层板金属离子不同的钴基双氢氧化物制备及其电化学性能

Preparation and Electrochemical Capacitance Performance of Co-Based Layered Double Hydroxides with Different Trivalent Metal Cations

通过调变层板中的三价金属离子制备了层板金属离子不同的钴基双氢氧化物(LDHs),X-射线衍射(XRD)和傅里叶变换红外(FTIR)测试表明,层板中金属离子的变化对LDHs的物理结构有较大影响。电化学性能比较表明,三价金属离子的改变对材料的有效工作电位窗口和大电流稳定性及循环容量保持率均有很大影响。由于二价与三价金属离子在电化学过程中的作用不同,Co-AlLDHs在1A·g-1的电流密度下比容量达到447F·g-1;Co-InLDHs与Co-CrLDHs则具有很好的循环稳定性和电容性质。

Co-based layered double hydroxides（LDHs） with different metal cations in the host layers, were prepared by modulating the composition of trivalent cations. The Fourier transform infrared （FTIR） spectra and X-ray diffraction（XRD） patterns of the as-prepared samples indicate that the changes of the trivalent cations in the host layers have a great influence on the structures of the LDHs. The results of the electrochemical tests also present some differences. The different trivalent cations of Co-based LDHs have a significant impact on the effective potential work window, which also can influence the stability at large current density and capacity retention characteristic in cycle test. Due to the different roles of divalent and trivalent metal ions on the electrochemical performance, Co-Al LDHs has a specific capacitance of 447 F·g-1 at the discharge current density of 1 A·g-1; Both Co-In LDHs and Co-Cr LDHs have better cycle stability and capacitance behavior than Co-Al LDHs.