Electrode/Electrolytes Design And Interface Investigation Of Aqueous Zinc Ion Battery Under Extreme Conditions

In recent years,advanced electronic intelligence and large-scale energy storage system have shown a burgeoning development driven by the urgent energy demand of family life and industrial applications.Due to high safety reliability,extremely low cost,and environmental friendliness,the aqueous rechargeable batteries have attracted much attention.Zinc ion batteries（ZIBs）reached the top priority due to the merits of outstanding theoretical capacity(820 m Ah g^-1),low redox potential（-0.76 V vs standard hydrogen electrode）,and an abundance of Zn metal.However,in the aqueous electrolyte,the Zn anode is prone to the side reactions of dendrite growth,metal corrosion and HER,while cathode also suffers from ion dissolution and structural collapse,which seriously affects the cycle stability of the battery device.In addition,the presence of H₂O results in narrow electrochemical window and working temperature range of electrolytes,thereby curbing the further development and application of AZIBsThis article focuses on the interface problem of"zinc anode-electrolyte-positive electrode",and proposes electrode interface design and electrolyte optimization strategies to improve the chemical and electrochemical behavior at the interface and enhance the thermodynamic stability and ion transport kinetics of the electrode and electrolytes,eventually developing a new zinc-ion battery system with long life,high safety,wide temperature range and high energy density in extreme conditions.In addition,this article also investigates nucleation-growth-deposition behavior of Zn²⁺and the solvation and desolvation behavior of Zn²⁺at the interfaces,analyzes the reaction mechanism of dendrite growth,metal corrosion and HER,and discusses the structure-function relationship between the components of the electrolyte and the electrodes,essentially establishing the electrode energy storage mechanism,electrode/electrolyte interface chemistry and electrochemical reaction mechanism,and ion transport mechanism around the"zinc anode-electrolytes-cathode"in extreme conditions（large currents,wide temperatures,high discharge depth,and low N/P ratio）.The relationship network of AZIBs helps to analyze and solve problems in essence,providing a good theoretical basis and valuable practical experiences for the development of AZIBs under extreme conditions.The specific research work is as follows:Firstly,the semi-immobilized interface layer was prepared to improve electrochemical performance of zinc anode at wide temperatures by grafting ionic liquid onto the surface of nano-silica and mixing it with polyacrylonitrile.The study shows that the free phase of the interface layer can weaken the interactions among the components of the electrolytes,promote the desolvation behavior and transport kinetics of Zn²⁺,and suppress the side reactions at the interface;while the immobilized phase of the interface layer can reduce the contents and activity of H₂O molecules by strong interactions and form high conjugate racks which can regulate the Zn²⁺concentration field and self-polarizing electric field to guarantee uniform nucleation and planer deposition along（002）plane.Benefiting from advantages above,this strategy significantly improves the thermodynamic stability and ion transport kinetics at the zinc anode/electrolyte interface,and the various full batteries of Zn//Mn O₂,Zn//Mg-V₂O₅and Zn//Mg-V₂O₅exhibit excellent rate performance of 20 A g^-1and ultra-long life of 80000 cycles in extreme conditions.Secondly,the self-separating interface layer was constructed on Zn anode surface to optimize electrodes and electrolytes stabilities by coupling sodium tricyanomethane and polyacrylonitrile,realizing the excellent performance of AZIBs at a wide temperature range.The study shows that the bulk phase of the interface layer can evolve into an electrically responsive shielding layer with C₄N₃polymeric framework and Na⁺on the Zn anode surface,which can regulate the migration pathway and nucleation-growth-deposition behavior of Zn²⁺and inhibit metal corrosion and dendrite growth and other interfacial side reactions,improving the stability of the Zn anode;at the same time,the separating phase of interface layer can diffuse into the electrolyte,regulate the interactions of various components of the electrolytes and the solvation behavior of Zn²⁺,and form a stable interface layer on the cathode surface,leading to excellent structural stability of the cathode.Benefiting from the advantages above,this strategy can adjust the chemical and electrochemical reaction mechanism and ion transport mechanism at electrodes/electrolytes interfaces,and simultaneously broaden the operating temperature range of the electrolyte,realizing excellent electrochemical performance of Zn//Na-V₂O₅full battery under high current(20 A g^-1),high usage rate（57.0%）,and wide temperature range（-35°C～60°C）.Thirdly,a new strategy to dynamically regulate the electrode/electrolyte interface was proposed to improve the electrochemical performance of zinc-iodine batteries by using tris（2-cyanoethyl）borate as an additive to optimize the structure and properties of the electrolytes.The study shows that the additive can optimize the structure-activity relationship of among components of the electrolytes,regulate the hydrogen bond network of H₂O molecules and the solvation structure of Zn²⁺,and improve the kinetics of Zn²⁺ion transport;at the same time,the additive can evolve into a dense,stable gradient solid electrolyte interface layer,which can avoid the continuous corrosion of the zinc anode by the electrolyte,tolerate the volume change of the zinc anode,regulate the transport pathway and nucleation-growth deposition behavior of Zn²⁺,and induce uniform deposition along the（002）crystal plane,improving the cycle stability and reversibility of the zinc anode;in addition,the additive can be adsorbed on the surface of the cathode surface to inhibit the dissolution of the iodine positive electrode,accelerate the conversion of polyiodides,and improve the ion diffusion-conversion kinetics on cathode side.Benefiting from the advantages above,this strategy ensures that Zn anode shows excellent cycle stability of more than 1500 hours and large rate performance of 40 m A cm^-2,and the Zn//I₂full battery still exhibits an ultra-long lifespan and superior energy density at extreme conditions of large currents,high loading and low N/P ratio.