Preparation Of High-performance Zinc-Ion Battery Catheode Material And Its Electrochemical Performance

Significant growth in energy consumption over the past few decades has promoted the transformation of the world energy pattern.People also have more demand for excellent energy storage equipment.High energy density lithium ion batteries（LIBs）have dominated the market for commercial rechargeable batteries.However,people’s concerns about cost,safety,and limited lithium resources are increasing,and they are increasingly concerned about the impact on the environment.Finding a new alternative battery system is an inevitable choice to adjust the current energy structure.To meet this demand,the focus is on developing and applying emerging technology battery systems,exploring suitable electrode materials is an effective method.If a major breakthrough is to be achieved in the current research work of aqueous zinc-ion batteries,they still face the problem of lack of suitable cathode materials to provide them with excellent structural stability and high capacity during the storage of ions.Materials with multi-electron reaction properties are a class of very promising electrode materials.Vanadium-based materials are a typical class of materials that can realize multi-electron reactions due to the variability of the valence state of vanadium.With the further development of advanced electrolytes and the further study on the mechanism of energy storage,vanadium oxide-based multivalent metal ion batteries are expected to become one of the new generation battery technologies.In recent years,vanadium oxide has made great progress in aqueous ZIBs.In this paper,we synthesized one-dimensional vanadium oxide nanomaterials with different morphological characteristics for the anode materials of zinc ion batteries,and compared their electrochemical performance.The electrochemical properties of these three different vanadium based anode materials were compared,and it was concluded that Zn₂V₂O₇ had better electrochemical properties among the three materials,which was more suitable for the next step.Then we optimized the material.Designing the material into an optimized hierarchical structure is an important strategy to achieve the functional performance of the material.In this work,we introduce a novel intricate hollow structure,bubble-encapsulated double-shelled hollow spheres（BDHS）for Zn2V2O7 composite.This hierarchical structure not only possesses a highly porous skeleton for fast ion transport,but also provides more active sites for electrochemical reaction,and thus is favorable for fast kinetics and high energy storage.The process of evolution of the BDHS structure is probed and a dual-template mechanism based on both the colloid and the gas/liquid interface soft templates is disclosed.On the one hand,the surfactant constructs the spherical micelles,which form the“colloid-based soft template”to fabricate the bulk hollow spheres;on the other hand,the in situ formed gas bubbles absorbed on the surface of the hollow spheres construct another“gas/liquid interface soft template”to fabricate the hemi-spherical protuberances on the bulk spheres.The double-shelled hollow spheres form the bulk architecture,and the small bubbles connect to build an additional outside layer on its surface.In this work,we introduce a novel intricate hollow structure,bubble-encapsulated double-shelled hollow spheres（BDHSs）,to achieve fast kinetics and a superior high rate performance for rechargeable aqueous Zn-ion batteries.The unique structure and nanoscale crystals enable better capacitive behavior and superior high rate properties of the Zn2V2O7 BDHS sample over reference samples.In addition,the influences of the designed architecture on capacitive behavior and electrochemical kinetics were carefully investigated.The BDHS sample achieves better high-rate charge/discharge properties and long-term cycling properties than the reference samples,demonstrating its superiority in electrochemical performance.Therefore,the present work introduces a highly efficient architecture to realize a superior electrochemical performance for electroactive materials,which also provides a new clue to propel the development of functional materials in various fields,such as catalysis,medicine and electronics.