Covalent organic frameworks(COFs),which are constructed by linking organic building blocks via dynamic covalent bonds,are newly emerged and burgeoning crystalline porous copolymers with features including programmable...
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Covalent organic frameworks(COFs),which are constructed by linking organic building blocks via dynamic covalent bonds,are newly emerged and burgeoning crystalline porous copolymers with features including programmable topological architecture,pre-designable periodic skeleton,well-defined micro-/meso-pore,large specific surface area,and customizable electroactive *** benefits make COFs as promising candidates for advanced electrochemical energy ***,for now,structureengineering of COFs from multiscale aspects has been conducted to enable optimal overall electrochemical performance in terms of structure durability,electrical conductivity,redox activity,and charge *** this review,we give a fundamental and insightful study on the correlations between multi-scale structure engineering and eventual electrochemical properties of COFs,started with introducing their basic chemistries and charge storage *** careful discussion on the significant achievements in structureengineering of COFs from linkages,redox sites,polygon skeleton,crystal nanostructures,and composite microstructures,and further their effects on the electrochemical behavior of COFs are ***,the timely cutting-edge perspectives and in-depth insights into COFbased electrodematerials to rationally screen their electrochemical behaviors for addressing future challenges and implementing electrochemical energy storage applications are proposed.
Suppressing the severe water-induced side reactions and uncontrolled dendrite growth of zinc (Zn) metal anodes is crucial for aqueous Zn-metal batteries to achieve ultra-long cyclic lifespans and promote their practic...
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Suppressing the severe water-induced side reactions and uncontrolled dendrite growth of zinc (Zn) metal anodes is crucial for aqueous Zn-metal batteries to achieve ultra-long cyclic lifespans and promote their practical applications. Herein, a concept of multi-scale (electronic-crystal-geometric) structure design is proposed to precisely construct the hollow amorphous ZnSnO3 cubes (HZTO) for optimizing Zn metal anodes. In situ gas chromatography demonstrates that Zn anodes modified by HZTO (HZTO@Zn) can effectively inhibit the undesired hydrogen evolution. The pH stabilization and corrosion suppression mechanisms are revealed via operando pH detection and in situ Raman analysis. Moreover, comprehensive experimental and theoretical results prove that the amorphous structure and hollow architecture endow the protective HZTO layer with strong Zn affinity and rapid Zn2+ diffusion, which are beneficial for achieving the ideal dendrite-free Zn anode. Accordingly, excellent electrochemical performances for the HZTO@Zn symmetric battery (6900 h at 2 mA cm(-2), 100 times longer than that of bare Zn), HZTO@Zn||V2O5 full battery (99.3% capacity retention after 1100 cycles), and HZTO@Zn||V2O5 pouch cell (120.6 Wh kg(-1) at 1 A g(-1)) are achieved. This work with multi-scalestructure design provides significant guidance to rationally develop advanced protective layers for other ultra-long-life metal batteries.
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