Battery Pack Composite Covering for Strength and Sealing
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Solution Overview
Problem
Existing battery packs face challenges in achieving a balance between being thin, having high volume efficiency, and maintaining battery strength, while also ensuring excellent sealing properties and heat radiation properties.
Innovation Solution
A battery pack design featuring a flexible covering material with three sealed sides and a rigid covering material with a four-layer or three-layer structure, including a heat-bonding layer for improved adhesion and sealing, and a metal layer for heat radiation, using materials like ethylene-vinyl acetate copolymer and polyamide resins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a thin battery is produced using an aluminum laminated film as external packaging, then the battery thickness is reduced and volume efficiency is improved, but the battery strength becomes small and it is difficult to use as a battery pack
Solution Approach 1:
The patent uses a composite packaging structure consisting of an aluminum laminated film (thin layer) combined with a plastic pack housing. The aluminum film provides barrier properties and the plastic housing provides mechanical strength, creating a composite material solution that achieves both thinness and strength requirements for the battery pack.
2Strength
If a pack housing made of plastic is used to contain the battery element, then the battery strength is improved, but the metal ratio in external packaging is small and heat radiation properties become poor
Solution Approach 1:
The patent employs a composite packaging structure where a thin aluminum laminated film is combined with a plastic pack housing. The aluminum layer, though thin, provides sufficient mechanical strength when integrated with the plastic housing, while also maintaining good heat radiation properties due to the metallic content, thus resolving the contradiction between strength and heat radiation.
3Strength
If aluminum with thickness of 150 to 200 μm is used as the external packaging case, then high battery strength is obtained, but the battery thickness increases and volume efficiency decreases
Solution Approach 1:
The patent segments the packaging function into two parts: a thin aluminum laminated film (providing barrier and partial structural function) and a plastic pack housing (providing primary mechanical strength and protection). This segmentation allows the aluminum layer to be much thinner than conventional single-layer aluminum packaging, improving volume efficiency while the plastic housing compensates for structural strength.
Solution Approach 2:
By combining the thin aluminum laminated film with the plastic pack housing to create a composite packaging structure, the patent achieves high battery strength without requiring a thick aluminum case, thus maintaining thin battery profile and high volume efficiency.
4Strength
If a rigid laminated film is used to constitute the outermost layer of the battery, then excellent volume efficiency and battery strength are achieved, but the sealing properties become poor and moisture easily enters the battery
Solution Approach 1:
The patent uses a composite structure where the aluminum laminated film (with excellent moisture barrier properties) is combined with the plastic pack housing (with rigid structural properties). This composite approach maintains the moisture-sealing advantages of the aluminum film while gaining the strength and rigidity of the plastic housing, preventing moisture ingress despite the rigidity of the outer structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves a thin, high-strength battery pack with enhanced sealing and heat radiation properties, reducing moisture ingress and maintaining battery performance.
Implementation Method 1
a rigid covering material for covering the generator device, the rigid covering material having an opening and being bonded to the flexible covering material of the generator device; and a cover fitted into the opening of the rigid covering material, wherein the rigid covering material has a four-layer structure having an outer packaging layer, a metal layer, an inner packaging layer, and a heat-bonding layer which are stacked on one another
Data Source
AI summary
A battery pack is provided. The battery pack includes: a generator device having a battery element disposed on a flexible covering material folded to cover the battery element, wherein three sides of the flexible covering material around the battery element are sealed; a rigid covering material for covering the generator device, having an opening and being bonded to the flexible covering material of the generator device; and a cover fitted into the opening of the rigid covering material, wherein the rigid covering material has a three-layer structure having an outer packaging layer, a metal layer, and a heat-bonding layer which are stacked on one another, and the heat-bonding layer is one selected from an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, an ethyl acrylate copolymer, a methyl acrylate copolymer, a methacrylic acid copolymer, a methyl methacrylate copolymer, polyacrylonitrile, an ethylene vinyl alcohol resin, a polyamide resin, a polyester resin, acid-modified polypropylene, or an ionomer.