Manufacturing cost-effective electrolytes featuring high(electro)chemical stability,high Zn anode reversibility,good ionic conductivity,and environmental benignity is highly desired for rechargeable aqueous zinc-based...Manufacturing cost-effective electrolytes featuring high(electro)chemical stability,high Zn anode reversibility,good ionic conductivity,and environmental benignity is highly desired for rechargeable aqueous zinc-based energy storage devices but remains a great challenge.Herein,a solute-solvent dual engineering strategy using lithium bis(trifluoromethane)sulfonimide(LiTFSI)and inexpensive poly(ethylene glycol)(PEG,M_(n)=200)as a coadditive with an optimized ratio accomplished an all-round performance enhancement of electrolytes.Due to the synergistic inhibition of water activity and Zn^(2+)solvation structure reorganization by LiTFSI-PEG,as well as a stable F-rich interfacial layer and PEG adsorption on the Zn anode surface,dendrite-free Zn plating/stripping at nearly 100%Coulombic efficiency and stable cycling performance over 2000 h at 0.5 mA cm^(−2)was achieved.Importantly,the integrated Zn-ion hybrid supercapacitors are endowed with a wide voltage window of 0-2.2 V,superb cycling stability up to 10,000 cycles,and excellent temperature adaptability from-40°C to 50°C.The highest cutoffvoltage reached 2.1 V in Zn//LiMn_(2)O_(4)and Zn//VOPO_(4)full cells with a stable lifespan over 500 cycles.This work provides a promising strategy for the development of aqueous electrolytes with excellent com-prehensive properties for zinc-based energy storage.展开更多
The development of low-cost and eco-friendly aqueous electrolytes with a wide voltage window is the key to achieving safe high energy density supercapacitors(SCs).In this work,a molecular crowding electrolyte is prepa...The development of low-cost and eco-friendly aqueous electrolytes with a wide voltage window is the key to achieving safe high energy density supercapacitors(SCs).In this work,a molecular crowding electrolyte is prepared by simulating the crowded environment in living cells.Ion transport in the molecular crowding electrolyte can be effectively improved via reducing the molecular weight of the crowding agent,polyethylene glycol(PEG).The results show that PEG with a molecular weight of 200(PEG200)can significantly improve ionic conductivity while maintaining a wide voltage window.These advantages enable commercial activated carbon-based SCs to work at 2.5 V with high energy density,outstanding rate performance and good stability for more than 10,000 cycles.On this basis,three series of molecular crowding electrolytes using sodium perchlorate,lithium perchlorate,and sodium trifluoromethanesulfonate as salts are developed,demonstrating the versatility of PEG200 for wide-voltage aqueous electrolytes.展开更多
Aqueous supercapacitors(SCs)exhibit several advantages,including high-power density,cycling durability,and safety;however,the shortage of low energy density inhibits their further application.Acquiring an excellent pe...Aqueous supercapacitors(SCs)exhibit several advantages,including high-power density,cycling durability,and safety;however,the shortage of low energy density inhibits their further application.Acquiring an excellent performance upon using simple strategies would be beneficial,but remains challenging.Here,an integrated electrode of hollow V_(2)O_(3)/carbon nanospheres(H-V_(2)O_(3)/C)was designed and synthesized for SCs.The introduction of carbon can increase the conductivity and stability,whereas the hollow structure endows H-V_(2)O_(3)/C with a high specific surface area and rapid transport of ions.Moreover,the H-V_(2)O_(3)/C integrated electrode can simultaneously work in both negative and positive potential windows.Benefiting from these advantages,the H-V_(2)O_(3)/C integrated electrode exhibits a specific capacitance as high as 708.6 F g^(-1) in a wide voltage window of-1.1-1.3 V.Furthermore,stemming from the multiple energy storage mechanisms,the aqueous integrated full SC device exhibits a wider potential window and higher energy density than the traditional(a)symmetric ones.Therefore,the proposed device delivers a wide voltage window of 2.4 V with an energy density of 96.8 W h kg^(-1) at a power density of 1204.6 W kg^(-1),as well as superior cycling stability.This study enlightens the design and preparation of electrode materials,opening up a possible approach for developing wide-voltage aqueous SCs.展开更多
基金the National Natural Science Foundation of China(52073137,51763018)the International Science and Technology Cooperation of Jiangxi Province(20203BDH80W011)the Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education,Jiangxi Normal University(KFSEMC-202204).
文摘Manufacturing cost-effective electrolytes featuring high(electro)chemical stability,high Zn anode reversibility,good ionic conductivity,and environmental benignity is highly desired for rechargeable aqueous zinc-based energy storage devices but remains a great challenge.Herein,a solute-solvent dual engineering strategy using lithium bis(trifluoromethane)sulfonimide(LiTFSI)and inexpensive poly(ethylene glycol)(PEG,M_(n)=200)as a coadditive with an optimized ratio accomplished an all-round performance enhancement of electrolytes.Due to the synergistic inhibition of water activity and Zn^(2+)solvation structure reorganization by LiTFSI-PEG,as well as a stable F-rich interfacial layer and PEG adsorption on the Zn anode surface,dendrite-free Zn plating/stripping at nearly 100%Coulombic efficiency and stable cycling performance over 2000 h at 0.5 mA cm^(−2)was achieved.Importantly,the integrated Zn-ion hybrid supercapacitors are endowed with a wide voltage window of 0-2.2 V,superb cycling stability up to 10,000 cycles,and excellent temperature adaptability from-40°C to 50°C.The highest cutoffvoltage reached 2.1 V in Zn//LiMn_(2)O_(4)and Zn//VOPO_(4)full cells with a stable lifespan over 500 cycles.This work provides a promising strategy for the development of aqueous electrolytes with excellent com-prehensive properties for zinc-based energy storage.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(52073137,51763018,21704038)the NSFC-DFG Joint Research Project(51761135114)the Natural Science Foundation of Jiangxi Province(20203BDH80W011,20202ZDB01009,20192BCB23001).
文摘The development of low-cost and eco-friendly aqueous electrolytes with a wide voltage window is the key to achieving safe high energy density supercapacitors(SCs).In this work,a molecular crowding electrolyte is prepared by simulating the crowded environment in living cells.Ion transport in the molecular crowding electrolyte can be effectively improved via reducing the molecular weight of the crowding agent,polyethylene glycol(PEG).The results show that PEG with a molecular weight of 200(PEG200)can significantly improve ionic conductivity while maintaining a wide voltage window.These advantages enable commercial activated carbon-based SCs to work at 2.5 V with high energy density,outstanding rate performance and good stability for more than 10,000 cycles.On this basis,three series of molecular crowding electrolytes using sodium perchlorate,lithium perchlorate,and sodium trifluoromethanesulfonate as salts are developed,demonstrating the versatility of PEG200 for wide-voltage aqueous electrolytes.
基金financially supported by the National Natural Science Foundation of China (NSFC, 52073137, 21704038and 51763018)the NSFC-DFG Joint Research Project (51761135114)+1 种基金the Natural Science Foundation of Jiangxi Province (20192BCB23001and 20202ZDB01009)the National Postdoctoral Program for Innovative Talents (BX201700112)
文摘Aqueous supercapacitors(SCs)exhibit several advantages,including high-power density,cycling durability,and safety;however,the shortage of low energy density inhibits their further application.Acquiring an excellent performance upon using simple strategies would be beneficial,but remains challenging.Here,an integrated electrode of hollow V_(2)O_(3)/carbon nanospheres(H-V_(2)O_(3)/C)was designed and synthesized for SCs.The introduction of carbon can increase the conductivity and stability,whereas the hollow structure endows H-V_(2)O_(3)/C with a high specific surface area and rapid transport of ions.Moreover,the H-V_(2)O_(3)/C integrated electrode can simultaneously work in both negative and positive potential windows.Benefiting from these advantages,the H-V_(2)O_(3)/C integrated electrode exhibits a specific capacitance as high as 708.6 F g^(-1) in a wide voltage window of-1.1-1.3 V.Furthermore,stemming from the multiple energy storage mechanisms,the aqueous integrated full SC device exhibits a wider potential window and higher energy density than the traditional(a)symmetric ones.Therefore,the proposed device delivers a wide voltage window of 2.4 V with an energy density of 96.8 W h kg^(-1) at a power density of 1204.6 W kg^(-1),as well as superior cycling stability.This study enlightens the design and preparation of electrode materials,opening up a possible approach for developing wide-voltage aqueous SCs.
