NaVPO4F with high cycling stability as a promising cathode for sodium-ion battery
NaVPO4F with high cycling stability as a promising cathode for sodium-ion battery
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DOI：
10.1016/j.ensm.2017.08.007
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发表时间：
2018-01-01
影响因子：
20.4
通讯作者：
Balaya, Palani
中科院分区：
文献类型：
--
作者：
Law, Markas;Balaya, Palani
本文报道了一种高性能的钠离子电池正极材料NaVPO4F的合成方法，即NaVPO4F。比较了以V_2O_3和V_2O_5为起始原料合成的NaVPO4F材料的物理和电化学性能。FESEM照片显示，样品由尺寸在200-800 nm之间的颗粒组成。用V2O5循环与金属钠在0.1C下合成的NaVPO4F的放电容量为133mAhg(-1)，平坦的放电平台为3.33V，在1C的中等电流倍率下，其可逆放电容量仍达到121mAhg(-1)，2500次循环后仍保持初始容量的82%。值得注意的是，这种电极材料在高倍率下表现出令人印象深刻的长期循环性能，即使在10,000次10和20℃循环后，它仍然能够保持81%和77%的初始放电容量。使用V2O5前驱体的NaVPO4F的持久性能归因于良好的电极表面完整性，FESEM实验证实，由于体积变化可以忽略不计。
In this article, we report a high-performing fluorophosphate-based cathode material for sodium-ion battery, namely NaVPO4F, synthesised by a facile one-step soft template method. We compared physical and electrochemical properties between the NaVPO4F materials synthesised using V2O3 and V2O5 as starting precursors. FESEM images show that the samples consist of particles of size in the range 200-800 nm. The synthesised NaVPO4F using V2O5 cycled vs. sodium metal at 0.1 C is able to deliver a high discharge capacity of 133 mAh g(-1), with a flat discharge plateau at 3.33 V. At a moderate current rate of 1 C, it still manages to achieve a reversible discharge capacity of 121 mAh g(-1,) and retains 82% of its initial capacity after 2500 cycles. Notably, this electrode material exhibits impressive long-term cyclability at high rates, where it is able to retain 81 and 77% of respective initial discharge capacities even after 10,000 cycles at 10 and 20 C. This durable performance of NaVPO4F using V2O5 precursor is attributed to the good electrode surface integrity owing to negligible volume changes as confirmed by FESEM experiment.