電(dian)(dian)(dian)(dian)(dian)(dian)化(hua)學(xue)雙(shuang)層電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)又稱超(chao)(chao)級電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)，通過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)解(jie)液(ye)離(li)子在(zai)高(gao)(gao)表面(mian)積電(dian)(dian)(dian)(dian)(dian)(dian)極表面(mian)的(de)(de)可(ke)(ke)逆吸(xi)脫附來儲(chu)能(neng)。由于(yu)(yu)不涉及氧(yang)化(hua)還原反應(ying)等(deng)電(dian)(dian)(dian)(dian)(dian)(dian)荷轉移(yi)動(dong)力學(xue)限制，超(chao)(chao)級電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)可(ke)(ke)以極高(gao)(gao)的(de)(de)充放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)速率下運行，具有(you)達百萬次的(de)(de)良好循環能(neng)力，使得它們廣泛應(ying)用于(yu)(yu)儲(chu)能(neng)領(ling)域。石(shi)(shi)(shi)墨(mo)烯理論(lun)上可(ke)(ke)具有(you)550 F/g的(de)(de)比容(rong)(rong)量(liang)，作為(wei)超(chao)(chao)級電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)電(dian)(dian)(dian)(dian)(dian)(dian)極材料備受關注(zhu)。然而目(mu)前石(shi)(shi)(shi)墨(mo)烯基(ji)材料的(de)(de)性能(neng)仍(reng)遠遠低于(yu)(yu)預(yu)期。一方面(mian)，石(shi)(shi)(shi)墨(mo)烯的(de)(de)量(liang)子電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)已被(bei)證明在(zai)雙(shuang)電(dian)(dian)(dian)(dian)(dian)(dian)層電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)的(de)(de)建立中起著關鍵作用；另一方面(mian)，界(jie)面(mian)電(dian)(dian)(dian)(dian)(dian)(dian)化(hua)學(xue)是決定(ding)超(chao)(chao)級電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)儲(chu)能(neng)性能(neng)的(de)(de)關鍵因素，涉及到離(li)子在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)極孔(kong)道(dao)內的(de)(de)傳輸擴散(san)、離(li)子在(zai)碳(tan)表面(mian)的(de)(de)吸(xi)/脫附等(deng)過(guo)程(cheng)。石(shi)(shi)(shi)墨(mo)烯-電(dian)(dian)(dian)(dian)(dian)(dian)解(jie)液(ye)界(jie)面(mian)動(dong)態電(dian)(dian)(dian)(dian)(dian)(dian)荷分離(li)機(ji)制仍(reng)然未得到良好解(jie)決，阻礙了高(gao)(gao)性能(neng)二維或三維石(shi)(shi)(shi)墨(mo)烯電(dian)(dian)(dian)(dian)(dian)(dian)極的(de)(de)進一步發展。

石(shi)英微晶天(tian)平用于原位(wei)電(dian)化學檢測示意(yi)圖（左），觀測到的石(shi)墨烯表(biao)面離(li)子響(xiang)應（右）

近日，中(zhong)國(guo)(guo)科學技(ji)術大學朱(zhu)彥武課(ke)題(ti)(ti)組提出，低缺陷含量(liang)的(de)單(dan)層(ceng)石(shi)(shi)(shi)墨(mo)烯(xi)(xi)可為從理解(jie)極(ji)化(hua)作(zuo)(zuo)用下石(shi)(shi)(shi)墨(mo)烯(xi)(xi)界(jie)面(mian)離(li)(li)子吸附(fu)/相互作(zuo)(zuo)用提供(gong)了(le)一個優(you)良模版：既(ji)消除(chu)了(le)孔道(dao)離(li)(li)子受限效(xiao)應(ying)，又不(bu)受大多(duo)數(shu)多(duo)孔碳材料中(zhong)孔隙或缺陷的(de)影響(xiang)（National Science Review, 2019; //academic.oup.com/nsr/advance -article /doi/10.1093/nsr/ nwz140/5569389）。基于此，該課(ke)題(ti)(ti)組聯合法國(guo)(guo)Patrice Simon課(ke)題(ti)(ti)組，采用電(dian)(dian)化(hua)學阻抗(kang)譜和電(dian)(dian)化(hua)學石(shi)(shi)(shi)英晶體微量(liang)天平系(xi)統聯用，原位研究(jiu)了(le)離(li)(li)子液體（EMI-TFSI）電(dian)(dian)解(jie)質在單(dan)層(ceng)石(shi)(shi)(shi)墨(mo)烯(xi)(xi)表面(mian)的(de)動力(li)學響(xiang)應(ying)。研究(jiu)發現，在石(shi)(shi)(shi)墨(mo)烯(xi)(xi)正(zheng)極(ji)化(hua)區間(jian)(jian)，電(dian)(dian)荷(he)儲(chu)存受帶正(zheng)電(dian)(dian)的(de)團簇類離(li)(li)子脫附(fu)主導；在負極(ji)化(hua)區間(jian)(jian)，石(shi)(shi)(shi)墨(mo)烯(xi)(xi)表面(mian)質量(liang)變(bian)化(hua)較(jiao)小，顯示表面(mian)離(li)(li)子重排效(xiao)應(ying)。隨著施(shi)加(jia)電(dian)(dian)勢的(de)增加(jia)，兩種(zhong)類型的(de)界(jie)面(mian)響(xiang)應(ying)主導著雙電(dian)(dian)層(ceng)的(de)變(bian)化(hua)，導致雙電(dian)(dian)層(ceng)電(dian)(dian)容增加(jia)。該研究(jiu)為進(jin)一步(bu)理解(jie)石(shi)(shi)(shi)墨(mo)烯(xi)(xi)-電(dian)(dian)解(jie)液界(jie)面(mian)結構以及石(shi)(shi)(shi)墨(mo)烯(xi)(xi)雙電(dian)(dian)層(ceng)儲(chu)能提供(gong)了(le)基礎。

研(yan)究(jiu)(jiu)成果(guo)以“Charge Storage Mechanisms of Single Layer Graphene in Ionic Liquid”為(wei)題(ti)發表在雜志(zhi)《Journal of the American Chemical Society》。該研(yan)究(jiu)(jiu)工作得到(dao)了自然(ran)科學(xue)基金基金委、the Agence Nationale de la Recherche、國家留學(xue)基金（CSC）項目(mu)的(de)支持。

本文來自石墨烯雜志，本文觀點不代表利特納米立場，轉載請聯系原作者。