Due to insufficient energy density,supercapacitors(SCs)with preeminent-power and long cycle stability cannot be implemented in some practical applications.Exploring hybrid materials with redox activity to emerge high ...Due to insufficient energy density,supercapacitors(SCs)with preeminent-power and long cycle stability cannot be implemented in some practical applications.Exploring hybrid materials with redox activity to emerge high specific capacitance in ionic liquid(IL)electrolytes can solve this problem.Herein,we report a redox-organic molecule 2,6-diaminoanthraquinone(DAAQ)modified MXene(Ti3C2Tx)/Graphene(DAAQ-M/G)composite material.With the assist of graphene oxide(GO),MXene and graphene fabricate a three-dimensional(3D)interconnected structure as a conductive framework,which inhibits self-stacking of MXene monolayers and ensures high electronic conductivity.Meanwhile,DAAQ is loaded onto the M/G framework through covalent/non-covalent functionalization.The DAAQ as a spacer effectively enlarges the interlayer spacing of MXene nanosheets,and meanwhile produces reversible redox reactions during charge/discharge processes to provide additional Faradaic contribution to capacity.Therefore,the specific capacitance(capacity)of the DAAQ-M/G as the negative electrode material reaches to 226 F g^(-1)(306 C g^(-1))at 1 A g^(-1)in 1-ethyl-3-methylimidazolium tetrafluoroborate(EmimBF4)electrolyte.Furthermore,an asymmetric supercapacitor(ASC)is assembled using DAAQ-M/G as the negative electrode and self-prepared organic molecule hydroquinone modified reduced graphene oxide(HQ-RGO)material as the positive electrode,with a high energy density of 43 Wh kg^(-1)at high power density of 1669 Wkg^(-1).The ASC can maintain 80%of initial specific capacitance after 9000 cycles.This research can provide better support to develop advanced organic molecules-modified MXene composite materials for ionic liquid-based SCs.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22173028,21873026).
文摘Due to insufficient energy density,supercapacitors(SCs)with preeminent-power and long cycle stability cannot be implemented in some practical applications.Exploring hybrid materials with redox activity to emerge high specific capacitance in ionic liquid(IL)electrolytes can solve this problem.Herein,we report a redox-organic molecule 2,6-diaminoanthraquinone(DAAQ)modified MXene(Ti3C2Tx)/Graphene(DAAQ-M/G)composite material.With the assist of graphene oxide(GO),MXene and graphene fabricate a three-dimensional(3D)interconnected structure as a conductive framework,which inhibits self-stacking of MXene monolayers and ensures high electronic conductivity.Meanwhile,DAAQ is loaded onto the M/G framework through covalent/non-covalent functionalization.The DAAQ as a spacer effectively enlarges the interlayer spacing of MXene nanosheets,and meanwhile produces reversible redox reactions during charge/discharge processes to provide additional Faradaic contribution to capacity.Therefore,the specific capacitance(capacity)of the DAAQ-M/G as the negative electrode material reaches to 226 F g^(-1)(306 C g^(-1))at 1 A g^(-1)in 1-ethyl-3-methylimidazolium tetrafluoroborate(EmimBF4)electrolyte.Furthermore,an asymmetric supercapacitor(ASC)is assembled using DAAQ-M/G as the negative electrode and self-prepared organic molecule hydroquinone modified reduced graphene oxide(HQ-RGO)material as the positive electrode,with a high energy density of 43 Wh kg^(-1)at high power density of 1669 Wkg^(-1).The ASC can maintain 80%of initial specific capacitance after 9000 cycles.This research can provide better support to develop advanced organic molecules-modified MXene composite materials for ionic liquid-based SCs.
