捕获素阳离子在化性化多孔有机聚合物中,用于高度循环稳定的阴极材料
Zhaolei Wang1, Qiaoyan Qi1, Weize Jin1
1Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.
Small (Weinheim an der Bergstrasse, Germany)
|July 25, 2023
概括
基于viologen的新型聚合物使素固定,克服了离子电池中的溶解性问题. 这些材料表现出高容量和卓越的循环稳定性,用于先进的能量存储.
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
- 聚合物化学 聚合物化学
背景情况:
- 素 (Br2,I2) 为离子电池阴极提供高能量密度和低成本.
- 素在电解质中的高溶解度导致循环性能差.
- 在先进的电池技术中需要稳定的阴极材料.
研究的目的:
- 设计和合成基于viologen的阴离子多孔有机聚合物 (TpVXs),用于固定离子.
- 为了评估用于离子电池的TpVX电极的电化学性能.
- 研究这些新型材料的电荷储存机制和循环稳定性.
主要方法:
- 合成基于viologen的多孔有机聚合物 (TpVXs).
- 电化学表征,包括特定容量和放电电压测量.
- 在各种C率下进行长期循环稳定性测试.
- 现场拉曼和现场X射线光电子光谱用于机制研究.
主要成果:
- TpVBr和TpVI电极显示出高的初始特定容量 (116和132mAhg-1在0.2C) 和高放电电压 (≈3.0V).
- 实现了优异的长期循环稳定性,在0.5°C的600个循环后保持了86% (TpVBr) 和98% (TpVI) 的容量.
- 性能明显超过了最先进的素电极.
结论:
- 基于viologen的多孔有机聚合物有效地固定素离子,提高电池性能.
- 设计的聚合物为基于素的离子电池提供了稳定和高性能离子电池的有希望的策略.
- 该研究提供了对这些先进的电极材料中电荷存储机制的见解.
更多相关视频
相关概念视频
01:17Ion Exchange
622
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or...
622
00:57Cationic Chain-Growth Polymerization: Mechanism
2.4K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
2.4K
02:46Halogenation of Alkenes
15.8K
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
15.8K
00:56Extraction: Advanced Methods
488
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
488
01:24ortho–para-Directing Deactivators: Halogens
5.6K
Halogens are ortho–para directors. They are more electronegative than carbon. Therefore, as ring substituents, they can withdraw electrons through the inductive effect and deactivate the aromatic ring towards electrophilic substitution. Halogens also have an electron-donating resonance effect on the ring, which influences the orientation of the incoming electrophile. If an electrophile attacks at the ortho or the para position, the halogen donates electrons and stabilizes the intermediate...
5.6K