A positive electrode of a hybrid capacitor and its preparation method and application

Abstract

The present invention relates to a positive electrode of a hybrid capacitor and its preparation method and use. The positive electrode includes a current collector, and a bonding layer and a positive electrode material layer sequentially located on the surface of the current collector. The bonding layer includes a first binder, The positive electrode material layer includes a second binder, a conductive agent, a positive electrode active material and a lithium-rich compound, the conductive agent includes a first conductive agent and a second conductive agent, and the first conductive agent includes graphite powder, At least one of conductive carbon black or acetylene black, the second conductive agent includes at least one of graphene-based materials and one-dimensional carbon materials. In the positive electrode provided by the present invention, the bonding layer improves the binding ability between the current collector and the positive electrode material layer, reduces the internal resistance of the electrode sheet, and the conductive agent, lithium-rich compound and positive electrode active material in the positive electrode material layer cooperate with each other to improve the positive electrode. Excellent energy density and rate performance, and at the same time provide lithium ions to enter the negative electrode during charging, so as to realize the pre-lithiation-free negative electrode.

Description

technical field [0001] The invention relates to the technical field of hybrid capacitors, in particular to a positive electrode of a hybrid capacitor and its preparation method and application. Background technique [0002] With the increasingly prominent energy and environmental issues, clean energy and renewable energy are widely researched and utilized. As a new type of high-efficiency energy storage element between conventional capacitors and secondary batteries, supercapacitors have received attention and research. Among them, carbon-based supercapacitors use carbon materials as the main electrode materials and are widely used. Activated carbon is one of the commonly used carbon materials, but the specific capacitance of activated carbon is generally between 25-35F / g, and the compacted density is only 0.5- 0.6g / m 2 , The energy density of a capacitor using pure activated carbon as an electrode is only 2-10Wh / kg, which is severely limited. In addition, the activated c...

AI Technical Summary

Problems solved by technology

The positive electrode of the hybrid capacitor solves the problems of low energy density of carbon-based capacitors and the need for pre-intercalated lithium treatment on the negative electrode by improving the formula and process of the conventional positive electrode, improves the energy density and rate performance of the device, and can meet the -40°C- 125℃ high rate pulse discharge

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