Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education; College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang, China.
Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, Heilongjiang, China.
Nanoscale. 2017 Mar 23;9(12):4183-4190. doi: 10.1039/c7nr00793k.
The development of aqueous rechargeable sodium batteries (ARSBs) demands high-performance electrode materials, especially anode materials with low operating potential and competent electrochemical properties. The lithium/sodium vanadium phosphate family with good structural stability and abundant vanadium chemistry versatility is a promising series for energy storage applications. Herein, a new member in the sodium vanadium phosphate family, i.e. NaV(PO), is introduced as a novel anode candidate for ARSBs. For the first time, its sodium intercalation mechanism in an aqueous electrolyte is explored, and moreover, the well-aligned NaV(PO)@porous carbon nanofiber is constructed to fulfil its full potential. Based on the reversible phase transformation and 3D open framework, the NaV(PO) is demonstrated to be reliable in the aqueous electrolyte. Favored by the well-aligned, highly porous and hierarchical 1D nanoarchitecture, the freestanding aligned NaV(PO)@porous carbon hybrid film achieves fast electron/ion transport capability and good mechanical flexibility, resulting in its superior high-rate properties and excellent cycling durability. Moreover, a full cell is fabricated using the aligned NaV(PO)@C nanofiber as the anode and NaMnO as the cathode. The cell is capable of high-rate long-term cycling, which retains 84% of the capacity after five hundred cycles at alternate 20 and 5C. Therefore, this work not only demonstrates a novel high-performance anode material for ARSBs, but also introduces a general applicable and highly efficient architecture of aligned 1D nanofibers for energy storage applications.
水系可充电钠电池（ARSBs）的发展需要高性能的电极材料，特别是具有低工作电位和良好电化学性能的阳极材料。具有良好结构稳定性和丰富钒化学多功能性的锂/钠钒磷酸盐系列是储能应用的有前途的系列。在此，引入了一种新的钠钒磷酸盐家族成员，即 NaV(PO)，作为 ARSBs 的新型阳极候选材料。首次探索了其在水系电解液中的钠离子嵌入机制，并且构建了排列整齐的 NaV(PO)@多孔碳纳米纤维以充分发挥其潜力。基于可逆的相转变和 3D 开放框架，NaV(PO)在水系电解液中被证明是可靠的。得益于排列整齐、高度多孔和分级的 1D 纳米结构，独立的排列整齐的 NaV(PO)@多孔碳混合薄膜实现了快速的电子/离子传输能力和良好的机械柔韧性，从而具有出色的高倍率性能和优异的循环耐久性。此外，使用排列整齐的 NaV(PO)@C 纳米纤维作为阳极和 NaMnO 作为阴极构建了全电池。该电池能够进行高速率长期循环，在交替的 20 和 5C 下经过五百次循环后，容量保留了 84%。因此，这项工作不仅展示了一种用于 ARSBs 的新型高性能阳极材料，而且还介绍了一种通用且高效的排列 1D 纳米纤维结构，可用于储能应用。
