Battery Case Pocket Structure for Uniform Electrolyte Impregnation

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Solution Overview

Problem

The electrolyte impregnation process in secondary batteries faces challenges due to bottlenecks in the flow of electrolyte, leading to trapped gas in the central part of the electrode and difficulty in evenly permeating the electrolyte, which affects the performance and safety of the battery.

Innovation Solution

A battery case design with a receiving portion and a pocket portion that includes a connecting space with a larger cross-sectional area, allowing smooth flow of electrolyte from the pocket space to the receiving space, facilitating even impregnation of the electrode assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the connecting space has a larger cross-sectional area than the main pocket space, then the electrolyte flow is smooth and even impregnation is achieved, but the device complexity increases

Engineering Contradiction:
Improveimpregnation qualityVSAvoidbattery case structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The battery case is segmented into three distinct functional spaces: the receiving space for the electrode assembly, the main pocket space for electrolyte storage, and the connecting space for electrolyte flow. This segmentation allows each space to be optimized independently, with the connecting space specifically designed with a larger cross-sectional area to ensure smooth electrolyte flow and even impregnation, while the overall structure remains manageable through clear functional division.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If electrolyte is injected enough to cover the entire electrode with adjusted pressure, then the electrode is fully impregnated, but gas is trapped in the central part of the electrode

Engineering Contradiction:
Improveelectrolyte amountVSAvoidgas entrapment
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The connecting space acts as an intermediary channel between the main pocket space and the receiving space. Its larger cross-sectional area facilitates smooth electrolyte flow that progressively fills the receiving space from the edges toward the center, allowing gas to escape gradually rather than being trapped. This intermediary space mediates the electrolyte distribution process to prevent gas entrapment while ensuring complete impregnation.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 ensures high-quality impregnation of the electrode assembly, preventing gas entrapment and improving the overall performance and safety of the secondary battery by ensuring uniform electrolyte distribution.

Implementation Method 1

the connecting space has a larger cross-sectional area than the main pocket space... allowing smooth flow of electrolyte from the pocket space to the receiving space

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP4700921A1Battery case, half-assembly for secondary battery comprising same, and method for manufacturing secondary battery
Publication Date: 2026.02.25 LG ENERGY SOLUTION LTD
  • EP4700921A1 patent drawingFigure 1
  • EP4700921A1 patent drawingFigure 2
  • EP4700921A1 patent drawingFigure 3

AI summary

The present disclosure relates to a battery case, a semi-assembly for a secondary battery including the same, and a secondary battery manufacturing method, and a battery case according to one aspect of the present disclosure is a battery case for accommodating an electrode assembly and an electrolyte, and may include a receiving portion having a receiving space for accommodating the electrode assembly; and a pocket portion connected to one side of the receiving portion, wherein the pocket portion may include a main pocket portion having a main pocket space for accommodating the electrolyte; and a connecting portion providing a connecting space that allows the main pocket space and the receiving space to communicate with each other, wherein the connecting space may have a larger cross-sectional area than the main pocket space.