电荷补偿赋予K0.16Na0.05(NH4)0.71V4O10-x·0.63H2O阴极具有可调节的网格变压,以提供高效的Zn2+存储
Xueke Zhu1, Dong Fang1, Lang Zhang1
1Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, P. R. China. fangdong@kmust.edu.cn.
Dalton transactions (Cambridge, England : 2003)
|August 5, 2025
概括
这项研究引入了一种新型的正极材料,K$_{0.16}$Na$_{0.05}$(NH$_{4}$) $_{0.71}$V$_{4}$O$_{10-x}$·0.63H$_{2}$O (NaKNVOH),增强水性离子电池 (AZIB) 的结构稳定性和离子储存.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 储能 储能 储能 储能 储能 储能
背景情况:
- 瓦纳酸盐 (NH$_{4}$V$_{4}$O$_{10}$) 阴极在水性离子电池 (AZIB) 中面临挑战,原因是结构稳定性不佳和离子迁移不良,这是循环过程中晶格应变造成的.
- 开发稳定高效的阴极材料对于推进AZIB技术至关重要.
研究的目的:
- 设计一种强大的正极材料,克服AZIB中的NH$_{4}$V$_{4}$O$_{10}$的局限性.
- 提高结构完整性,促进高效的离子运输,以提高电池性能.
主要方法:
- 一个新的K$^{+}$,Na$^{+}$和NH$_{4}^{+}$联合合的瓦纳酸盐阴极 (NaKNVOH) 的合成.
- 实验性表征和密度函数理论 (DFT) 计算,以调查结构性质和离子迁移机制.
- 在AZIB中对NaKNVOH阴极进行电化学测试.
主要成果:
- NaKNVOH阴极表现出增强的结构稳定性和增加Zn$^{2+}$迁移的活性位点,这是由于Na$^{+}$和K$^{+}$离子的电荷补偿.
- 结构主导的电荷补偿有效地缓解了长时间循环期间的格子应变积累.
- 在0.5A g$^{-1}$达到495.4 mAh g$^{-1}$的高特异容量,在4A g$^{-1}$达到优异的速率能力 (177.8 mAh g$^{-1}$在4A g$^{-1}$),以及卓越的循环稳定性 (在0.5A g$^{-1}$300个循环后94.2%的保留率,在4A g$^{-1}$2000个循环后96.57%的保留率).
结论:
- 通过解决结构不稳定性和离子运输限制,NaKNVOH阴极为稳定和高性能AZIB提供了一个有前途的解决方案.
- 与金属离子联合剂是一种有效的策略,可以提高基于瓦纳的阴极的电化学性能.
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