A kind of application method of lithium ion battery

Abstract

The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a lithium-ion battery diaphragm and its application. The diaphragm includes a positive insulating layer, a negative insulating layer, and a porous conductive layer arranged between the positive insulating layer and the negative insulating layer. The porous The conductive layer is at least one of graphene layer, carbon fiber layer, carbon nanotube layer and conductive carbon layer. Compared with the prior art, on the one hand, the carbon material used in the porous conductive layer of the present invention has high flexibility, which can increase the flexibility and stability of the diaphragm; and the carbon material itself has abundant micropores, which is conducive to the transmission of lithium ions. At the same time, since the conductive carbon material is used in both positive and negative electrodes, its compatibility with the internal system of the battery is better, so that it can exist stably without affecting the safety performance of the battery; on the other hand, the porous conductive layer has the traditional The diaphragm does not have the function of monitoring the internal parameters of the battery. This function can try to avoid safety problems caused by the internal short circuit of the lithium-ion battery.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an application method of lithium ion batteries. Background technique [0002] Lithium-ion batteries are widely used because of their high voltage, high specific energy, long life, no memory effect, and small self-discharge. However, portable electronic devices have higher and higher requirements on the energy density and charging speed of lithium-ion batteries. [0003] Among them, the negative electrode material has a great influence on the energy density of lithium-ion batteries. The currently commercialized lithium-ion battery anode materials are generally graphite, silicon alloy, tin alloy, etc., but their theoretical energy density is lower than that of metal lithium. Therefore, in recent years, the research and commercialization of lithium ion batteries using metal lithium as the negative electrode material are in full swing. At present, in the a...

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Problems solved by technology

[0006] 1) The diaphragm itself must have micropores to ensure that lithium ions can freely travel between the positive and negative electrodes; while the metal itself is relatively dense, which is equivalent to adding a barrier layer in the middle of the diaphragm, which greatly increases the space for lithium ions to shuttle between them. difficulty;

[0007] 2) The flexibility of the metal is poor, and it is difficult to meet the good flexibility characteristics of the separator; moreover, it is difficult to compound the metal on the insulating substrate, and at the same time, the bonding strength is low, and the problem of interlayer peeling is easy to occur;

[0008] 3) The thickness of the metal layer cannot be made very thin unless electroplating is used, but it is difficult to perform electroplating on an insulating diaphragm substrate;

[0009] 4) Because the metal itself has an electrochemical window, setting a metal layer in the separator is equivalent to introducing an impurity source into the battery, which is quite dangerous and has low reliability and safety

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