Cation additives can efficiently enhance the total electrochemical capabilities of zinc-ion hybrid capacitors (ZHCs).However their energy storage mechanisms in zinc-based systems are still under debate.Herein,we modul...Cation additives can efficiently enhance the total electrochemical capabilities of zinc-ion hybrid capacitors (ZHCs).However their energy storage mechanisms in zinc-based systems are still under debate.Herein,we modulate the electrolyte and achieve dual-ion storage by adding magnesium ions.And we assemble several Zn//activated carbon devices with different electrolyte concentrations and investigate their electrochemical reaction dynamic behaviors.The zinc-ion capacitor with Mg^(2+)mixed solution delivers 82 mAh·g^(-1)capacity at 1 A·g^(-1) and maintains 91%of the original capacitance after 10000 cycling.It is superior to the other assembled zinc-ion devices in single-component electrolytes.The finding demonstrates that the double-ion storage mechanism enables the superior rate performance and long cycle lifetime of ZHCs.展开更多
Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio ...Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio of 1:0.5,temperature of 120°C and time of 1 h at Mg^(2+)concentration of 2 mol/L.Spherical flower-like Mg(OH)_(2) composed of ultra-thin sheets exhibits an excellent adsorption ability for Ni^(2+),Cu^(2+),Zn^(2+),Pb^(2+),Fe^(3+)and Co^(2+),and the adsorption reaches the equilibrium in 6 min.The maximum adsorption capacities of the studied heavy metal ions onto Mg(OH)_(2) at 20°C are 58.55,85.84,44.94,485.44,625.00 and 27.86 mg/g,respectively.The adsorption is well fitted by the Langmuir model,indicating that the adsorption is monolayer.The adsorption kinetics follows the pseudo-second-order model.Chemisorption is the operative mechanism.Spherical flower-like Mg(OH)_(2) is a qualified candidate for heavy metal ions removal.展开更多
基金financially supported by the National Natural Science Foundation of China (No.52172218)。
文摘Cation additives can efficiently enhance the total electrochemical capabilities of zinc-ion hybrid capacitors (ZHCs).However their energy storage mechanisms in zinc-based systems are still under debate.Herein,we modulate the electrolyte and achieve dual-ion storage by adding magnesium ions.And we assemble several Zn//activated carbon devices with different electrolyte concentrations and investigate their electrochemical reaction dynamic behaviors.The zinc-ion capacitor with Mg^(2+)mixed solution delivers 82 mAh·g^(-1)capacity at 1 A·g^(-1) and maintains 91%of the original capacitance after 10000 cycling.It is superior to the other assembled zinc-ion devices in single-component electrolytes.The finding demonstrates that the double-ion storage mechanism enables the superior rate performance and long cycle lifetime of ZHCs.
基金supported by the National Natural Science Foundation of China (Nos. 51774070 and 52004165)the Science and Technology Project of Yunnan Province, China (No. 202101AS070029)
文摘Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio of 1:0.5,temperature of 120°C and time of 1 h at Mg^(2+)concentration of 2 mol/L.Spherical flower-like Mg(OH)_(2) composed of ultra-thin sheets exhibits an excellent adsorption ability for Ni^(2+),Cu^(2+),Zn^(2+),Pb^(2+),Fe^(3+)and Co^(2+),and the adsorption reaches the equilibrium in 6 min.The maximum adsorption capacities of the studied heavy metal ions onto Mg(OH)_(2) at 20°C are 58.55,85.84,44.94,485.44,625.00 and 27.86 mg/g,respectively.The adsorption is well fitted by the Langmuir model,indicating that the adsorption is monolayer.The adsorption kinetics follows the pseudo-second-order model.Chemisorption is the operative mechanism.Spherical flower-like Mg(OH)_(2) is a qualified candidate for heavy metal ions removal.
