(Nanowork News) “Designing materials with high conductivity and good performance is very important for the development of alkaline ion batteries,” said Xijun Xu, associate professor in the College of Chemical Engineering and Light Industry at Guangdong University of Technology.
As the development of large-scale power systems such as electric vehicles accelerates, demand for secondary batteries is changing to models that have both high output and economic efficiency. As concerns about energy and the environment increase, the search for sustainable and environmentally friendly energy solutions has also become a research focus.
Currently, lithium-ion batteries dominate the market as the primary choice for energy storage. Nevertheless, the scarce distribution and high cost of lithium resources highlight the importance of exploring alternative solutions, such as high-performance, safe alkaline-ion batteries, which are of great practical importance.
Xu emphasized that covalent organic framework (COF) materials are emerging as promising candidates due to their outstanding electrochemical performance, structural stability, and excellent cycling performance. These materials are attracting attention due to their potential in electronic and energy storage applications.
COFs are particularly noteworthy for their ability to pre-design redox active sites with precise density and location, which improves the energy density of electrode materials. Additionally, incorporating organic functional groups into the COF structure can enhance the transport of metal ions, potentially overcoming the problem of slow ion transport in batteries.
A common strategy to improve the intrinsic conductivity of organic electrode materials involves adding functional groups or heteroatoms with strong electron-withdrawing properties. This approach not only reduces the bandgap but also increases conjugation.
It is important to design COF materials with high stability and capacity, keeping in mind that larger ion sizes in alkaline metal ion batteries can lead to slower ion transport rates and greater volume changes during cycling. The COF design principle of battery systems focuses on controlling the pore structure, chemical reaction sites, and surface functional groups to achieve stable and efficient alkaline ion battery systems.
However, the field of COF batteries is still in its infancy and faces several challenges, including complex synthesis conditions that hinder large-scale production and the presence of structural defects in polycrystalline COFs. Xu emphasized the clear link between the adaptive structure of COFs and battery performance, noting that broad application and improvement of the understanding of electrochemical reactions is important to design high-performance materials. Further research into the application of COFs in batteries is essential, and overcoming current challenges will improve their electrochemical properties, making them more suitable for practical applications.
The author posted his review as follows: Advances in energy materials (“Recent advances and prospects in covalent organic frameworks for alkaline ion batteries”).