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以葡萄糖为主碳源,抗坏血酸(AA)为辅助碳源,采用固相法合成了倍率性能优良的碳包覆磷酸钒锂(LVP/C-AA)复合正极材料。通过X射线衍射(XRD)仪、扫描电镜(SEM)、透射电镜(TEM)、拉曼光谱(Raman)、恒电流充放电测试、循环伏安(CV)和交流阻抗(EIS)测试表征了材料的物相、形貌、结构和电化学性能。结果表明,添加少量的抗坏血酸为辅助碳源对Li_3V_2(PO_4)_3晶体结构没有明显的影响,但能明显提高Li_3V_2(PO_4)的高倍率性能。LVP/C-AA在5 C时的首次放电比容量可达162.4 mAh·g~(-1),100次循环后容量保持率高达80.4%。
A carbon-coated lithium vanadium phosphate (LVP / C-AA) composite cathode material with good rate performance was synthesized by solid-phase method using glucose as carbon source and ascorbic acid (AA) as secondary carbon source. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy (Raman), constant current charge and discharge test, cyclic voltammetry (CV) and alternating current impedance (EIS) The phase, morphology, structure and electrochemical properties. The results showed that the addition of a small amount of ascorbic acid as a secondary carbon source had no significant effect on the crystal structure of Li 3 V 2 (PO 4) 3 but significantly enhanced the high rate performance of Li 3 V 2 (PO 4). LVP / C-AA has a first discharge specific capacity of 162.4 mAh · g -1 at 5 C and a capacity retention of up to 80.4% after 100 cycles.