Yao J H, Li Y W, Song X B, Zhang Y F, Yan J
Guangxi Key Laboratory of Electrochemical and Magneto-Chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, China.
J Nanosci Nanotechnol. 2018 May 1;18(5):3599-3605. doi: 10.1166/jnn.2018.14684.
The ZnFe2O4 samples with the triblock copolymer P123 (P123) additive quantity of 0 wt.%, 2 wt.%, 5 wt.%, 8 wt.% and 10 wt.% were prepared by a very facile homogeneous precipitation method followed by high temperature sintering. The microstructures of the prepared samples were analyzed by X-ray diffraction (XRD) and Field emission scanning electron microscopy (FESEM). The results revealed that the five prepared samples are all normal spinel zinc ferrite (ZnFe2O4); the sample with the P123 additive quantity of 8 wt.% has the smallest particle size among the five samples. The lithium storage performances of the prepared samples are characterized by cyclic voltammograms (CV), electrochemical impedance spectroscopy (EIS), and charge-discharge tests. The results demonstrated that adding proper amount of P123 can obviously improve the lithium storage performances of zinc ferrite spinel powder. But excessive P123 can induce the particle agglomerates so that the lithium storage performance of sample decays significantly. The ZnFe2O4 sample with the P123 additive quantity of 8 wt.% exhibited the highest electrochemical activity, the best rate performance, and superior cycling stability. For example, after 50 charge/discharge cycles under a current density of 120 mA g-1, the ZnFe2O4 sample with the P123 additive quantity of 8 wt.% can retain a specific discharge capacity of 468 mAh g-1, much higher than that of for the ZnFe2O4 sample with the P123 additive quantity of 0 wt.% (224 mAh g-1).
采用非常简便的均匀沉淀法并结合高温烧结制备了三嵌段共聚物P123添加量分别为0 wt.%、2 wt.%、5 wt.%、8 wt.%和10 wt.%的ZnFe₂O₄样品。通过X射线衍射（XRD）和场发射扫描电子显微镜（FESEM）对制备样品的微观结构进行了分析。结果表明，所制备的五个样品均为正常尖晶石型铁酸锌（ZnFe₂O₄）；P123添加量为8 wt.%的样品在五个样品中粒径最小。通过循环伏安法（CV）、电化学阻抗谱（EIS）和充放电测试对制备样品的储锂性能进行了表征。结果表明，添加适量的P123可明显提高铁酸锌尖晶石粉末的储锂性能。但过量的P123会导致颗粒团聚，从而使样品的储锂性能显著下降。P123添加量为8 wt.%的ZnFe₂O₄样品表现出最高的电化学活性、最佳的倍率性能和优异的循环稳定性。例如，在120 mA g⁻¹的电流密度下进行50次充放电循环后，P123添加量为8 wt.%的ZnFe₂O₄样品可保持468 mAh g⁻¹的比放电容量，远高于P123添加量为0 wt.%的ZnFe₂O₄样品（224 mAh g⁻¹）。
