β-MnOOH 转换为 δ-MnO2,具有新的层到层电荷存储作为离子电池的阴极
Jinhui Xu1,2, Qian Liu2, Qingyang Yin2
1School of Chemical Science and Engineering, Institute for Advanced Studies, Tongji University, Shanghai, 200092, China.
Small methods
|April 10, 2025
概括
层层的二氧化 (δ-MnO2) 对水性离子电池 (ZIB) 是有前途的. 化δ-MnO2可实现一种新的层到层的充电存储机制,提高电池性能和可逆性.
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:
- 层结构的birnessite δ-MnO2是水性离子电池 (ZIB) 的潜在阴极材料.
- 当前 δ-MnO2阴极在放电过程中经常形成非层结构,限制可逆电荷存储.
- 传统的分层材料通常依赖于间接电化学来储存电荷.
研究的目的:
- 调查 feitknechtite β-MnOOH 和其同结构化 δ-MnO2作为ZIBs的阴极材料.
- 探索在水性电解质中化 δ-MnO 的电荷储存机制和性能增强.
- 发现基于Mn的阴极中的新相变换,以改进ZIB.
主要方法:
- 通过化方法合成feitknechtiteβ-MnOOH和同结构化δ-MnO2.
- 这些材料作为水性ZIB中以Zn金属阳极作为阴极的应用.
- 实验性表征与理论模拟相结合,以阐明电荷存储机制.
主要成果:
- 化 δ-MnO2,与β-MnOOH相比,层间距较大,表现出更好的电荷转移动力学和Mn氧化还原可逆性.
- 对于化 δ-MnO2阴极,观察到循环性和速率能力的显著提高.
- 揭示了一种新的层到层电荷存储机制,涉及化δ-MnO和β-MnOOH之间的可逆转换.
结论:
- 在化δ-MnO2中β-MnOOH的微不足道存在促进了用于电荷存储的独特相变.
- 与β-MnOOH相比,化δ-MnO2在水性ZIB中表现出优越的性能.
- 这项研究为ZIBs开发高效的分层阴极材料开辟了新的途径.
更多相关视频
相关概念视频
01:13¹H NMR: Complex Splitting
1.2K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.2K
00:48¹H NMR of Labile Protons: Deuterium (²H) Substitution
824
This lesson illustrates the role of deuterium substitution in simplifying the NMR spectrum of compounds comprising labile protons. One method employed is the use of deuterium. Amongst the three isotopes of hydrogen, deuterium (2H) has a nucleus composed of one proton and one neutron. When the D2O solvent is added to a pure dry ethanol solution, its labile proton is substituted with deuterium.
824
01:07Nuclear Overhauser Enhancement (NOE)
596
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the Nuclear Overhauser Enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring...
596
01:07Proton (¹H) NMR: Chemical Shift
1.4K
Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei...
Absorption signals of all the protium nuclei...
1.4K
01:13meta-Directing Deactivators: –NO2, –CN, –CHO, –CO2R, –COR, –CO2H
5.3K
All meta-directing substituents are deactivating groups. These substituents withdraw electrons from the aromatic ring, making the ring less reactive toward electrophilic substitution. For example, the nitration of nitrobenzene is 100,000 times slower than that of benzene because of the deactivating effect of the nitro group. The first step in an electrophilic aromatic substitution is the addition of an electrophile to form a resonance-stabilized carbocation. The energy diagrams for...
5.3K
03:08Hydroboration-Oxidation of Alkenes
7.7K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
7.7K