The Application Of Metal Organic Framework In Sodium Ion Battery Anode

In recent years,in order to meet the urgent demand for power supply in the fields of communication,transportation,and power tools,high-energy lithium-ion batteries have received more and more attention as an efficient and clean,low-cost energy storage device.Due to the abundant reserves of metallic sodium in the earth,it is widely distributed and cheap;Semi-electric potential is high and the applicability is wider,so sodium ion batteries are expected to be alternatives to lithium ion batteries in the future.However,the radius of sodium is larger than that of lithium ions.Therefore,when traditional lithium ion electrode materials are used in sodium ion batteries,a series of problems such as material expansion,deformation,and even powdery occur during the embedding and deembedding of sodium ions.The cycle stability of the battery is reduced and even safety problems are caused.The metal organic framework(MOF)material has a 3D mesh structure composed of an organic ligand with a central metal atom and a large molecular weight ring structure.It has a large surface area,an extensive aperture distribution and an adjustable structure,and a large number of electrochemical activity sites.At present,the transformation electrode material derived from the metal organic skeleton material as a precursor has been widely used in the negative electrode of sodium ion batteries.This porous material can buffer the changes in the volume of electrode material caused by ion migration and accelerate the electrode reaction.The progress of,Improve electrochemical reaction kinetics.Two MOF materials were prepared in this experiment.They are MOF materials composed of metal Zr as the center metal atom and diamino-terephthalic acid as organic ligands-UIO-66-NH₂ and metal atoms with metal Cu as the center and organic ligands as the homophenate.The Co₃(NO₃)₂(OH)₄@UIO-66-NH₂ and Cu S@HKUST-1 negative materials are then prepared for the anterior body system with two MOF materials respectively.The two negative electrode materials were prepared to form sodium ion batteries with metallic sodium in 1 mol L^-1 Na Cl O₄/PC+EC to perform charge and discharge cycle tests.Electrochemical test results show that at the current density of 0.1 C,after 100 cycles of charging and discharging,The discharge capacity of Co₃(NO₃)₂(OH)₄@UIO-66-NH₂ and Cu S@HKUST-1 materials was 483.3 m Ah g^-1and 396.1 m Ah g^-1,respectively,and the Coulomb efficiency was close to 100%.Compared with the negative electrode materials such as Co₃(NO₃)₂(OH)₄ and Cu S that have not been modified by MOF materials,the electrochemical properties of the converted negative electrode materials after MOF material modification have been significantly improved.The research of this experiment has guiding significance and reference value for the development of negative electrode materials for sodium ion batteries.