Abstract:
Covalent organic framework (COF) aerogels with functional groups offer exceptional processability and functionality for various applications. These hierarchical porous materials combine the advantages of COFs with the benefits of aerogels, overcoming the limitations of conventional insoluble and nonfusible COF powders. However, achieving both high crystallinity and shape retention remains a challenge for functionalized COF aerogels. In this work, we develop a novel and general solvent substitution method for the one-step synthesis of formyl-functionalized COF aerogels without harsh vacuum conditions. These aerogels exhibit excellent processing capabilities, superior mechanical strength, and enhanced functionality. As a proof-of-concept, they were used in adsorption and lithium metal battery applications, significantly maximizing the structural advantages of COFs, e.g.: (i) the hierarchical porous structure is fully wetted by the electrolyte to form continuous transport channels; (ii) the polar groups, which are easier to be acquired, help in desolvation and transfer of Li+; (iii) the regular pore structures stabilize deposition of Li+ and inhibit the growth of lithium dendrites. These combined benefits contribute to a lighter battery with improved energy density and enhanced safety.
摘要:
具有官能团的共价有机骨架(COF)气凝胶为各种应用提供了优异的可加工性和功能性。这些分级多孔材料结合了COF的优点和气凝胶的优点,克服了常规不溶性和不可熔COF粉末的局限性。然而,实现高结晶度和形状保持性对于官能化COF气凝胶仍然是一个挑战。在这项工作中,我们开发了一种新颖的通用溶剂替代方法,用于无需苛刻的真空条件下一步合成甲酰基官能化的COF气凝胶。这些气凝胶表现出优异的加工能力,优越的机械强度,和增强的功能。作为一个概念证明,它们被用于吸附和锂金属电池应用,显著最大化COF的结构优势,例如:(i)分层多孔结构被电解质完全润湿以形成连续的传输通道;(ii)极性基团,更容易获得,有助于Li的去溶剂化和转移;(iii)规则的孔结构稳定了Li的沉积并抑制了锂枝晶的生长。这些组合的益处有助于具有改进的能量密度和增强的安全性的更轻的电池。