Interstratification-assembled 2D black phosphorene and V2CTx MXene as superior anodes for boosting potassium-ion storage,Journal of Materials Chemistry A

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Interstratification-assembled 2D black phosphorene and V2CTx MXene as superior anodes for boosting potassium-ion storage
Journal of Materials Chemistry A ( IF 10.7 ) Pub Date : 2020-06-06 , DOI: 10.1039/d0ta04506c
Xinming Wu _{1,

2,

3,

4} , Han Wang _{1,

2,

3,

4} , Zhilin Zhao _{1,

2,

3,

4} , Bin Huang _{1,

2,

3,

4}

Affiliation

Although potassium-ion batteries have been widely studied because of their low cost and high theoretical capacity, the origin of the poor potassium-ion storage kinetics and low structural stability still remains elusive mainly due to the large size of K⁺ (0.138 nm). Herein, we report an interstratification-assembly strategy via van der Waals interactions to design a novel BPE@V₂CT_x hybrid anode, wherein black phosphorene (BPE) and V₂CT_x MXene are derived from their individual 2D nanosheets. The coupled BPE@V₂CT_x hybrid anode with a 2D stacked interstratification structure and large specific surface area could efficiently take advantage of BPE and V₂CT_x nanosheets and create more active sites. This interstratification hybrid electrode not only provides an enlarged interlayer spacing and a three-dimensional interconnected conductive network to accelerate the K⁺ transport rates, but also has good tolerance to volume changes caused by phase transformations during the fast potassiation/depotassiation process. DFT calculations further confirm that potassium affinities and diffusion kinetics are significantly enhanced in the BPE@V₂CT_x hybrid anode, particularly in BPE@V₂CF₂. As a result, the hybrid anode possesses a remarkable synergetic effect and achieves a high reversible capacity of 593.6 mA h g⁻¹ at 0.1 A g⁻¹ and excellent cycling stability of 485/261 mA h g⁻¹ with 91/86% capacity retention after 3000 cycles at 0.2/2.0 A g⁻¹. This work opens a new way for the application of self-assembled hybrid electrodes in energy storage, electrocatalysis and sensors.

中文翻译：

层间组装的2D黑色磷光体和V2CTx MXene作为增强钾离子存储的优异阳极

尽管由于钾离子电池的低成本和高理论容量已对其进行了广泛的研究，但主要由于K ^+的尺寸较大（0.138 nm），钾离子存储动力学差和结构稳定性差的原因仍然难以捉摸。在本文中，我们报告了通过范德华相互作用的互层组装策略，以设计新颖的BPE @ V ₂ CT _x杂化阳极，其中黑色磷烯（BPE）和V ₂ CT _x MXene源自其各自的2D纳米片。耦合的BPE @ V ₂ CT _x具有2D堆叠层间结构和大比表面积的混合阳极可以有效利用BPE和V ₂ CT _x纳米片的优势，并产生更多的活性位点。这种层间混合电极不仅提供了更大的层间间距和三维互连的导电网络以加速K ⁺传输速率，而且对快速钾化/去钾化过程中由相变引起的体积变化具有良好的耐受性。DFT计算进一步证实，在BPE @ V ₂ CT _x混合阳极中，特别是在BPE @ V ₂ CF _2中，钾亲和力和扩散动力学得到显着增强。。结果，该混合阳极具有显着的协同作用，并在0.1 A g ^-1时实现了593.6 mA hg ^-1的高可逆容量，在485/261 mA hg ^-1时具有出色的循环稳定性，并保持了91/86％的容量在0.2 / 2.0 A g ^-1下进行3000次循环。这项工作为自组装混合电极在储能，电催化和传感器中的应用开辟了一条新途径。

更新日期：2020-06-30

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