对苯二甲酸添加剂对锌离子电池γ-MnO2正极的影响

Study on effects of terephthalic acid additives on γ-MnO2 cathode for zinc-ion batteries

以对苯二甲酸(H2BDC)作为锌离子电池正极安全添加剂,在γ-MnO2正极材料中分别掺入了质量分数为5%、10%、20%三种不同配比的H2BDC添加剂。通过CV测试和恒流充放电测试,研究了三种不同质量配比的添加剂对电池电化学性能的影响。结果表明添加10%(质量分数)的H2BDC电池循环性能最佳。通过SEM、XRD和原位pH测试等手段进一步研究了添加剂的作用机制,结果表明H2BDC添加剂能缓冲放电过程中电解液pH的剧烈升高,抑制电极表面碱式硫酸锌杂质的产生,使电池展现出优异的循环稳定性。

Terephthalic acid(H2BDC) was used as cathode safety additives in zinc-ion battery.H2BDC additives with mass ratio of 5%,10% and 20% were added into γ-MnO2 cathode material,respectively.The effects of different mass ratio additives on the electrochemical performance of the battery were carefully studied by CV test and galvanostatic charge-discharge techniques.The results show that H2BDC additives with 10% mass ratio exhibit the best cycle performance.SEM,XRD and in-situ pH test were carried out to investigate the mechanism of H2BDC additives.The results confirm that H2BDC can release the sharp increase of pH in electrolyte during the discharge process and inhibit the generation of basic zinc sulfate impurities on the electrode surface.Therefore,zinc-ion battery with excellent cycle stability is realized.