揭示了转化机制,将硫化石转化为Mg离子电池的阴极材料
Jinming Pan1, Danmei Gao1, Jianxian Qiao2
1College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, PR China. liuyuping@cqu.edu.cn.
Physical chemistry chemical physics : PCCP
|January 14, 2025
概括
脊柱硫化物Ni3S4和Co3S4对高能量密度可充电Mg电池具有前景. Ni3S4表现出卓越的性能,具有低的Mg迁移障碍和转化反应,可以增强能量储存.
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
- 计算材料科学科学 计算材料科学
背景情况:
- 可充电 (Mg) 电池具有高能量密度的潜力.
- 转换类型的阴极材料,如硫化,使得多电子转移更高的容量.
- 挑战包括体积膨胀,缓慢的动力学和转换阴极中的中相演变.
研究的目的:
- 通过使用第一原理计算,研究螺旋硫化物 (M3S4,M = Co,Ni) 的电子,Mg2+动态和电化学特性.
- 评估它们作为高能量密度Mg电池的转换型阴极的潜力.
主要方法:
- 使用第一原理计算,研究电子带结构,Mg2+扩散途径和形成能量.
- 用巴德电荷分析和Ab initio分子动力学 (AIMD) 来理解反应机制.
- 计算的重点是螺旋类硫化物Co3S4和Ni3S4.4.
主要成果:
- 无论是Co3S4还是Ni3S4,都表现出极好的电导率,带宽差距较低 (分别为0.28 eV和0 eV).
- 脊柱Ni3S4在约1.6V的电压下表现出高的特异性放电容量 (220.8mAhg-1) 和能量密度 (353.3Whkg-1),相对于Mg2+/Mg.
- 低Mg迁移障碍 (1.10eV为Co3S4,0.67eV为Ni3S4) 预测用于"oct → tet → oct"路径.
- 对M3S4两种化合物在深度放电时观察到转化到岩盐相的反应.
结论:
- 与Co3S4和Mo6S8相比,Spinel Ni3S4显示出优越的电化学性能,使其成为一个有前途的阴极材料.
- 计算出的低Mg迁移障碍促进了有效的离子扩散.
- 了解转化反应机制有助于合理设计用于高能量密度Mg电池的先进螺旋硫化物.
相关概念视频
03:45Formation of Complex Ions
23.2K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
23.2K
03:02Colors and Magnetism
11.5K
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...
11.5K
02:48Ionic Bonding and Electron Transfer
41.2K
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
41.2K
03:12Batteries and Fuel Cells
26.9K
A battery is a galvanic cell that is used as a source of electrical power for specific applications. Modern batteries exist in a multitude of forms to accommodate various applications, from tiny button batteries such as those that power wristwatches to the very large batteries used to supply backup energy to municipal power grids. Some batteries are designed for single-use applications and cannot be recharged (primary cells), while others are based on conveniently reversible cell reactions that...
26.9K
02:54Trends in Lattice Energy: Ion Size and Charge
23.7K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
23.7K
02:47Voltaic/Galvanic Cells
56.7K
Spontaneous Chemical Reactions
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
56.7K