State Key Laboratory of Marine Resource Utilization in South China Sea, School of Chemical Engineering and Technology, Hainan University, Haikou 570228, PR China.
School of Chemistry & Chemical Engineering, Yantai University, Yantai 264005, PR China.
J Colloid Interface Sci. 2023 Sep;645:146-153. doi: 10.1016/j.jcis.2023.04.115. Epub 2023 Apr 28.
Covalent organic frameworks (COFs) are considered as a class of potential candidates for energy storage and catalysis. In this work, a COF containing sulfonic groups was prepared to be a modified separator in lithium-sulfur batteries (LSBs). Benefiting from the charged sulfonic groups, the COF-SO cell exhibited higher ionic conductivity (1.83 mS⋅cm). Moreover, the modified COF-SO separator not only inhibited the shuttle of polysulfide but also promoted Li diffusion, thanks to the electrostatic interaction. The COF-SO cell also showed excellent electrochemical performance that the initial specific capacity of the battery was 890 mA h g at 0.5 C and demonstrated 631 mA h g after 200 cycles. In addition, COF-SO with satisfactory electrical conductivity was also used as an electrocatalyst toward oxygen evolution reaction (OER) via cation-exchange strategy. The electrocatalyst COF-SO@FeNi possessed a low overpotential (350 mV at 10 mA cm) in an alkaline aqueous electrolyte. Furthermore, COF-SO@FeNi exhibited exceptional stability, and the overpotential increased about 11 mV at a current density of 10 mA cm after 1000 cycles. This work facilitates the application of versatile COFs in the electrochemistry field.
共价有机框架（COFs）被认为是储能和催化领域的潜在候选材料之一。在这项工作中，制备了一种含有磺酸基团的 COF，用作锂硫电池（LSB）的改性隔膜。得益于带电荷的磺酸基团，COF-SO 电池表现出更高的离子电导率（1.83 mS⋅cm）。此外，改性 COF-SO 隔膜不仅通过静电相互作用抑制了多硫化物的穿梭，而且促进了 Li 的扩散。COF-SO 电池还表现出优异的电化学性能，电池的初始比容量在 0.5 C 时为 890 mA h g，经过 200 次循环后为 631 mA h g。此外，具有令人满意电导率的 COF-SO 还通过阳离子交换策略被用作析氧反应（OER）的电催化剂。电催化剂 COF-SO@FeNi 在碱性水溶液电解质中具有低过电势（10 mA cm 时为 350 mV）。此外，COF-SO@FeNi 表现出出色的稳定性，在 10 mA cm 的电流密度下循环 1000 次后，过电势仅增加约 11 mV。这项工作促进了多功能 COFs 在电化学领域的应用。
