对于高电池性能而言,磁场诱导的脊柱氧化物失序阶段
Shuwei Sun1, Xiaoning Li2,3, Chu Zhang4
1International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, School of Physics and Electronics, Henan University, Kaifeng, 475004, China.
Advanced materials (Deerfield Beach, Fla.)
|June 27, 2024
概括
来自Fe3O4外的局部磁场在较低的温度下诱导氧化 (LNMO) 阴极的混乱阶段. 这种方法可以提高电化学性能和循环稳定性,而不会增加有害的Mn3+含量.
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
- 固态化学 固态化学
背景情况:
- 与其有序对应物相比,氧化 (LiMn1.5Ni0.5O4,LNMO) 的无序相为高压阴极提供了优越的电化学性能.
- 目前用于诱导这种无序阶段的方法通常会导致由于Mn3+含量增加而导致容量退化.
研究的目的:
- 研究使用局部磁场在较低温度下诱导LNMO中无序相变的方法.
- 通过尽量减少在相位过渡期间Mn3+含量的增加来减轻容量退化.
主要方法:
- 用磁性Fe3O4外覆盖LNMO以产生局部磁场.
- 将LNMO中的相变与Fe3O4外,非磁性Al2O3外,鞋底热处理和磁场内的热处理进行比较.
- 使用电化学表征来评估性能,循环稳定性和运动性质.
主要成果:
- 当地磁场在较低的温度下有效地诱导了LNMO在LNMO中的秩序-混乱阶段过渡.
- 磁性Fe3O4外的存在至关重要,与非磁性Al2O3外或底部热处理不同.
- 带有Fe3O4外的无序LNMO表现出卓越的循环稳定性和改进的动力特性.
- 证据表明,由磁场启动的激进对机制驱动相位过渡.
结论:
- 局部磁场可以成为一种新的工具来控制LNMO等阴极材料中的相位过渡.
- 这种方法可以形成具有增强电化学性质和降低Mn3+含量的无序LNMO.
- 该研究突出了磁场效应在材料工程中的潜力,用于储能应用.
相关概念视频
Ferromagnetism
2.4K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.4K
Colors and Magnetism
11.6K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
11.6K
Diamagnetism
2.4K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.4K
Paramagnetism
2.5K
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
2.5K
Atomic Nuclei: Nuclear Spin State Overview
921
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
921


