The electrochemical reversibility of Mg in hybrid electrolytes based on mixtures of ionic liquid and glyme based organic solvents was investigated for applications in rechargeable magnesium batteries(RMBs). The electr...The electrochemical reversibility of Mg in hybrid electrolytes based on mixtures of ionic liquid and glyme based organic solvents was investigated for applications in rechargeable magnesium batteries(RMBs). The electrolytes demonstrate reversible reduction and oxidation of Mg only after being pre-treated with the dehydrating agent, magnesium borohydride, Mg[BH_4]_2, highlighting the importance of removing water in Mg based electrolytes. The addition magnesium di[bis(trifluoromethanesulfonyl)imide](Mg[TFSI]_2)(0.3 M) to N-butyl-n-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide [C4 mpyr][TFSI]/tetraglyme at a mole ratio of 1:2 showed stable CV cycling over almost 300 cycles while scanning electron microscopy(SEM) and X-ray diffraction(XRD) confirmed Mg deposition, showing non-dendritic morphology and a well-aligned growth. Further thermogravimetric analysis(TGA) demonstrated a mass retention of 79% at 250℃ for this electrolyte suggesting that the presence of the ionic liquid increases thermal stability substantially making these hybrid electrolytes compatible for RMBs.展开更多
Aqueous rechargeable zinc-based batteries have attracted increasing interest and been considered potential alternatives for state-of-the-art lithium-ion batteries because of the low cost and high safety.Many cathode m...Aqueous rechargeable zinc-based batteries have attracted increasing interest and been considered potential alternatives for state-of-the-art lithium-ion batteries because of the low cost and high safety.Many cathode materials have been gradually developed and demonstrated excellent electrochemical performances.However,the complex electrochemistry,inevitable hydrogen release,and zinc corrosion severely hinder the practical application.The most concerned Zn-MnO_(2)batteries still suffer from the Mn dissolution and formation of byproducts.By adding organic solvents to inhibit the activity of water molecules,the hydrous organic electrolytes provide a sound solution for eliminating the unfavorable factors.Here we report a tetraethylene glycol dimethyl ether-based hydrous organic electrolyte consisting of LiClO_(4)·3H_(2)O and Zn(ClO4)2·6H2O,and a birnessite-type MnO_(2)cathode material for Zn-MnO_(2)batteries.The Li+/Zn2+ions co-(de)insertion mechanism is ascertained by the structural and morphological analyses.The electrostatic interaction between inserted ions and crystal structure is reduced effectively by employment of monovalent Li+ions,which ensures structural stability of cathode materials.Hydrous tetraglyme electrolyte inhibits the activity of water molecules and thus avoids the formation of byproduct Zn_(4)ClO_(4)(OH)7·Meanwhile,highly stable Zn plating/stripping for over 1500 h,an average coulombic efficiency of>99%in long-term cycling,and ultralong storage life(the cells can work well after stored over 1 year)are simultaneously realized in the novel electrolyte.Benefitting from these aspects,the Zn-MnO_(2)batteries manifest high specific capacity of 132 mA h g^(-1),an operating voltage of 1.25 V,and a capacity retention of>98%after 1000 cycles at a current density of 200 mA g^(-1).展开更多
基金support from the Australian Research Council for his Australian Laureate Fellowship
文摘The electrochemical reversibility of Mg in hybrid electrolytes based on mixtures of ionic liquid and glyme based organic solvents was investigated for applications in rechargeable magnesium batteries(RMBs). The electrolytes demonstrate reversible reduction and oxidation of Mg only after being pre-treated with the dehydrating agent, magnesium borohydride, Mg[BH_4]_2, highlighting the importance of removing water in Mg based electrolytes. The addition magnesium di[bis(trifluoromethanesulfonyl)imide](Mg[TFSI]_2)(0.3 M) to N-butyl-n-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide [C4 mpyr][TFSI]/tetraglyme at a mole ratio of 1:2 showed stable CV cycling over almost 300 cycles while scanning electron microscopy(SEM) and X-ray diffraction(XRD) confirmed Mg deposition, showing non-dendritic morphology and a well-aligned growth. Further thermogravimetric analysis(TGA) demonstrated a mass retention of 79% at 250℃ for this electrolyte suggesting that the presence of the ionic liquid increases thermal stability substantially making these hybrid electrolytes compatible for RMBs.
基金supported by the National Natural Science Foundation of China(U1801255,91963210)the National Natural Science Foundation of Guangzhou,China(202201011414)。
文摘Aqueous rechargeable zinc-based batteries have attracted increasing interest and been considered potential alternatives for state-of-the-art lithium-ion batteries because of the low cost and high safety.Many cathode materials have been gradually developed and demonstrated excellent electrochemical performances.However,the complex electrochemistry,inevitable hydrogen release,and zinc corrosion severely hinder the practical application.The most concerned Zn-MnO_(2)batteries still suffer from the Mn dissolution and formation of byproducts.By adding organic solvents to inhibit the activity of water molecules,the hydrous organic electrolytes provide a sound solution for eliminating the unfavorable factors.Here we report a tetraethylene glycol dimethyl ether-based hydrous organic electrolyte consisting of LiClO_(4)·3H_(2)O and Zn(ClO4)2·6H2O,and a birnessite-type MnO_(2)cathode material for Zn-MnO_(2)batteries.The Li+/Zn2+ions co-(de)insertion mechanism is ascertained by the structural and morphological analyses.The electrostatic interaction between inserted ions and crystal structure is reduced effectively by employment of monovalent Li+ions,which ensures structural stability of cathode materials.Hydrous tetraglyme electrolyte inhibits the activity of water molecules and thus avoids the formation of byproduct Zn_(4)ClO_(4)(OH)7·Meanwhile,highly stable Zn plating/stripping for over 1500 h,an average coulombic efficiency of>99%in long-term cycling,and ultralong storage life(the cells can work well after stored over 1 year)are simultaneously realized in the novel electrolyte.Benefitting from these aspects,the Zn-MnO_(2)batteries manifest high specific capacity of 132 mA h g^(-1),an operating voltage of 1.25 V,and a capacity retention of>98%after 1000 cycles at a current density of 200 mA g^(-1).
