Tin - based composite oxides anode materials for lithium - ion thin - film batteries have been prepared by high - erergy ball - milling method.The phase evolution,morphology and electrochemical properties of the mater...Tin - based composite oxides anode materials for lithium - ion thin - film batteries have been prepared by high - erergy ball - milling method.The phase evolution,morphology and electrochemical properties of the materials were investigated by X - ray diffraction,scanning electron microscopy,cyclic voltammetry,charge - discharge test.The re - sults show milling can cause the stannous oxide crystal losing its crystalli ne character and becoming the amor - phous structure.The particle size of the powder materials decreases with the increase of ball - milling time.The re - versible specific capacity is more than578mAh·g -1 and its capacity loss per cycle is only0.31%after being cy - cled20times,which indicates that the material prepared by this method has go od electrochemical behavior and may be a candidate for the next generation anode materials for lithiumn ion batteries.展开更多
Carbon coated LiFePO4 cathode material was synthesized by one-step solid-state reaction and characterized by X-ray diffraction (XRD), field-emission-scanning electron microscope (FESEM). Electrochemical performances o...Carbon coated LiFePO4 cathode material was synthesized by one-step solid-state reaction and characterized by X-ray diffraction (XRD), field-emission-scanning electron microscope (FESEM). Electrochemical performances of the material as cathode in lithium-ion battery were investigated at medium and elevated temperature (30 and 55 ℃) by galvanostatic charge-discharge and A.C. impedance tests. The results show that carbon coated LiFePO4 powder exhibits a well-crystallized olivine structure and spherical morphology with an average particle size of about 500 nm. Galvanostatic charge-discharge tests show that the reversible discharge capacity at 1 C and 1.5 C rates was improved from 121 and 105 mAh·g-1 at 30 ℃ to 136 and 123 mAh·g-1 at 55℃, respectively, while the enhancement of high temperature on electrochemical performance is less obvious at a rate lower than 0.5 C. Impedance spectra analyses indicate that the cathode material has a remarkably higher lithium-ion diffusivity at 55 ℃ than that at 30 ℃, which improves the electrochemical performance at high temperature.展开更多
文摘Tin - based composite oxides anode materials for lithium - ion thin - film batteries have been prepared by high - erergy ball - milling method.The phase evolution,morphology and electrochemical properties of the materials were investigated by X - ray diffraction,scanning electron microscopy,cyclic voltammetry,charge - discharge test.The re - sults show milling can cause the stannous oxide crystal losing its crystalli ne character and becoming the amor - phous structure.The particle size of the powder materials decreases with the increase of ball - milling time.The re - versible specific capacity is more than578mAh·g -1 and its capacity loss per cycle is only0.31%after being cy - cled20times,which indicates that the material prepared by this method has go od electrochemical behavior and may be a candidate for the next generation anode materials for lithiumn ion batteries.
文摘Carbon coated LiFePO4 cathode material was synthesized by one-step solid-state reaction and characterized by X-ray diffraction (XRD), field-emission-scanning electron microscope (FESEM). Electrochemical performances of the material as cathode in lithium-ion battery were investigated at medium and elevated temperature (30 and 55 ℃) by galvanostatic charge-discharge and A.C. impedance tests. The results show that carbon coated LiFePO4 powder exhibits a well-crystallized olivine structure and spherical morphology with an average particle size of about 500 nm. Galvanostatic charge-discharge tests show that the reversible discharge capacity at 1 C and 1.5 C rates was improved from 121 and 105 mAh·g-1 at 30 ℃ to 136 and 123 mAh·g-1 at 55℃, respectively, while the enhancement of high temperature on electrochemical performance is less obvious at a rate lower than 0.5 C. Impedance spectra analyses indicate that the cathode material has a remarkably higher lithium-ion diffusivity at 55 ℃ than that at 30 ℃, which improves the electrochemical performance at high temperature.
