对苯二甲酸镁作为钠离子电池的有机负极材料

报道了对苯二甲酸镁作为钠离子电池负极材料的研究.以对苯二甲酸和氢氧化镁为原料,采用酸碱中和反应制备了含结晶水的对苯二甲酸镁(MgC8H4O4·2H2O),该材料对钠离子电池表现出了较好的电化学活性、优异的倍率性能以及良好的循环稳定性.在0.5C(1C=300 mA·g-1)倍率下循环50周以后,可逆容量由114mAh·g-1降至95 mAh·g-1,容量保持率高达83%;在2C的倍率下有高达90 mAh·g-1的可逆比容量.另外,在氮气气氛中,400℃进行后续热处理得到了不含结晶水的对苯二甲酸镁(MgC8H4O4),探讨了结晶水对其电化学性能的影响.结果表明,MgC8H4O4·2H2O的比容量、倍率性能以及循环稳定性都明显优于不含结晶水的对苯二甲酸镁.

Magnesium Terephthalate as an Organic Anode Material for Sodium Ion Batteries

In this study, the electrochemical properties of magnesium terephthalate with hydration water (MgC₈H₄O₄·2H₂O) as an anode material for sodium ion batteries were investigated for the first time. MgC₈H₄O₄· 2H₂O was synthesized via a facile neutralization method using terephthalic acid (C₈H₆O₄) and magnesium hydroxide (Mg(OH)₂) as precursors. Good cycle performance was obtained as 114 mAh·g^-1 was found for the second cycle and 95 mAh·g^-1 was obtained after 50 cycles at a current rate of 0.5C (1C=300 mA·g^-1), giving a capacity retention of 84%. At a current rate of 2C, it presents a discharge capacity of 90 mAh·g^-1. After heating under a nitrogen atmosphere at 400 ℃, anhydrous magnesium terephthalate (MgC₈H₄O₄) was obtained. The effect of hydration water on the crystal structure, morphology, and electrochemical properties was investigated. The results indicate that the specific discharge capacity, rate capacity, and cyclic performance of MgC₈H₄O₄· 2H₂O are better than those of MgC₈H₄O₄.