Chlorination roasting followed by water leaching process was used to extract lithium from lepidolite.The microstructure of the lepidolite and roasted materials were characterized by X-ray diffraction（XRD）.Various pa...Chlorination roasting followed by water leaching process was used to extract lithium from lepidolite.The microstructure of the lepidolite and roasted materials were characterized by X-ray diffraction（XRD）.Various parameters including chlorination roasting temperature,time,type and amount of chlorinating agents were optimized.The conditional experiments indicate that the best mass ratio of lepidolite to NaCl to CaCl2 is 1：0.6：0.4 during the roasting process.The extraction of lithium reaches peak value of 92.86% at 880 °C,potassium,rubidium,and cesium 88.49%,93.60% and 93.01%,respectively.The XRD result indicates that the major phases of the product after roasting lepidolite with mixture of chlorinating agents（CaCl2 and NaCl） are SiO2,CaF2,KCl,CaSiO3,CaAl2Si2O8,NaCl and NaAlSi3O8.展开更多
Spherical and homogeneously mixed metal hydroxide Ni0.8Co0.1Mn0.1（OH）2 precursor was successfully synthesized by co-precipitation method in a simple and small vessel with the volume of 1L.The conditions of synthetic...Spherical and homogeneously mixed metal hydroxide Ni0.8Co0.1Mn0.1（OH）2 precursor was successfully synthesized by co-precipitation method in a simple and small vessel with the volume of 1L.The conditions of synthetic process including amount of chelating agent,stirring speed and temperature were studied.LiNi0.8Co0.1Mn0.1O2 samples were obtained by calcinating the precursors.The crystal structure,morphology and electrochemical properties were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,charge-discharge test,AC impedance and cyclic voltammetry.In the voltage range of 2.8-4.3 V,the initial discharge capacities of LiNi0.8Co0.1Mn0.1O2 at 0.1C and 1C rates were 199 and 170 mA·h/g,respectively.After 80 cycles at 1C,the discharge capacity retention was 92%,suggesting its promising application as the cathode material for Li-ion batteries.展开更多
The P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2)materials were synthesized by an ultrasonic spray pyrolysis followed by solid-state sintering method.The structures,morphologies and electrochemical performances of Na_(2/3)Fe_...The P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2)materials were synthesized by an ultrasonic spray pyrolysis followed by solid-state sintering method.The structures,morphologies and electrochemical performances of Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2)materials were characterized thoroughly by means of X-ray diffractometer,scanning electron microscope and electrochemical charge/discharge instruments.Moreover,a thin layer of Al_(2)O_(3),which was formed on the surface of Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2),can enhance the storage performance by preventing the formation of Na_(2)CO_(3)·H_(2)O,which is believed to enhance the electrochemical performances of Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2)materials.This facile surface modification method may pave a way to synthesize advanced cathode materials for sodium-ion batteries.展开更多
Lithium(Li)metal has the lowest standard electrochemical redox potential and very high theoretical specific capacity,making it the most potential anode material for rechargeable batteries[1].The use of Li metal in org...Lithium(Li)metal has the lowest standard electrochemical redox potential and very high theoretical specific capacity,making it the most potential anode material for rechargeable batteries[1].The use of Li metal in organic liquid electrolyte faces many issues in terms of battery performance and safety[2].Solid-electrolyte in-terphase(SEI)formation during the uneven Li deposition will continuously consume Li and dry up the electrolyte.Solid-state electrolytes are superior to liquid counterparts in terms of battery safety due to their nonflammable nature[3].展开更多
Nano-La2O3 was modified with the vinyltrimethoxylsilane by hydrolysis and a novel poly （vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） based composite polymer electrolyte doped with the modified nano-La2O3...Nano-La2O3 was modified with the vinyltrimethoxylsilane by hydrolysis and a novel poly （vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） based composite polymer electrolyte doped with the modified nano-La2O3 was prepared by phase inversion method. The physicochemical properties were studied by SEM, FT-IR, XRD, TG and electrochemical methods. The results of FT-IR indicated that the nano-La2O3 was successfully modified with vinyltrimethoxylsilane. The XRD analysis showed that the incorporation of modified nano-La2O3 into the polymer electrolyte membranes could effectively reduce the crystallinity of PVDF-HFP, and the characterizations also suggested that thermal stability and electrochemical stability window could reach to 382°C and 5.1V, respectively; the reciprocal temperature dependence of ionic conductivity followed Vogel-Tamman-Fulcher （VTF） relation, ionic conductivity at room temperature was up to 3.5×10-3S/cm and lithium ions transference number was up to 0.42; the interfacial resistance increased at initial value about353Ω/cm2 and reached a steady value about 559Ω/cm2 after 5d storage at 30°C. The fabricated Li/As-prepared electrolytes/LiCoO2 coin cell showed excellent rate and cycle performances.展开更多
基金Project(2011FJ1005)supported by Science and Technology Major Projects of Hunan Province,ChinaProject supported by Hunan Provincial Innovation Foundation for Postgraduate,China
文摘Chlorination roasting followed by water leaching process was used to extract lithium from lepidolite.The microstructure of the lepidolite and roasted materials were characterized by X-ray diffraction（XRD）.Various parameters including chlorination roasting temperature,time,type and amount of chlorinating agents were optimized.The conditional experiments indicate that the best mass ratio of lepidolite to NaCl to CaCl2 is 1：0.6：0.4 during the roasting process.The extraction of lithium reaches peak value of 92.86% at 880 °C,potassium,rubidium,and cesium 88.49%,93.60% and 93.01%,respectively.The XRD result indicates that the major phases of the product after roasting lepidolite with mixture of chlorinating agents（CaCl2 and NaCl） are SiO2,CaF2,KCl,CaSiO3,CaAl2Si2O8,NaCl and NaAlSi3O8.
基金Project(2014CB643406)supported by the National Basic Research Program of China
文摘Spherical and homogeneously mixed metal hydroxide Ni0.8Co0.1Mn0.1（OH）2 precursor was successfully synthesized by co-precipitation method in a simple and small vessel with the volume of 1L.The conditions of synthetic process including amount of chelating agent,stirring speed and temperature were studied.LiNi0.8Co0.1Mn0.1O2 samples were obtained by calcinating the precursors.The crystal structure,morphology and electrochemical properties were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,charge-discharge test,AC impedance and cyclic voltammetry.In the voltage range of 2.8-4.3 V,the initial discharge capacities of LiNi0.8Co0.1Mn0.1O2 at 0.1C and 1C rates were 199 and 170 mA·h/g,respectively.After 80 cycles at 1C,the discharge capacity retention was 92%,suggesting its promising application as the cathode material for Li-ion batteries.
基金financially supported by the Natural Science Foundation of Hunan Province,China(No.2020JJ5755)the National Natural Science Foundation of China(Nos.51804344,51704332,51874360)the Innovation and Entrepreneurship Project of Hunan Province,China(No.2018GK5026)。
文摘The P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2)materials were synthesized by an ultrasonic spray pyrolysis followed by solid-state sintering method.The structures,morphologies and electrochemical performances of Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2)materials were characterized thoroughly by means of X-ray diffractometer,scanning electron microscope and electrochemical charge/discharge instruments.Moreover,a thin layer of Al_(2)O_(3),which was formed on the surface of Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2),can enhance the storage performance by preventing the formation of Na_(2)CO_(3)·H_(2)O,which is believed to enhance the electrochemical performances of Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2)materials.This facile surface modification method may pave a way to synthesize advanced cathode materials for sodium-ion batteries.
文摘Lithium(Li)metal has the lowest standard electrochemical redox potential and very high theoretical specific capacity,making it the most potential anode material for rechargeable batteries[1].The use of Li metal in organic liquid electrolyte faces many issues in terms of battery performance and safety[2].Solid-electrolyte in-terphase(SEI)formation during the uneven Li deposition will continuously consume Li and dry up the electrolyte.Solid-state electrolytes are superior to liquid counterparts in terms of battery safety due to their nonflammable nature[3].
基金Project supported by Major Provincial Science and Technology Programs of Hunan (2011FJ1005)Central College on the 2010 Operational Costs of Basic Research Project (2010QZZD0101)
文摘Nano-La2O3 was modified with the vinyltrimethoxylsilane by hydrolysis and a novel poly （vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） based composite polymer electrolyte doped with the modified nano-La2O3 was prepared by phase inversion method. The physicochemical properties were studied by SEM, FT-IR, XRD, TG and electrochemical methods. The results of FT-IR indicated that the nano-La2O3 was successfully modified with vinyltrimethoxylsilane. The XRD analysis showed that the incorporation of modified nano-La2O3 into the polymer electrolyte membranes could effectively reduce the crystallinity of PVDF-HFP, and the characterizations also suggested that thermal stability and electrochemical stability window could reach to 382°C and 5.1V, respectively; the reciprocal temperature dependence of ionic conductivity followed Vogel-Tamman-Fulcher （VTF） relation, ionic conductivity at room temperature was up to 3.5×10-3S/cm and lithium ions transference number was up to 0.42; the interfacial resistance increased at initial value about353Ω/cm2 and reached a steady value about 559Ω/cm2 after 5d storage at 30°C. The fabricated Li/As-prepared electrolytes/LiCoO2 coin cell showed excellent rate and cycle performances.
