Supercapacitors(SCs)are high-power energy storage devices with ultra-fast charge/discharge properties.SCs using concentrated aqueous-based electrolytes can work at low temperatures due to their intrinsic properties,such as higher freezing point depression(FPD)and robustness.Besides the traditional organic-and aqueous-based(salt-in-water)electrolytes used in SCs,water-in-salt(WISE)sodium per-chlorate electrolytes offer high FPD,non-flammability,and low-toxicity conditions,allowing the fabrica-tion of safer,environmentally friendly,and more robust devices.For the first time,this work reports a comprehensive study regarding WISE system's charge-storage capabilities and physicochemical proper-ties under low-temperature conditions(T＜0℃)using mesoporous carbon-based electrodes.The effect of temperature reduction on the electrolyte viscosity and electrical properties was investigated using differ-ent techniques and the in-situ(or operando)Raman spectroscopy under dynamic polarization conditions.The cell voltage,equivalent series resistance,and specific capacitance were investigated as a function of the temperature.The cell voltage(U)increased～50％,while the specific capacitance decreased～20％when the temperature was reduced from 25℃to-10℃.As a result,the maximum specific energy(E=CU2/2)increased～100％.Therefore,low-temperature WISEs are promising candidates to improve the energy-storage characteristics in SCs.

Jo?o Pedro A.Santos;Manuel J.Pinzón;érick A.Santos;Rafael Vicentini;Cesar J.B.Pagan;Leonardo M.Da Silva;Hudson Zanin

Brazilian Renewable Energies,Center for Innovation on New Energies,School of Electrical and Computer Engineering,University of Campinas,Campinas,Sao Paulo 13083-852,Brazil;Department of Semiconductors,Instruments and Photonics,School of Electrical and Computer Engineering,University of Campinas,Campinas,Sao Paulo 13083-852,Brazil;Laboratory of Fundamental and Applied Electrochemistry,Department of Chemistry,Federal University of Jequitinhonha e Mucuri's Valley,Diamantina,Minas Gerais 39100-000,Brazil

能源化学

[1]Jo?o Pedro A.Santos;Manuel J.Pinzón;érick A.Santos;Rafael Vicentini;Cesar J.B.Pagan;Leonardo M.Da Silva;Hudson Zanin-.Boosting energy-storage capability in carbon-based supercapacitors using low-temperature water-in-salt electrolytes)[J].能源化学,2022(07):521-530

CU2,WISEs

Boosting,energy,storage,capability,carbon,supercapacitors,using,water,salt,electrolytes,Supercapacitors,SCs,are,power,devices,ultra,fast,discharge,properties,concentrated,aqueous,work,temperatures,due,their,intrinsic,such,higher,freezing,point,depression,FPD,robustness,Besides,traditional,organic,used,sodium,chlorate,offer,flammability,toxicity,conditions,allowing,fabrica,safer,environmentally,friendly,more,For,first,this,reports,comprehensive,study,regarding,system,capabilities,physicochemical,under,mesoporous,electrodes,effect,reduction,viscosity,electrical,was,investigated,differ,techniques,situ,operando,Raman,spectroscopy,dynamic,polarization,cell,voltage,equivalent,series,resistance,specific,capacitance,were,function,increased,while,decreased,when,reduced,from,result,maximum,Therefore,promising,candidates,improve,characteristics

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