Terminal Fixing Structure for Electric Energy Storage Devices

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High capacitance storage devices face challenges in securing internal space within the metal case, leading to increased internal pressure and potential explosion due to gas accumulation, and existing terminal installation methods are bulky and limit the reduction of metal case thickness.

Innovation Solution

The electric energy storage device features a plate-shaped positive electrode internal terminal with an electrolyte impregnation hole and a flange, where the flange is pressed by a terminal-fixing beading portion to securely fix the terminal within the metal case, eliminating the need for an outer beading groove and allowing for a thinner design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a beading process is applied to fix internal terminals to the metal case, then the terminal installation is secured, but the metal case thickness cannot be reduced and inner space is limited

Engineering Contradiction:
Improveterminal installation securityVSAvoidinner space of metal case
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The invention changes the fixing approach from a two-dimensional beading groove at the terminal's outer circumference to a three-dimensional beading portion protruding into the case's inner space. This dimensional shift allows the terminal to be secured without requiring circumferential grooves, enabling case thinning while maintaining fixation reliability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Instead of forming a groove in the terminal to receive a beading portion (conventional approach), the invention inverts the approach by having the beading portion protrude from the case wall to press against the terminal's outer circumference. This reversal simplifies terminal structure and enables case thinning.

Inventive Principle:
Principle #13The other way round (Inversion)

2Volume of stationary object

If the metal case thickness is reduced to expand inner space, then energy storage capacity is improved, but internal pressure increases due to gas accumulation

Engineering Contradiction:
Improveinner space of metal caseVSAvoidinternal pressure of metal case
Core Design Contradiction:
Volume of stationary objectVSStress or pressure

Solution Approach 1:

The invention applies a beading process to form a protruding portion that presses against the terminal, creating a preliminary restraining force. This pre-applied mechanical constraint counteracts the swelling pressure from gas accumulation, preventing case deformation and potential explosion even when case thickness is reduced.

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If a beading groove is formed at the outer circumference of internal terminals, then terminal fixation is achieved, but terminal structure becomes bulky and complex

Engineering Contradiction:
Improveterminal fixationVSAvoidterminal structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the beading groove from the terminal structure and relocates it to the case wall as a protruding beading portion. This extraction eliminates the need for complex circumferential grooves in the terminal, simplifying terminal design while maintaining secure fixation through the case's beading process.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3249668B1Electric energy storage device having improved installation structure of internal terminal
Publication Date: 2021.08.11 LS MATERIALS CO LTD
  • EP3249668B1 patent drawingFigure 1
  • EP3249668B1 patent drawingFigure 2
  • EP3249668B1 patent drawingFigure 3

AI summary

Disclosed is an electric energy storage device, which includes a positive electrode internal terminal composed of a plate-shaped terminal body having at least one electrolyte impregnation hole formed therein and a flange, wherein an upper surface of the terminal body and any one surface of the flange come into contact with a cell assembly to couple the positive electrode internal terminal and the cell assembly, wherein a lower surface of the terminal body comes into contact with an inner surface of a lower end of a case, and wherein the flange is pressed by a terminal-fixing beading portion so that the positive electrode internal terminal is fixed in the case.