Battery Pack Contact Point Thickness Reduction

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Solution Overview

Problem

Conventional battery packs for laptops are limited in achieving a slim design due to the thickness of the contact point portions, which hinders the development of thinner and lighter laptop computers.

Innovation Solution

A battery pack design where the thickness of the contact point portions is reduced to 70% or less of the remaining case portions, with sheets attached to the outer surfaces of the upper and lower cases, and optionally a metal plate interposed between the case and the sheet for enhanced strength, allowing for a more compact structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If the thickness of the contact point portion is reduced to achieve a thinner battery pack, then the overall thickness of the battery pack is reduced, but the structural strength and appearance quality may deteriorate

Engineering Contradiction:
Improvethickness of contact point portionVSAvoidstructural strength of case
Core Design Contradiction:
Length of stationary objectVSStrength

Solution Approach 1:

The case is designed with non-uniform thickness, where the contact point portions have reduced thickness (70% or less of the remaining portions) while other portions maintain sufficient thickness for structural strength. This local differentiation allows the battery pack to be thinner at critical contact areas without compromising overall structural integrity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The case is formed using polymer resin with flame retardant properties, combining structural function with safety requirements. The material selection allows for thinner sections while maintaining necessary strength and fire safety standards.

Inventive Principle:
Principle #40Composite materials

2Length of stationary object

If the thickness of the contact point portion is reduced to achieve a thinner battery pack, then the overall thickness of the battery pack is reduced, but appearance quality may deteriorate due to sink marks and stress marks

Engineering Contradiction:
Improvethickness of contact point portionVSAvoidappearance quality of case
Core Design Contradiction:
Length of stationary objectVSManufacturing precision

Solution Approach 1:

The case thickness is locally optimized at contact point portions where reduced thickness (70% or less) is acceptable without causing visible appearance defects. Non-contact areas maintain sufficient thickness to prevent sink marks and stress marks, ensuring overall appearance quality.

Inventive Principle:
Principle #3Local quality

3Strength

If sheets are attached to the outer surface of the case at contact point portions, then the structural integrity is enhanced, but the device complexity increases

Engineering Contradiction:
Improvestructural integrity of caseVSAvoidcomplexity of case structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The case is functionally segmented into different thickness zones: thinner contact point portions for reduced overall thickness and thicker remaining portions for structural strength. Sheets are attached specifically at contact point portions to reinforce these areas without adding complexity to the entire case structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3258518B1Battery pack having lower case of small thickness and laptop computer including the same
Publication Date: 2022.02.16 LG ENERGY SOLUTION LTD
  • EP3258518B1 patent drawingFigure 1
  • EP3258518B1 patent drawingFigure 2
  • EP3258518B1 patent drawingFigure 3

AI summary

A battery pack that is mounted to a laptop computer, wherein two or more battery cells that can be charged and discharged are housed in a pack case; the battery cells are cylindrical battery cells having a circular vertical cross-section; the pack case is configured with a lower case in which battery cells are received and an upper case that is coupled to the lower case in order to close and seal the battery cells; in the upper case, a thickness of an upper contact point portion that contacts an upper end external circumferential surface of the battery cells is 70% or less of that of the remaining portions of the upper case, and a first sheet is attached to an outer surface of the upper case corresponding to the upper contact point portion; and in the lower case, a thickness of a lower contact point portion that contacts a lower end external circumferential surface of the battery cells is 70% or less of that of the remaining portions of the lower case, and a second sheet is attached to an outer surface of the lower case corresponding to the lower contact point portion.