Water-Stabilized Vanadyl Phosphate Monohydrate Ultrathin Nanosheets toward High Voltage Al-Ion Batteries.
Water-Stabilized Vanadyl Phosphate Monohydrate Ultrathin Nanosheets toward High Voltage Al-Ion Batteries.
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DOI：
10.1002/smll.202207619
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发表时间：
2023-02
期刊：
影响因子：
13.3
通讯作者：
Jiening Zheng;T. Xu;Guanglin Xia;Wenfeng Cui;Yaxiong Yang;Xuebin Yu
中科院分区：
文献类型：
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作者：
Jiening Zheng;T. Xu;Guanglin Xia;Wenfeng Cui;Yaxiong Yang;Xuebin Yu
铝离子电池（AIBs）因其高容量、低成本和高安全性而备受关注。然而，Al3+与基体晶格之间的强静电相互作用导致循环寿命不长，倍率性能较差。本文报道了一种利用含有voo4·H2 O的水分子通过水的电荷屏蔽效应促进Al3+迁移的新策略。结果表明，具有水润滑作用和较小位阻的VOPO4·H2 O具有高容量和快速的Al3+扩散，而循环过程中不稳定水的损失导致性能迅速下降。为了解决这一问题，利用VOPO4·H2 O与MXene之间形成的Ti - _ - O - _ - V键制备了超薄VOPO4·H2 O@MXene纳米片。MXene辅助剥离导致H2 O和VOPO4之间的V - Owater结合强度增强，使所获得的复合材料具有很强的持水能力，有助于实现非凡的循环稳定性。因此，在电流密度分别为0.5和1.0 a g-1的情况下，voo4·H2 O@MXene在420和2000次循环后可提供1.8 V的高放电电位，并保持410和374.8 mAh g-1的放电容量。这项工作为含水AIBs阴极提供了新的认识，并对高性能AIBs的开发具有重要的指导意义。
Al ion batteries (AIBs) are attracting considerable attention owing to high volumetric capacity, low cost, and high safety. However, the strong electrostatic interaction between Al3+ and host lattice leads to discontented cycling life and inferior rate capability. Herein, a new strategy of employing water molecules contained VOPO4 ·H2 O to boost Al3+ migration via the charge shielding effect of water is reported. It is revealed that VOPO4 ·H2 O with water lubrication effect and smaller steric hindrance owns high capacity and fast Al3+ diffusion, while the loss of unstable water upon cycling leads to a rapid performance degradation. To address this problem, ultrathin VOPO4 ·H2 O@MXene nanosheets are fabricated via the formed TiOV bond between VOPO4 ·H2 O and MXene. The MXene aided exfoliation results in enhanced VOwater bond strength between H2 O and VOPO4 that endows the obtained composite with strong water holding ability, contributing to the extraordinary cycling stability. Consequently, the VOPO4 ·H2 O@MXene delivers a high discharge potential of 1.8 V and maintains discharge capacities of 410 and 374.8 mAh g-1 after 420 and 2000 cycles at the current densities of 0.5 and 1.0 A g-1 , respectively. This work provides a new understanding of water-contained AIBs cathodes and vital guidance for developing high-performance AIBs.