通过高频 Na+ 激活稳定的多电子转移跳跃到一个 Sc-doped Na3.97VMn0.97Sc0.03(PO4) 3
Hui Gao1,2, Cheng Peng2, Rui Xu2
1School of Materials Science and Engineering, Dalian Jiaotong University, Dalian, 116028, China.
Small (Weinheim an der Bergstrasse, Germany)
|August 14, 2025
概括
兴奋剂通过激活多电子转移和改善动力学来提高离子电池阴极容量. 这种修改提高了下一代储能系统的性能和稳定性.
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:
- 离子电池 (SIB) 对储能充满希望,但正极容量限制阻碍了它们的广泛采用.
- Na4VMn(PO4) 3 (NVMP) 阴极显示出潜力,但在其原生V3+/V4+和Mn2+/Mn3+氧化还原对中遭受缓慢动力学的影响.
- 激活像V4+/V5+这样的更高价值状态可以增加容量,但通常需要高潜力 (>4.0 V vs Na+/Na),并导致结构不稳定.
研究的目的:
- 设计一个修改后的NVMP阴极,激活多电子转移以获得更高的容量.
- 为了增强电化学动力学和改善在稳定的电压范围内的氧化还原反应的可逆性.
- 调查兴奋剂在改善Na+扩散和循环稳定性方面的作用.
主要方法:
- 合成与 (Sc) 合的Na3.97VMn0.97Sc0.03(PO4) 3材料.
- 电化学表征包括循环电压测量和静电循环来评估容量和动力学.
- 在循环过程中分析Na+扩散机制和结构稳定性.
主要成果:
- 通过启用2.05电子传输,sc-doped NVMP实现了16.7%的容量增加,达到113.8 mAh g-1.
- V3+/V4+和Mn2+/Mn3+的氧化还原反应在2.0-3.8V范围内加速,改善了动力学.
- 由于Sc诱导的VNa'空缺,增强的Na+扩散动力学导致了优异的容量保留 (80.2%在5C下1400个循环后).
结论:
- 兴奋剂有效地激活了NVMP阴极中的多电子转移,同时保持了结构完整性.
- 该策略提供了合理的电压窗口,减轻了与高潜力氧化还原对相关的可逆性问题.
- 这项工作为SIBs开发高性能,稳定的多电子转移阴极提供了一种可行的方法.
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