Hybrid capacitor and its preparation method

Abstract

The invention belongs to the capacitor field, and discloses a hybrid capacitor and electrodes of the hybrid capacitor. The electrodes of the hybrid capacitor comprise a positive electrode and a negative electrode. Materials of the positive electrode comprise aluminum foil and positive electrode active materials composed of a graphene mixture, a first conductive agent and a first binder which are coated on the aluminum foil, and the graphene mixture comprises graphene and nickel cobalt manganese ternary materials in a mass ratio of 1: (0.1-1). Materials of the negative electrode comprise aluminum foil and negative electrode active materials composed of graphite, a second conductive agent and a second binder which are coated on the aluminum foil. According to the hybrid capacitor and a preparation method thereof, the negative electrode materials are provided with a low potential platform, so that the average working voltage of the hybrid capacitor is higher than that of a traditional double electric layer capacitor, and the system energy density is raised; and the positive electrode uses graphene with a high specific area and an outstanding conductivity, so that the internal resistance of the whole capacitor can be reduced effectively, and the hybrid capacitor can form a high specific capacitance.

Description

technical field [0001] The invention belongs to the field of capacitors, and relates to a hybrid capacitor. The invention also relates to a preparation method of the hybrid capacitor. Background technique [0002] In the 1990s, the development of electric vehicles and the need for power pulse power supplies further stimulated research on electrochemical capacitors. At present, the specific energy of electrochemical capacitors is still relatively low, and the specific power of batteries is low. People are trying to solve this problem from two aspects: (1) When batteries and supercapacitors are used in combination, during normal operation, the batteries provide the required energy. The power; when starting or needing a large current discharge, it is provided by a capacitor. On the one hand, it can improve the shortcoming of the battery’s poor low-temperature performance; it can solve the application of pulse current with high power requirements, such as GSM, GPRS, etc. . Th...

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Problems solved by technology

However, most of the micropore specific surface area of ​​the high specific surface area activated carbon currently used cannot form an effective capacitance. At the same time, the conductivity of the activated carbon material itself is not high, which affects the internal resistance of the capacitor, making the energy density of the capacitor low, resulting in low specific capacitance of the capacitor.

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