Roadmap of amorphous metal-organic framework for electrochemical energy conversion and storage
Hang Wang, Qi Yang, Nan Zheng, Xingwu Zhai, Tao Xu, Zhixin Sun, Liang Wu, Min Zhou
Abstract
Metal-organic frameworks (MOFs), a well-known coordination network involving potential voids, have attracted attention for energy conversion and storage. As far as is known, MOFs are not only believed to be crystalline. Emerging amorphous MOFs (aMOFs) are starting as supplementary to crystalline MOF (cMOF) in various electrochemical energy fields owing to intrinsic superiorities over crystalline states, greater ease of processing, and distinct physical and chemical properties. aMOFs retain the basic skeletons and connectivity of building units but without any long-range order. Such structural features over long range possess the isotropy without grain boundaries, resulting in fast ions flux and uniform distribution. Simultaneously, distinct short-range characteristics provide diverse pore confined environment and abundant active sites, and thus accelerate mass transport and charge transfer during electrochemical reactions. Deep understandings and controllable design of aMOF may broaden the opportunities for both scientific researches beyond crystalline materials and practical applications. To date, comprehensive reviews about aMOFs in the fields of energy conversion and storage remain woefully underrepresented. Herein, we summarize the roadmap of aMOF from the development, structural design, opportunity, application, bottleneck, and perspective. In-depth structure-activity relationships with aMOF chemistry are highlighted in the typical electrochemical energy conversion like water oxidation and energy storage, including supercapacitor and battery. The combination of disordered nature at long range and short range, alongside the dynamic structural changes, is promising to reinforce cognition of aMOF domains with MOF versatility, shedding light on the design for efficient electrochemical energy applications via amorphization.