Prismatic Battery Cap-Terminal Structure for Higher Capacity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional prismatic secondary batteries face issues of reduced capacity due to space occupation by electrode lead parts and a risk of disconnection at the connecting parts of the positive and negative leads.

Innovation Solution

The prismatic secondary battery design includes an electrode assembly with first and second electrode lead parts connected to first and second terminal parts on the upper case, which are directly welded, eliminating the need for external lead parts and reducing the risk of disconnection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional electrode lead parts are used to connect positive and negative electrodes to terminals, then the battery can be assembled with separate connection components, but the battery capacity is reduced due to space occupation by lead parts and disconnection risk increases

Engineering Contradiction:
Improveconnection reliabilityVSAvoidbattery capacity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent merges the electrode lead parts with the terminal structure by integrating the connection function directly into the cap plate. The positive and negative electrode leads are welded to terminal tabs that are part of the cap plate structure itself, eliminating separate connection components and reducing space occupation while improving connection reliability through a unified structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cap plate structure serves multiple functions: it acts as both the terminal holder and the connection structure for electrode leads. The terminal tabs on the cap plate simultaneously provide electrical connection points and structural support for welding the electrode leads, combining what were previously separate components into a multi-functional element that improves both space utilization and connection reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If electrode lead parts are extended to the top surface for welding to terminals, then electrical connection can be established, but the risk of disconnection at connecting parts increases

Engineering Contradiction:
Improvewelding accessibilityVSAvoidconnection stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent combines the terminal structure with the connection structure, so that the terminal tabs are integral parts of the cap plate. This merging eliminates separate welding joints between terminal components and electrode leads, reducing the number of potential disconnection points while maintaining welding accessibility through the top surface configuration.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of extending electrode leads upward to connect to separate terminal components, the patent inverts the approach by having terminal tabs extend downward from the cap plate to connect directly to the electrode leads. This inversion reduces the length of exposed lead parts and minimizes connection points that could fail.

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

3Adaptability or versatility

If separate terminal components are used to connect electrode leads, then the battery structure can be modularized, but the overall device complexity increases

Engineering Contradiction:
Improvestructural modularityVSAvoidconnection structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the terminal structure with the cap plate into a unified component. The terminal tabs are formed as integral parts of the cap plate structure, eliminating the need for separate terminal components and reducing assembly steps. This merging simplifies the connection structure while maintaining the functional modularity needed for battery assembly.

Inventive Principle:
Principle #5Merging (Combining)

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

This configuration maximizes battery capacity by utilizing side space and significantly reduces the risk of disconnection, enhancing the overall performance and safety of the battery.

Implementation Method 1

the first electrode lead part is electrically connected to the first terminal part, and the second electrode lead part is electrically connected to the second terminal part

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP4311000B1Prismatic secondary battery
Publication Date: 2026.01.28 LG ENERGY SOLUTION LTD
  • EP4311000B1 patent drawingFigure 1
  • EP4311000B1 patent drawingFigure 2
  • EP4311000B1 patent drawingFigure 3~4

AI summary

Disclosed herein relates to a prismatic secondary battery including: an electrode assembly including a first electrode lead part formed in a first side direction and a second electrode lead part formed in a second side direction opposite the first side direction; a lower case having an open upper surface and housing the electrode assembly therein; and an upper case covering the open upper surface of the lower case, wherein the upper case includes: a first terminal part bent from a top surface of the upper case corresponding to the open upper surface of the lower case and extending downwardly in the first side direction; and a second terminal part bent from the top surface of the upper case and extending downwardly in the second side direction, wherein the first electrode lead part is electrically connected to the first terminal part, and the second electrode lead part is electrically connected to the second terminal part.