The Li3V2(PO4)3@C materials prepared by freeze-drying assisted sol-gel method for an aqueous zinc ion hybrid battery
The Li3V2(PO4)3@C materials prepared by freeze-drying assisted sol-gel method for an aqueous zinc ion hybrid battery
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冻干辅助溶胶-凝胶法制备Li3V2(PO4)3@C材料用于水性锌离子混合电池
DOI：
10.1016/j.jelechem.2021.115685
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发表时间：
2021-09-21
影响因子：
4.5
通讯作者：
Xiong, Lizhi
中科院分区：
文献类型：
--
作者：
Jiang, Youliang;Zou, Qiulin;Xiong, Lizhi
为了获得优异的电化学性能，本文研究了水溶液锌离子混合电池（AZHBs）中电极材料内部离子和电子的快速传递问题。采用冷冻干燥辅助溶胶-凝胶法成功制备了Li 3V 2（PO 4）3@C（LVP@C）复合材料，研究了碳含量对LVP@C复合材料结构、形貌和电化学性能的影响。XRD结果表明，产物为理想的单斜结构LVP，并证实了充放电过程中Li+嵌入和脱嵌的结构变化。特别地，LVP@C-05样品表现出优异的结晶度。SEM图像显示，随着碳含量的增加，颗粒尺寸变小，颗粒分布更加均匀和分散。特别是LVP@C-05样品具有最小和最均匀的分散颗粒。充放电结果表明，在2C电流密度下，LVP@C-05样品的初始容量最高为95 mAh g-1，50次循环后的容量保持率为91%。即使在20 C电流密度下，LVP@C-05也显示出高达67 mAh g-1的有吸引力的放电容量。CV结果表明，与LVP@C-0、LVP@C-03、LVP@C-07样品的值相比，LVP @C-05样品的离子扩散系数最高（2.59 × 10 -12 cm 2 s-1）。此外，EIS和Nyquist图拟合结果表明，LVP@C-05样品的Rct最低（189.5 Ω），表明电荷转移电阻较低，反应动力学增强。
In this paper, fast ion and electron delivery inside electrode materials, which is very crucial to the aqueous zincion hybrid batteries (AZHBs), has been studied in order to achieve the excellent electrochemical performance. The Li3V2(PO4)3@C (LVP@C) composites were successfully fabricated by freeze-drying assisted sol-gel method, and the effects of carbon content on the structure, morphology and electrochemical performance of LVP@C composites were investigated. XRD results suggested that the products were made up of an ideal monoclinic structure of LVP, and the structural changes of Li+ intercalation and de-intercalation during charge-discharge process were verified. Particularly, the LVP@C-05 sample exhibits excellent crystallinity. SEM images presented that with the increase of carbon content, the size of particles is smaller, and the distribution of particles is more uniform and dispersed. Especially, the LVP@C-05 sample has the smallest and the most uniform dispersed particles. The charging-discharging results indicated that the LVP@C-05 sample delivers the highest initial capacity of 95mAh g-1 at the current density of 2C, and the capacity retention after 50th cycles is 91%. Even at 20C current density, the LVP@C-05 also shows an attractive discharge capacity as high as 67mAh g-1. CV results presented that the ionic diffusion coefficient of the LVP@C-05 sample is the highest (2.59x10-12 cm2 s-1), compared to the value of LVP@C-0, LVP@C-03, LVP@C-07 sample. Besides, EIS and Nyquist plots fitting results indicated that the Rct of LVP@C-05 sample is the lowest (189.5 omega), showing a lower charge transfer resistance and increasing the kinetics of the reaction.