Battery separator, preparation method thereof and lithium ion battery

Abstract

The invention provides a battery separator, a preparation method thereof and a lithium ion battery, the battery separator comprises a separator substrate and a conductive coating coated on at least one surface of the substrate, and the raw materials of the conductive coating comprise a binder and a conductive material. The problem of static electricity generated in the use process of the partitionplate can be effectively solved, the foreign matter adsorption probability is reduced, and the comprehensive quality of safety, circularity and the like of the battery is improved.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a battery separator, a preparation method thereof and a lithium ion battery formed by using the separator. Background technique [0002] Lithium-ion batteries have the characteristics of high energy density, long cycle life, no memory effect, and environmental protection. As energy storage devices, they are widely used in consumer electronics and power tools. As an important component of lithium-ion batteries, the battery separator determines the interface structure and internal resistance of the battery, and directly affects the cycle, capacity and safety of the battery. [0003] At present, lithium-ion batteries mainly use porous polymer substrates as separators (or diaphragms), which are arranged between the positive and negative electrodes. The interface between them is easy to change, so that the gap between the two increases, which leads to problems such as battery cap...

AI Technical Summary

Problems solved by technology

[0004] However, non-aqueous adhesive-coated separators often produce a large electrostatic effect during use, which not only seriously affects the normal production process when lithium-ion batteries are wound, but also easily absorbs foreign matter such as dust and affects battery quality. The solution to the static electricity problem mainly includes: (1) neutralize the charge by using additional devices (such as ion blower, static elimination bar, etc.) during the lithium ion battery winding process or introduce the charge into the ground to eliminate static electricity. This kind of method can only partially or temporarily eliminate the static electricity on the glued separator, if the separator is rubbed in the subsequent production process, it will still generate static electricity, and it cannot eliminate the static electricity from the source; (2) Add anti-static electricity to the glued layer Antistatic agents and antistatic agents are generally surfactants with both polar and non-polar groups. The polar hydrophilic groups can absorb a small amount of water on the surface of the separator to achieve the purpose of removing static electricity. However, antistatic The chemical composition of the agent is easy to produce side reactions in the internal environment of the battery, and the introduced moisture will often react with the lithium salt in the electrolyte to produce a large amount of gas, which will cause the battery to swell and adversely affect the quality of the battery.

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