Preparation method of graphene/active carbon composite film

Abstract

The invention discloses a preparation method of a graphene / active carbon composite film. Active carbon is subjected to acid modification treatment, and is then mixed with a graphene oxide dispersion liquid, then the graphene / active carbon mixed solution is subjected to freezing treatment, then a solid mixture after freezing treatment is dried, thermal reduction of a graphene oxide is performed to obtain graphene / active carbon aerogel, finally a roller press or tablet press are adopted to mechanically press the graphene / active carbon aerogel to obtain a graphene / active carbon composite film, active carbon particles are uniformly dispersed in a graphene framework, and the film material has a self-supporting characteristic and has bendability. The preparation method can eliminate a re-stacking phenomenon in the graphene film preparation process, provides an efficient conductive carrier for active carbon, and the prepared composite film material can be separately used as a supercapcitor electrode under the condition of not adding a binder, and has relatively high specific capacitance and stable cycle performance.

Description

technical field [0001] The invention belongs to the technical field of supercapacitor electrode materials, and in particular relates to a preparation method of a graphene / activated carbon composite film and a supercapacitor electrode made of the graphene / activated carbon composite film obtained by the method. Background technique [0002] Supercapacitors have the characteristics of high power density, long cycle life, no pollution, and good safety performance. They have broad application prospects in electric vehicles, space technology, and defense industries, and have become a research hotspot that has attracted widespread attention in recent years. [0003] Carbon materials with high specific surface area are ideal electrode materials for supercapacitors, and activated carbon has been widely used in supercapacitors. In recent years, with the rapid development of portable electronic devices and new energy vehicles, the requirements for supercapacitors are also increasing. F...

AI Technical Summary

Problems solved by technology

However, due to the high specific surface energy of graphene, it is easy to re-stack and lose its original performance in the process of material and electrode preparation, especially in the preparation process of graphene film, graphene sheets will produce order Self-assembly, which greatly reduces its specific surface area and thus affects the performance in supercapacitor applications (Appl. Phys. Lett. 2010, 96, 253105)

[0005] In order to overcome the above problems, the method of using soft and hard separators to prevent the stacking of graphene has appeared in the world. The hard separators include metal oxides, carbon black, etc., and the soft separators include water molecules, electrolyte molecules, etc. , the above schemes are mostly carried out by suction filtration or evaporative self-assembly method in the preparation of graphene membranes, among which the suction filtration method is suitable for small batch preparation, not suitable for mass production (Adv. Mater. 2011, 23, 2833.); and The evaporation self-assembly method is easy to damage the film structure during the reduction process after the graphene oxide film is formed, and has an adverse effect on its mechanical stability (CN103219066A)

Images