Composite shell of lithium ion battery

Abstract

The invention discloses a composite shell of a lithium ion battery. The shell is formed by combining a metal inner layer and a plastic outer layer; the metal inner layer is made of aluminum, aluminum alloy, stainless steel or an alloy material; the thickness of the metal inner layer is between 0.5 and 1.5 millimeters; the plastic outer layer is made of polypropylene (PP), acrylonitrile-butadiene-styrene (ABS), polyethylene (PE) or ethylene propylene diene monomer rubber; the thickness of the plastic outer layer is between 1.5 and 2.5 millimeters; and the metal inner layer and the plastic outer layer are combined and connected by a thermal compound method, a hot injection method, an electroplating method, a nesting method or a bonding method. The composite shell takes metal as an inner layer and plastic as an outer layer, and is small in size, light in weight, high in strength, easy to weld, convenient to combine and high in insulation. By the composite shell formed by combining the metal inner layer and the plastic outer layer, the requirements of a shell of a power battery which is relatively small in size, relatively light in weight, relatively high in strength and relatively easy to weld are met.

Description

technical field [0001] The invention relates to a housing, in particular to a composite housing of a lithium ion battery. Background technique [0002] With the lack of oil, coal and other resources, the global energy situation is becoming increasingly tense. As a clean, practical and easy-to-achieve energy source, electric energy is becoming more and more popular. Batteries, especially power batteries, are therefore becoming more and more important. At present, power battery shells can be divided into four categories: stainless steel, plastic shells, aluminum shells, and aluminum-plastic molds according to different materials. The advantages and disadvantages of the four shells are as follows: [0003] 1. Stainless steel metal materials are mainly used in batteries with large and medium capacity (generally above 20AH). Its advantages are easy sealing, stable material, high shell strength, small size, and the battery core is not easily damaged by extrusion. . However, d...

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Problems solved by technology

However, the aluminum alloy has low strength and is easy to bulge; secondly, the aluminum material has an oxide layer on the surface and is reflective; in addition, the welding effect of commonly used laser welding is poor; thirdly, when the battery made of aluminum shell is used in electric vehicles, An insulation layer is also required between the battery and the battery; this undoubtedly increases the cost

[0006] 4. The aluminum-plastic molded soft shell is the lightest in weight and the smallest in volume. It adopts a three-layer composite structure, with aluminum foil in the middle and thin plastic materials on both sides, but the shell strength of this material is not high. High, can not effectively protect the internal core, and when it is used as a power battery, too many series and parallel connections will cause too many hidden dangers at the aluminum lugs of the aluminum-plastic film to nickel, resulting in a drop in battery capacity; and because the outer shell is too Weak, aluminum-plastic film and tabs for power batteries are not yet mature, so very few manufacturers will choose aluminum-plastic film

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