在Na4VMn中储存离子 (PO4) 3/C有孔的纳米极电极
Hongbo Wang1, Jiayi Zhang1, Jingjing Sun1
1School of Materials Science and Engineering, Henan Institute of Technology, Xinxiang 453000, China.
ACS applied materials & interfaces
|December 9, 2024
概括
碳封装的离子电池阴极材料Na4VMn(PO4) 3 (NVMP) 显示性能有所改善. 纳米结构增强导电性和离子扩散,使稳定的循环和优良的低温耐受性.
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) 是离子电池的有前途的替代品,因为它们含有大量的.
- Na4VMn(PO4) 3 (NVMP) 是一个具有良好的结构稳定性,用于SIB的成本效益高的阴极材料.
- 由于NVMP的电导性较差,这阻碍了其电化学性能和实际应用.
研究的目的:
- 为了提高Na4VMn(PO4) 3 (NVMP) 的电化学性能,用于离子电池.
- 通过纳米结构和碳封装来解决NVMP的导电性限制.
- 为了研究修改过的正极材料的结构完整性和循环稳定性.
主要方法:
- 碳封装NVMP多孔纳米棒的制备,使用电方法.
- 材料的结构,形态和电化学性质的表征.
- 现场X射线衍射用于监测电化学循环期间的结构变化.
主要成果:
- NVMP/C的1D多孔纳米基结构显著改善了电子运输和离子扩散.
- 该材料在0.2°C时具有90.9mA h·g-1的初始可逆容量,在5.0°C时保持68.0mA h·g-1的初始可逆容量.
- 卓越的循环稳定性,在1°C和3°C的800个循环后保持90.4%和89.8%的容量.
- 显著的低温性能,在-30°C下放电能力达到20°C下放电能力的40.1%.
- 在现场XRD证实在充放电周期期间没有晶体结构的扭曲.
结论:
- 电衍生碳封装NVMP多孔纳米棒为SIB提供了高性能阴极材料.
- 纳米架构有效地克服了NVMP的导电性限制,提高了速率能力和循环稳定性.
- 该材料表现出优异的低温耐受性和结构完整性,使其适用于实际的SIB应用.
相关概念视频
02:48Ionic Bonding and Electron Transfer
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.
03:08Electrolytes: van't Hoff Factor
Colligative Properties of ElectrolytesThe colligative properties of a solution depend only on the number, not on the identity, of solute species dissolved. The concentration terms in the equations for various colligative properties (freezing point depression, boiling point elevation, osmotic pressure) pertain to all solute species present in the solution. Nonelectrolytes dissolve physically without dissociation or any other accompanying process. Each molecule that dissolves yields one dissolved...
02:47Voltaic/Galvanic Cells
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,...
03:02Standard Electrode Potentials
On comparing the reactivity of silver and lead, it is observed that the two ionic species, Ag+ (aq) and Pb2+ (aq), show a difference in their redox reactivity towards copper: the silver ion undergoes spontaneous reduction, while the lead ion does not. This relative redox activity can be easily quantified in electrochemical cells by a property called cell potential. This property is commonly known as cell voltage in electrochemistry, and it is a measure of the energy which accompanies the charge...
01:19Potentiometry: Types of Electrodes
Reference electrodes serve as a stable reference point for potentiometric measurements, while indicator and working electrodes react to variations in the composition of a solution.
The Standard Hydrogen Electrode (SHE) is a widely used reference electrode that maintains zero potential across all temperatures. However, its need for a continuous hydrogen gas supply renders it impractical for everyday use.
An alternative to SHE is the Saturated Calomel Electrode (SCE). This electrode features an...
The Standard Hydrogen Electrode (SHE) is a widely used reference electrode that maintains zero potential across all temperatures. However, its need for a continuous hydrogen gas supply renders it impractical for everyday use.
An alternative to SHE is the Saturated Calomel Electrode (SCE). This electrode features an...
01:15Potentiometry: Membrane Electrodes
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...