Template-assisted Preparation Of Hierarchical-Structure Nanomaterials For Supercapacitor

In order to meet the needs of modern electric equipment(such as electric vehicles,mobile power supplies,etc.),high-performance energy storage devices become the current research hotspots.How to achieve long-circulation performance,high energy density and high power density of energy storage devices is urgently need to be solved.Electrode material is the key factor for determining the performance of energy storage devices.Materials with single structure or composition may not exhibit good electrochemical energy storage properties when used alone as electrode material.Therefore,by designing the structure or composition of the electrode material reasonably,preparation of hierarchical structure nanomaterial with multi-component synergistic effect is one of the effective ways to improve the electrochemical energy storage performance of the electrode material.The template method can effectively prepare nanomaterials with diverse compositions and structures,and has the characteristics of simple and controllable.As a commonly used template for preparing electrode materials,metal salts can directly or indirectly affect the nucleation growth process of the prepared materials,thereby obtaining nanomaterials with diverse structures.In addition,metal salts can be removed by simple water washing and then recycled.However,the current research on the preparation of energy storage electrode materials with hierarchical structure based on salt template still has the following problems:(1)the structure is difficult to control;(2)the preparation cost is high;(3)the preparation process is cumbersome.Based on the problems of the above-mentioned hierarchical structure nanomaterials in the practical application of supercapacitors,the research on templateassisted preparation of hierarchical-structure nanomaterials for supercapacitor was carried out,and how to prepare a hierarchical structure energy storage electrode material based on salt template to realize structure control,simple method and low cost has been explored.The details are as follows:(1)Based on the existing problems that the hierarchical structure of nanomaterials is difficult to be prepared controllably.we selected nickel foam and nickel chloride metal salt as research objects.A study on the controllable preparation of 3D graphene/two-dimensional nickel-cobalt precursor/two-dimensional MOF composite was carried out,focusing on analyzing the influence of the concentration of MOF synthetic solution on the structure and morphology of three-dimensional graphene/twodimensional nickel-cobalt precursor/two-dimensional MOF composites.The controllable preparation of three-dimensional graphene/two-dimensional nickel-cobalt precursor/two-dimensional MOF composite was realized.(2)Based on the high cost of preparation of hierarchical nanostructured materials,we selected sucrose and nickel chloride as research objects,and carried out research on how to prepare low-cost porous carbon materials,focusing on the influence of the ratio of sucrose to nickel chloride on the structure and morphology of porous carbon materials.And low-cost preparation of porous carbon materials was realized.(3)Based on the problem of how to efficiently prepare hierarchical structure nanomaterial,we selected potassium nitrate and ZIF-67 as research objects,and carried out research on how to prepare two-dimensional hierarchical structure nanomaterials,focusing on the the influence of the existence of potassium nitrate and centrifugation washings degree in the post-treatment process on the structure and morphology of ZIF-67,and the efficient preparation of two-dimensional sheet-ZIF-67 was realized.