标题:
钒掺杂的可充镁电池正极材料Mg1.03Mn0.97SiO4Vanadium Doped Mg1.03Mn0.97SiO4 Cathode Materials for Rechargeable Magnesium Batteries
作者:
伊丽奴尔?吐胡达洪, 努丽燕娜, 陈强, 杨军, 王久林
关键字:
可充镁电池, 正极材料, 电化学性能, 金属离子掺杂Rechargeable Magnesium Batteries; Cathode Materials; Electrochemical Performance; Metal Ion Doping
期刊名称:
《Material Sciences》, Vol.2 No.4, 2012-10-31
摘要:
采用高温固相方法制备了钒掺杂的可充镁电池正极材料Mg1.03–0.5xMn0.97–xVxSiO4(x = 0、0.034、0.069和0.134)。X射线衍射(XRD)表明掺杂V后Mg1.03Mn0.97SiO4的晶体结构未发生变化。扫描电镜(SEM)显示材料颗粒粒径随V掺杂量的增加而逐渐减小。通过循环伏安、交流阻抗、恒电流充放电测试比较了掺杂前后四种材料的电化学性能。电化学结果表明，掺杂V改善了Mg1.03Mn0.97SiO4脱嵌镁的可逆性、提高了其放电容量和放电电压平台。在0.01 C倍率下，x = 0.069的Mg1.03–0.5xMn0.97–xVxSiO4放电容量可达140 mAh/g，远大于未掺杂的Mg1.03Mn0.97SiO4 (40 mAh/g)，并且1.62 V(vs. Mg)的放电平台可提高到1.65 V。
Vanadium doped Mg1.03–0.5xMn0.97–xVxSiO4 (x = 0, 0.034, 0.069 and 0.134) materials were synthesized by a high temperature solid-state method. The crystal structure and morphology were characterized by XRD and SEM measurements and the results demonstrated that V3+ ion dopant does not affect the structure of Mg1.03Mn0.97SiO4 and particle size decreases with increasing vanadium amount. Furthermore, the electrochemical performance of Mg1.03–0.5xMn0.97–xVxSiO4 materials as rechargeable magnesium battery cathodes was compared by cyclic voltammetry, AC impedance and direct current charge-discharge techniques. The vanadium doped materials exhibit improved electrochemical performance with lower polarization for magnesium de-intercalation and intercalation, larger discharge capacity and higher discharge flat plateau compared with that of pure Mg1.03Mn0.97SiO4. At a rate of 0.01 C(3.14 mA/g), 140 mAh/g discharge capacity and 1.65 V (vs. Mg) discharge voltage plateau can be reached for Mg1.03–0.5xMn0.97–xVxSiO4 with x = 0.069, compared with 40 mAh/g discharge capacity and 1.62 V (vs. Mg) discharge voltage plateau for pure Mg1.03Mn0.97SiO4.