Membrane and electrochemical device comprising same

Abstract

The present invention relates to a membrane and an electrochemical device comprising the same. The membrane is characterized in that the membrane at least comprises a porous substrate and a discontinuous adhesive layer provided on at least one side surface of the porous substrate; the non-continuous bonding layer comprises a coating area and a blank area; and the coating area contains slurry of acompound formed by electrostatic self-assembly of organic matters and inorganic matters. The blank area provides a channel for electrolyte infiltration of the electrochemical device, so the infiltration of the electrolyte can be accelerated, the electrolyte injection time and the standing time of the battery are shortened, the electrolyte retention amount of the battery is increased, and the cyclic service life of the battery is prolonged; and the non-continuous bonding layer of the isolating membrane has a bonding effect, so the porous substrate can be bonded with the positive electrode and the negative electrode to form a good interface, the deformation of the battery in the use process is prevented, the complete risk is reduced, and the cycle performance and the energy density are improved.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a diaphragm and an electrochemical device comprising the diaphragm. Background technique [0002] Power batteries, consumer electronics and energy storage fields have higher and higher requirements on the cycle life of chemical devices such as lithium-ion batteries, and longer cycle life requires more electrolyte retention. One of the current technical difficulties in increasing the electrolyte retention of lithium-ion batteries is how to speed up the infiltration speed of the electrolyte, so that more electrolyte can be injected within a certain period of time. Lithium-ion battery manufacturers mostly speed up the infiltration by continuously optimizing the standing conditions after liquid injection, such as placing the cells horizontally, prolonging the standing time, increasing the standing temperature, etc., but these cannot fundamentally solve the problem of electr...

AI Technical Summary

Problems solved by technology

Most lithium-ion battery manufacturers speed up the infiltration by continuously optimizing the standing conditions after liquid injection, such as placing the cells horizontally, prolonging the standing time, increasing the standing temperature, etc., but these cannot fundamentally solve the problem of electrolyte infiltration inside the battery. The problem of slowness, because the electrolyte does not have enough channels to flow inside the battery, it is necessary to find a way to set up more channels inside the battery, on the one hand, to speed up the flow of the electrolyte, and on the other hand, it can accommodate more electrolyte

[0003] In order to solve this problem from the root, some people reduce the compaction density of the pole piece, which reduces the capacity of the battery and cannot meet the requirements of high energy density.

There are also people who treat the positive and negative electrodes, such as corona, to increase the surface roughness and gaps of the electrodes, and to speed up the infiltration of the electrolyte. This method not only loses part of the energy, but also affects the battery interface, which will lead to battery failure. Deformation of pole pieces during long-term charging and discharging, which increases safety risks

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