化學技術序列進(jin)行評(ping)估，包括(kuo)室溫下CV，GCD和(he)EIS測試(shi)。圖(tu)(tu)2顯(xian)示(shi)了四個不同掃描(miao)(miao)速(su)(su)(su)率的(de)(de)(de)人SC-LSC的(de)(de)(de)CV電(dian)(dian)(dian)勢窗的(de)(de)(de)范圍為0-0.8V。如所(suo)見，所(suo)有(you)(you)超(chao)級電(dian)(dian)(dian)容(rong)(rong)活性(xing)炭(tan)(tan)(tan)在(zai)(zai)相對(dui)較低(di)(di)的(de)(de)(de)掃描(miao)(miao)速(su)(su)(su)率下具有(you)(you)理想的(de)(de)(de)矩形(xing)電(dian)(dian)(dian)容(rong)(rong)性(xing)能(neng)，即(ji)充(chong)電(dian)(dian)(dian) - 雙層(ceng)(ceng)電(dian)(dian)(dian)容(rong)(rong)器在(zai)(zai)放電(dian)(dian)(dian)過(guo)程中的(de)(de)(de)典型性(xing)質。即(ji)使在(zai)(zai)500 mV·s -在(zai)(zai)1的(de)(de)(de)高(gao)掃描(miao)(miao)速(su)(su)(su)率下，如圖(tu)(tu)2所(suo)示(shi)d，SC-LSCs的(de)(de)(de)CV由于樣(yang)品的(de)(de)(de)優良導電(dian)(dian)(dian)性(xing)和(he)低(di)(di)質量傳輸電(dian)(dian)(dian)阻，曲線(xian)保(bao)持了伏安曲線(xian)的(de)(de)(de)準矩形(xing)狀，幾乎沒有(you)(you)變形(xing)。顯(xian)然(ran)，短離(li)子通(tong)道和(he)電(dian)(dian)(dian)解質儲層(ceng)(ceng)的(de)(de)(de)快速(su)(su)(su)離(li)子運(yun)輸來自活性(xing)炭(tan)(tan)(tan)樣(yang)品的(de)(de)(de)分層(ceng)(ceng)孔結(jie)構(gou)。類似地(di)，超(chao)級電(dian)(dian)(dian)容(rong)(rong)活性(xing)炭(tan)(tan)(tan)由于理想的(de)(de)(de)分層(ceng)(ceng)多孔結(jie)構(gou)和(he)活性(xing)炭(tan)(tan)(tan)的(de)(de)(de)高(gao)表面積而(er)顯(xian)示(shi)出*高(gao)的(de)(de)(de)電(dian)(dian)(dian)容(rong)(rong)值。

　　碳(tan)化(hua)(hua)活(huo)(huo)化(hua)(hua)前，由(you)纖維材(cai)料合成四種活(huo)(huo)性(xing)(xing)炭(tan)。所(suo)有(you)制備的(de)(de)(de)(de)活(huo)(huo)性(xing)(xing)炭(tan)主(zhu)要表(biao)(biao)(biao)現(xian)為微孔結構。發(fa)現(xian)通過ZnCl 2活(huo)(huo)化(hua)(hua)法制備的(de)(de)(de)(de)活(huo)(huo)性(xing)(xing)炭(tan)表(biao)(biao)(biao)現(xian)出*大(da)的(de)(de)(de)(de)比表(biao)(biao)(biao)面(mian)積，在(zai)所(suo)有(you)活(huo)(huo)性(xing)(xing)炭(tan)樣品中(zhong)表(biao)(biao)(biao)現(xian)出*佳的(de)(de)(de)(de)電(dian)(dian)(dian)化(hua)(hua)學性(xing)(xing)能，其中(zhong)0.1A·g 的(de)(de)(de)(de)電(dian)(dian)(dian)容(rong)為107.4F·g -1 -1.對稱雙電(dian)(dian)(dian)極電(dian)(dian)(dian)池。隨著電(dian)(dian)(dian)流密度(du)大(da)于1，這(zhe)些活(huo)(huo)性(xing)(xing)炭(tan)基(ji)超級電(dian)(dian)(dian)容(rong)器的(de)(de)(de)(de)電(dian)(dian)(dian)容(rong)僅大(da)于1A·g -而(er)略有(you)變化(hua)(hua)。所(suo)有(you)超級電(dian)(dian)(dian)容(rong)器在(zai)1中(zhong)顯示出優異的(de)(de)(de)(de)電(dian)(dian)(dian)化(hua)(hua)學穩定性(xing)(xing)A·g -1的(de)(de)(de)(de) 充(chong)放電(dian)(dian)(dian)循環5000次后，LSC-1型超級電(dian)(dian)(dian)容(rong)器的(de)(de)(de)(de)電(dian)(dian)(dian)容(rong)保持在(zai)92.6%以(yi)上。這(zhe)些結果(guo)表(biao)(biao)(biao)明，纖維材(cai)料是合理設計和制備具有(you)高(gao)表(biao)(biao)(biao)面(mian)積和優良電(dian)(dian)(dian)化(hua)(hua)學性(xing)(xing)能的(de)(de)(de)(de)活(huo)(huo)性(xing)(xing)炭(tan)的(de)(de)(de)(de)好候選人。