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
水系超级电容器具有能量密度高,循环稳定性好,安全性高等优势,但低能量密度阻碍了其进一步应用.通过一种简单有效的方法得到具有高能量密度和宽电压的水系超级电容器依旧面临挑战.本工作设计了一种三氧化二钒/碳纳米空心球(H-V_(2)O_(3)...水系超级电容器具有能量密度高,循环稳定性好,安全性高等优势,但低能量密度阻碍了其进一步应用.通过一种简单有效的方法得到具有高能量密度和宽电压的水系超级电容器依旧面临挑战.本工作设计了一种三氧化二钒/碳纳米空心球(H-V_(2)O_(3)/C)电极,并将其应用于水系超级电容器.碳的引入可以提高材料的导电性和稳定性,同时空心结构有利于提高电化学活性面积,提供快速的离子传输通道.此外,这种集成电极可同时工作于正极和负极电压窗口.因此,H-V_(2)O_(3)/C集成电极在-1.1–1.3 V的电压窗口下具有708.6 F g^(-1)的比容量.基于其多重储能机制,得到的水系对称超级电容器比传统的(非)对称超级电容器具有更高的电压窗口和能量密度.在2.4 V的宽电压下工作,当功率密度为1204.6 W kg^(-1)时具有96.8 W h kg^(-1)的高能量密度,同时具有优良的循环稳定性.本研究对电极材料的设计和制备具有一定的启发意义,为开发宽电压水系超级电容器开辟了一条新途径.展开更多
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)
文摘水系超级电容器具有能量密度高,循环稳定性好,安全性高等优势,但低能量密度阻碍了其进一步应用.通过一种简单有效的方法得到具有高能量密度和宽电压的水系超级电容器依旧面临挑战.本工作设计了一种三氧化二钒/碳纳米空心球(H-V_(2)O_(3)/C)电极,并将其应用于水系超级电容器.碳的引入可以提高材料的导电性和稳定性,同时空心结构有利于提高电化学活性面积,提供快速的离子传输通道.此外,这种集成电极可同时工作于正极和负极电压窗口.因此,H-V_(2)O_(3)/C集成电极在-1.1–1.3 V的电压窗口下具有708.6 F g^(-1)的比容量.基于其多重储能机制,得到的水系对称超级电容器比传统的(非)对称超级电容器具有更高的电压窗口和能量密度.在2.4 V的宽电压下工作,当功率密度为1204.6 W kg^(-1)时具有96.8 W h kg^(-1)的高能量密度,同时具有优良的循环稳定性.本研究对电极材料的设计和制备具有一定的启发意义,为开发宽电压水系超级电容器开辟了一条新途径.
