带排序的超级网格使可逆离子还原和稳定的高压离子电池阴极成为可能
Yang Yu1, Qianjiang Mao1, Deniz Wong2
1Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
Journal of the American Chemical Society
|August 1, 2024
概括
这项研究通过调节结构演变和离子氧化还原反应,为离子电池 (SIB) 引入了稳定的高压阴极. 这大大提高了容量保留和电压稳定性,提高了电池性能.
科学领域:
- 材料科学
- 电化学
- 能量储存
背景情况:
- 高压层氧化物正极对于离子电池 (SIB) 非常重要,因为它们的能量密度很高.
- 然而,在高电压下运行往往会导致快速的容量衰减,限制SIB的性能.
- 了解结构变化和离子氧化还原反应 (ARR) 之间的相互作用是克服这一局限性的关键.
研究的目的:
- 为SIB开发稳定的高压阴极材料,以减轻容量衰减.
- 阐明结构演变和阴离子氧化还原反应之间的内在合机制.
- 为高性能O3型氧化物阴极提供设计原则.
主要方法:
- 合成一种新的NaLi0.1Ni0.35Mn0.3Ti0.25O2阴极,具有带状的超级晶格结构.
- 通过电化学测试和分析,研究结构演变及其与离子氧化还原反应 (ARR) 的相关性.
- 分析引入在稳定结构和调节ARR途径中的作用.
主要成果:
- 引入Li到分层的氧化物结构会产生Li-O-Na的配置,激活可逆的O2p类型ARR.
- 这种引入使离子迁移可逆,抑制不可逆的过渡金属离子迁移并稳定O3型结构.
- 修改后的阴极显示了增强的可逆结合的O2p (O2p) 型ARR,抑制了氧二聚体的形成,并抑制了不可逆的分子氧 (O2) 型ARR,从而提高了电化学性能.
- 放电容量从154到168mA hg-1增加,200个循环后容量保持率从35%提高到84%,电压保持率从78%提高到93%.
结论:
- 开发的NaLi0.1Ni0.35Mn0.3Ti0.25O2阴极在SIB中表现出显著的稳定性和高电压性能.
- 这项研究表明,调节结构演变和激活可逆离子氧化还原反应对于抑制容量衰减和电压衰减至关重要.
- 这项工作为设计下一代离子电池的先进高压氧化物阴极提供了宝贵的见解.
相关概念视频
02:47Voltaic/Galvanic Cells
56.9K
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,...
56.9K
02:48Ionic Bonding and Electron Transfer
41.3K
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.
41.3K
03:12Batteries and Fuel Cells
27.2K
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...
27.2K
03:00Electrolysis
26.2K
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
26.2K
02:42Ionic Crystal Structures
14.2K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
14.2K
02:54Trends in Lattice Energy: Ion Size and Charge
23.8K
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:
23.8K