Effect of Crystal Structure and Morphology on Na3V2(PO4)2F3 Performances for Na‐Ion Batteries,Batteries & Supercaps

当前位置： X-MOL 学术 › Batteries Supercaps › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Effect of Crystal Structure and Morphology on Na3V2(PO4)2F3 Performances for Na‐Ion Batteries
Batteries & Supercaps ( IF 5.1 ) Pub Date : 2020-02-19 , DOI: 10.1002/batt.201900202
Ayan Mukherjee _{1,

2} , Tali Sharabani _{1,

2} , Rosy Sharma _{1,

2} , Sivan Okashy _{1,

2} , Malachi Noked _{1,

2}

Affiliation

Na‐ion batteries (SIB) are considered promising systems for energy storage devices, however diversity of available cathode materials is lower compared to lithium ion batteries. Recently, Na₃V₂(PO₄)₂F₃ (NVPF) has been demonstrated as promising cathode material for SIB owing to high specific capacity and electrochemical reversibility. However, most of reports demonstrates capacities lower than theoretical value and optimization of electrochemical performances by controlled morphology and crystal structure was not demonstrated yet. Here, we demonstrate a scalable synthesis strategy to tailor the crystal structure and morphology of NVPF and showed that our approach enables to optimize the Na⁺ ion accommodation, diffusion and stability. A flower morphology (NVPF‐F) crystalizes in tetragonal structure, demonstrates discharge capacity of 109.5 mA.h.g⁻¹ and 98.1 % columbic efficiency whereas a hollow spherical morphology (NVPF‐S) with orthorhombic structure exhibits discharge capacity of 124.8 mA.h.g⁻¹ (very close to theoretical value) and 99.5 % columbic efficiency. The observed discharge capacity for NVPF‐S is highest reported value which is ascribed due to stable crystal structure and monodispersed morphology. Long term stability with negligible capacity loss is demonstrated over 550 cycles. Our findings shed light on importance of crystal structure and morphology of NVPF on electrochemical response, and realization as cathode material for SIB.

中文翻译：

钠电池的晶体结构和形态对Na3V2（PO4）2F3性能的影响

钠离子电池（SIB）被认为是用于能量存储设备的有前途的系统，但是与锂离子电池相比，可用的阴极材料的多样性要低。最近，由于高比容量和电化学可逆性，已证明Na ₃ V ₂（PO ₄）₂ F ₃（NVPF）作为用于SIB的有希望的阴极材料。然而，大多数报告表明容量低于理论值，并且尚未证明通过受控的形态和晶体结构来优化电化学性能。在这里，我们展示了一种可扩展的合成策略，以定制NVPF的晶体结构和形态，并表明我们的方法能够优化Na ⁺离子调节，扩散和稳定性。甲花形态（NVPF-F）在四方结构crystalizes，演示的放电容量109.5 mA.hg ^-1和98.1％库仑效率而空心球形形态（NVPF-S）与124.8 mA.hg的斜方晶结构表现出放电容量^{- 1}（非常接近理论值）和99.5％的哥伦比亚效率。观察到的NVPF-S的放电容量是最高的报告值，这归因于稳定的晶体结构和单分散的形态。在550个循环中证明了长期稳定性，而容量损失可忽略不计。我们的发现揭示了NVPF的晶体结构和形态对电化学响应的重要性，以及实现为SIB的阴极材料的重要性。

更新日期：2020-02-19

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文