Controllable Synthesis of Skeletonized V₂O₅ Microspheres Derived from a V-MOF for Aqueous Zinc-Ion Batteries

Porous layered ZnV2O4@C synthesized based on a bimetallic MOF as a stable cathode material for aqueous zinc ion batteries

“…It can be clearly seen that at small current densities of 0.05–0.5 A g −1 , the initial discharge specific capacity of the present cathode materials synthesized based on bimetallic organic frameworks is significantly higher than that of other spinel-type and vanadium-based oxide cathode materials obtained by doping with heteroatoms and carbon coating, as reported in the literature. 21,22,28,42–49 Meanwhile, compared with vanadium-based oxides reported in the existing literature, the currently designed electrode materials have a higher capacity retention rate. From Fig.…”

“…The formation of the ZVOH phase during discharge has been widely observed in some recently reported aqueous zinc ion batteries. 18,28,36,49 Whereas the formation of the ZVOH phase requires a certain amount of OH − , this ion is not directly available in the electrolyte. Therefore, there must be a spontaneous reaction between the electrode and the electrolyte to obtain the hydroxide, which then further reacts with Zn 2+ in the electrolyte to obtain ZVOH, and during the reaction to obtain OH − , a certain amount of H + is produced, which cannot exist in the electrolyte alone, but also enters the electrode.…”

“…Therefore, there must be a spontaneous reaction between the electrode and the electrolyte to obtain the hydroxide, which then further reacts with Zn 2+ in the electrolyte to obtain ZVOH, and during the reaction to obtain OH − , a certain amount of H + is produced, which cannot exist in the electrolyte alone, but also enters the electrode. 28,49 This means that the cycling process of our electrode involves the joint insertion and extraction of Zn 2+ and H + . The subsequent second charge process was accompanied by the gradual disappearance of the ZVOH diffraction peak and the emergence of the Zn x V 2 O 5 · n H 2 O diffraction peak, based on which it was hypothesized that there existed a reversible mechanism for the interconversion of the two phases during the subsequent cycling process.…”

“…The formation of this structure is achieved through the coordination of transition metal ions or metal clusters with diverse organic ligands, which can result in a porous structure. 25,26 Based on the advantages of metal organic frameworks as precursors in uniform doping of multiple elements and for pore structure regulation, some researchers have recently designed cathode materials using metal organic frameworks as precursors, such as Mn-MOF, 27 V-MOF, 28 and Zn-MOF, 29 and their various derived morphologies have found extensive applications in the energy storage field. 30,31 For example, Li et al prepared carbon-doped amorphous vanadium pentoxide composites (a-V 2 O 5 @C) by carbonization and in situ electrochemically induced transformation of the precursor using vanadium metal–organic frameworks as precursors.…”

Structure–property–performance relationship of vanadium- and manganese-based metal–organic frameworks and their derivatives for energy storage and conversion applications

“…They can promote the effective transfer of electrons to address the requirements to storage and conversion. 32–38 The first porous MOF formed based on vanadium is called MIL-47, 39 which has attracted much attention in relevant literature due to its great specific surface area ( S Langmuir = 1320 m 2 g −1 ), considerable thermal stability (400 °C) in the atmosphere, and significant catalytic effects in oxidation reactions.…”