Spinel LiMn204 was synthesized by glycine-nitrate method and coated with CaCO3 in order to enhance the electrochemical performance at room temperature （25℃） and 55℃. The uncoated and CaCO3-coated LiMn204 materials...Spinel LiMn204 was synthesized by glycine-nitrate method and coated with CaCO3 in order to enhance the electrochemical performance at room temperature （25℃） and 55℃. The uncoated and CaCO3-coated LiMn204 materials were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical tests. XRD and SEM results indicated that CaCO3 particles encapsulated the surface of the LiMn204 without causing any structural change. The charge-discharge tests showed that the specific discharge capacity fade of pristine electrode at 25 and 55℃ were 25.5% and 52%, respectively. However, surface modified cathode shows 7.4% and 29.5% loss compared to initial specific discharge capacity at 70th cycle for 25 and 55~C, respectively. The improvement of electrochemical performance is attributed to suppression of Mn2＋ dissolution into electrolyte via CaCO3 layer.展开更多
LiEr0.02Fe0.98PO4/C composite cathode was synthesized by a simple solution method with polyethylene glycol （PEG） as the reductive agent and carbon source. The effect of erbium doping on the electrochemical behavior ...LiEr0.02Fe0.98PO4/C composite cathode was synthesized by a simple solution method with polyethylene glycol （PEG） as the reductive agent and carbon source. The effect of erbium doping on the electrochemical behavior of LiFePO4 was studied in this paper. The samples were characterized by X-ray powder diffraction and scanning electron microscopy and the electrochemical properties were investigated by the charge-discharge test. An initial discharge capacity of 149 mAh.g-1 was achieved for the LiEr0.02Fe0.98PO4/C composite cathode with a rate of 0.1 C. The electronic conductivity of Er doped LiFePO4/C was measured as 10-2 S.cm-1. The results indicated that erbium doping did not destroy the lattice structure of LiFePO4 and enlarge the lattice volume. These changes are beneficial to the improvement of the electrochemical performance of the LiFePO4 cathode.展开更多
基金supported by the Erciyes University Research Found under the code of FBA-08-439
文摘Spinel LiMn204 was synthesized by glycine-nitrate method and coated with CaCO3 in order to enhance the electrochemical performance at room temperature （25℃） and 55℃. The uncoated and CaCO3-coated LiMn204 materials were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical tests. XRD and SEM results indicated that CaCO3 particles encapsulated the surface of the LiMn204 without causing any structural change. The charge-discharge tests showed that the specific discharge capacity fade of pristine electrode at 25 and 55℃ were 25.5% and 52%, respectively. However, surface modified cathode shows 7.4% and 29.5% loss compared to initial specific discharge capacity at 70th cycle for 25 and 55~C, respectively. The improvement of electrochemical performance is attributed to suppression of Mn2＋ dissolution into electrolyte via CaCO3 layer.
基金supported by the Research Foundation of Erciyes University FBA-08-440 (Kayseri, Turkey)
文摘LiEr0.02Fe0.98PO4/C composite cathode was synthesized by a simple solution method with polyethylene glycol （PEG） as the reductive agent and carbon source. The effect of erbium doping on the electrochemical behavior of LiFePO4 was studied in this paper. The samples were characterized by X-ray powder diffraction and scanning electron microscopy and the electrochemical properties were investigated by the charge-discharge test. An initial discharge capacity of 149 mAh.g-1 was achieved for the LiEr0.02Fe0.98PO4/C composite cathode with a rate of 0.1 C. The electronic conductivity of Er doped LiFePO4/C was measured as 10-2 S.cm-1. The results indicated that erbium doping did not destroy the lattice structure of LiFePO4 and enlarge the lattice volume. These changes are beneficial to the improvement of the electrochemical performance of the LiFePO4 cathode.
