Covalent organic framework (COF) materials, known for their robust porous character, sustainability, and abundance, have great potential as cathodes for aqueous Zn-ion batteries (ZIBs). However, their application is hindered by low reversible capacity and discharge voltage. Herein, a donor-acceptor configuration COF (NT-COF) is utilized as the cathode for ZIBs. The cell exhibits a high discharge voltage plateau of ≈1.4 V and a discharge capacity of 214 mAh g at 0.2 A g when utilizing the Mn electrolyte additive in the ZnSO electrolyte. A synergistic combination mechanism is proposed, involving the deposition/dissolution reactions of ZnSO(OH)·4HO and the co-(de)insertion reactions of H and SO in NT-COF. Meanwhile, the NT-COF with a donor-acceptor configuration facilitates efficient generation and separation of electron-hole pairs upon light exposure, thereby enhancing electrochemical reactions within the battery. This leads to a reduction in charging voltage and internal overvoltage, ultimately minimizing electricity consumption. Under ambient weather conditions, the cell exhibits an average discharge capacity of 430 mAh g on sunny days and maintains consistent cycling stability for a duration of 200 cycles (≈19 days) at 0.2 A g. This research inspires the advancement of Zn-organic batteries for high-energy-density aqueous electrochemical energy storage systems or photo-electrochemical batteries.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/smtd.202400557 | DOI Listing |
ACS Nano
January 2025
Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, College of Materials Science and Engineering, Hunan University, Changsha 410082, China.
SiO-based anodes, considered the most promising candidate for high-energy density batteries, have long been bothered by mechanical integrity issues. Research efforts focus on particle modifications, often overlooking the enhancement of interparticle connections, which can reduce the active material content within the electrode. Herein, an integrated electrode with strong covalent bonding at the electrode scale is designed, achieving excellent mechanical stability with ∼95 wt.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
Furthering the field of synthetic organic chemistry from the discrete molecules regime to the extended structure regime, covalent organic frameworks (COFs) represent a new genre of crystalline porous materials featuring designability with molecular-level precision, well-defined porosity, and exceptional stability imparted by the robust covalent linkages reticulating organic molecules. The topology of COFs is a principal feature that regulates their functionality and usability for emerging technologies. Profound comprehension of network topologies and maneuvering them toward targeted applications are crucial to advancing the realm of COF research and developing novel functional materials for exciting breakthroughs.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Humboldt-Universität zu Berlin, Department of Chemistry, Laboratory of Organic Chemistry and Functional Materials, Brook-Taylor-Str. 2, 12489, Berlin, GERMANY.
Here we disclose that spiropyrans are able to undergo dynamic covalent exchange via their corresponding merocyanine isomers. In the latter, the indolinium moieties can be exchanged by a Michael-type addition-elimination sequence, in which a methylene indoline attacks a merocyanine and subsequently the initial indoline fragment is cleaved. The rate and position of the exchange equilibrium strongly depend on the reaction conditions as well as the substitution pattern on the methylene indoline fragments.
View Article and Find Full Text PDFSmall
January 2025
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China.
Covalent organic frameworks (COFs) are a promising platform for heterogeneous photocatalysis due to their stability and design diversity, but their potential is often restricted by unmanageable targeted excitation and charge transfer. Herein, a bimetallic COF integrating photosensitizers and catalytic sites is designed to facilitate locally ultrafast charge transfer, aiming to improve the photocatalytic reduction of CO. The strategy uses a "one-pot" method to synthesize the bimetallic COF (termed PBCOF) through in situ Schiff-base condensation of Pyrene with MBpy (M = Ru, Re) units.
View Article and Find Full Text PDFSmall
January 2025
Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India.
To rival commercial organic electrolytes, it is important to focus on safe, cheap aqueous electrolytes with lower salt concentration (≈5.0 m) and a wider electrochemical stable potential window (ESPW). This study reports the facile synthesis of porphyrin-based covalent organic polymers (PTZ-COP, CBZ-COP, and TPA-COP) through a one-pot aromatic electrophilic polycondensation reaction between pyrrole and monomeric aldehydes (PTZ-CHO, CBZ-CHO and TPA-CHO).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!