Electric energy supply unit and ceramic separating layer thereof

Abstract

The invention discloses an electric energy supply unit, comprising a first electrode substrate which comprises a first current collector layer and a first active material layer, wherein the first current collector layer is provided with opposite a first side surface and a second side surface and the first active material layer is disposed on the first side surface of the first current collector layer; a second electrode substrate which comprises a second current collector layer and a second active material layer, wherein the second current collector layer is provided with opposite a first side surface and a second side surface and the second active material layer is disposed on the first side surface of the second current collector layer; and a ceramic separating layer which is disposed between the first electrode substrate and the second electrode substrate and is formed by a plurality of ceramic particles through adhesion of a double adhesive system, wherein the double adhesive system comprising a linear polymer and a bridging polymer. The invention also discloses a ceramic separating layer formed by the plurality of ceramic particles through the adhesion of the double adhesive system, wherein the double adhesive system comprising the linear polymer and the bridging polymer; and a weight percentage of the bridging polymer is 0.01%-60% that of the double adhesive system. The electric energy supply unit has good electric conductivity and high security.

Description

technical field [0001] The present invention relates to an electric power supply unit, which is applied to power supply of various electronic devices, in particular to an electric power supply unit which has a ceramic isolation layer that can withstand high temperature, maintains electronic insulation and increases ionic conductivity. Background technique [0002] The separator (membrane) plays a key role in lithium batteries, it is between the positive and negative layers to prevent the electrodes from making physical contact, and it allows free ions to pass therethrough, and electrons are isolated to prevent A short circuit occurs. It must be chemically and electrochemically stable to the electrolyte or electrode material; and must have a certain mechanical strength so that it can withstand the high tensile strength of the battery during assembly and maintain the spacing between the two electrode layers. Structurally, the separator needs to have sufficient porosity to abs...

AI Technical Summary

Problems solved by technology

[0007] At the same time, because ceramic particles generally have high water content, when removing this adsorbed water, the temperature must be heated to at least 190°C, but the melting point of the general adhesive is not high, for example, PVDF is about 170°C, PVDF-HEP is about It is 120-150°C; therefore, once it is heated above 190°C to remove water, the adhesive will melt and the distribution of holes inside the ceramic separator will change, making the charge transfer worse and affecting the performance of the battery

However, if the holes are formed by the above-mentioned plasticizers, the holes will be filled due to the melting of the adhesive, so that the ionic conductivity cannot be effectively improved.

Furthermore, if such a high temperature state is reached during operation, the adhesive will melt and the isolation layer will disintegrate, which will lead to safety problems such as short circuit, failure or explosion of the battery.

[0008] On the other hand, if polymers with high heat resistance are completely used, such as epoxy resin (Epoxy), acrylic resin (Acrylic Acid), polyacrylonitrile (polyacrylonitrile; PAN), etc., the adhesion is good and also It can withstand high temperature, but its structure is cross-linking. The distribution of holes in the structure is not conducive to the passage of ions, which makes the ion conductivity worse, and it is difficult to apply in battery cells.

Therefore, due to the above-mentioned problems, the current ceramic isolation layer is quite difficult to be practically applied in the industry, and most of them are only placed on the electrode layer or the isolation layer in a thin film

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