An effective'salt in dimethyl sulfoxide/water'electrolyte enables high-voltage supercapacitor operated at-50℃  

作　　者：Yingbin Liu Chang Yu Xuedan Song Siyi Hou Shuqin Lan Jinhe Yu Yuanyang Xie Jieshan Qiu 

机构地区：[1]State Key Lab of Fine Chemicals,Frontier Science Center for Smart Materials,School of Chemical Engineering,Liaoning Key Lab for Energy Materials and Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China [2]School of Chemistry,Frontier Science Center for Smart Materials,Liaoning Key Lab for Energy Materials and Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China [3]College of Chemical Engineering,State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology,Beijing 100029,China

出　　处：《Journal of Energy Chemistry》2024年第6期361-367,I0009,共8页能源化学（英文版）

基　　金：partly supported by the National Key R&D Program of China(2022YFB4101602);the National Natural Science Foundation of China(22078052);the Fundamental Research Funds for the Central Universities(DUT22ZD207)。

摘　　要：Compared with organic electrolytes,aqueous electrolytes exhibit significantly higher ionic conductivity and possess inherent safety features,showcasing unique advantages in supercapacitors.However,challenges remain for low-salt aqueous electrolytes operating at high voltage and low temperature.Herein,we report a low-salt(0.87 m,m means mol kg^(-1))'salt in dimethyl sulfoxide/water'hybrid electrolyte with non-flammability via hybridizing aqueous electrolyte with an organic co-solvent of dimethyl sulfoxide(hydrogen bond acceptor).As a result,the 0.87 m hybrid electrolyte exhibits enhanced electrochemical stability,a freezing temperature below-50℃,and an outstanding ionic conductivity of 0.52mS cm~(-1)at-50℃.Dimethyl sulfoxide can anchor water molecules through intermolecular hydrogen bond interaction,effectively reinforcing the stability of water in the hybrid electrolyte.Furthermore,the interaction between dimethyl sulfoxide and water molecules diminishes the involvement of water in the generation of ordered ice crystals,finally facilitating the low-temperature performance of the hybrid electrolyte.When paired with the 0.87 m'salt in dimethyl sulfoxide/water'hybrid electrolyte,the symmetric supercapacitor presents a 2.0 V high operating voltage at 25℃,and can operate stably at-50℃.Importantly,the suppressed electrochemical reaction of water at-50℃further leads to the symmetric supercapacitor operated at a higher voltage of 2.6 V.This modification strategy opens an effective avenue to develop low-salt electrolytes for high-voltage and low-temperature aqueous supercapacitors.

关 键 词：Dimethyl sulfoxide CO-SOLVENT High voltage Low temperature SUPERCAPACITORS 

分 类 号：O646[理学—物理化学] TM53[理学—化学]