Pouch Battery Electrolyte Reinjection Through a Sealable Functional Hole

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Solution Overview

Problem

The electrolyte in secondary batteries is consumed during repeated charging and discharging, leading to performance degradation.

Innovation Solution

A method for reinjecting electrolyte into a secondary battery using a pouch with a functional hole covered by a polymer layer permeable to CO and CO2 gases, allowing gas discharge and electrolyte injection, followed by sealing the hole.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the battery is disassembled to replace the electrolyte, then the electrolyte can be replaced, but the disassembly and reassembly processes increase the risk of damage and require high manual skills

Engineering Contradiction:
Improveelectrolyte replacement reliabilityVSAvoiddisassembly and reassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The battery is divided into separable modules: the battery case, battery electrodes, and battery cover with electrolyte injection hole. This allows the electrolyte to be accessed and replaced without disassembling the entire battery, reducing complexity while maintaining replacement reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The battery is designed with self-service capabilities through the electrolyte injection hole and sealing structure, allowing electrolyte replacement without requiring professional disassembly and reassembly procedures, thereby reducing operational complexity and damage risk.

Inventive Principle:
Principle #25Self-service

2Reliability

If the battery case is sealed hermetically, then moisture and air are prevented from entering, but the electrolyte cannot be supplemented or replaced

Engineering Contradiction:
Improvebattery protection against moisture and airVSAvoidelectrolyte replenishment capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

A sealing structure with an electrolyte injection hole serves as an intermediary element. It maintains hermetic sealing to prevent moisture and air entry while providing a controlled access point for electrolyte supplementation and replacement, thus resolving the contradiction between protection and adaptability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing structure has different functional zones: most areas provide hermetic sealing to prevent moisture and air entry, while a specific local area (injection hole) allows controlled electrolyte access. This local differentiation resolves the contradiction between overall sealing and localized accessibility.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If the positive and negative electrodes are wound into a spool shape, then the battery structure is compact, but the electrolyte distribution becomes uneven and immersion is insufficient

Engineering Contradiction:
Improvebattery structure compactnessVSAvoidelectrolyte distribution uniformity
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The battery electrodes are designed to be movable rather than fixed in a rigid spool configuration. This allows the electrodes to dynamically adjust their position and orientation during electrolyte filling, enabling better electrolyte distribution and immersion while maintaining compact structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electrode arrangement transitions from a two-dimensional spool winding to a three-dimensional configuration that allows electrolyte to penetrate and distribute more uniformly throughout the electrode structure, improving immersion while maintaining compactness.

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

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

Facilitates easy electrolyte reinjection and gas discharge, preventing electrolyte leakage and aluminum oxidation, thereby maintaining battery performance.

Implementation Method 1

a bottom surface of the battery case and a top surface of the battery cover are joined to one another through ultrasonic welding

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

a bottom surface of the battery case and a top surface of the battery cover are joined to one another through ultrasonic welding

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentEP4228084B1Electrolyte reinjection method and electrolyte- reinjectable secondary battery
Publication Date: 2026.04.29 LG ENERGY SOLUTION LTD
  • EP4228084B1 patent drawingFigure 1
  • EP4228084B1 patent drawingFigure 2
  • EP4228084B1 patent drawingFigure 3

AI summary

The present invention relates to a method for reinjecting an electrolyte, and a secondary battery capable of being reinjected with an electrolyte. The method for reinjecting an electrolyte according to the present invention is a method for reinjecting an electrolyte into a secondary battery in which an electrode assembly and an electrolyte are accommodated in a pouch. The pouch comprises an aluminium sheet, in which a functional hole is formed, and a polymer layer stacked on the aluminium sheet. The method comprises a reinjection process of injecting an additional electrolyte into the pouch through the functional hole by opening the functional hole, and a sealing process of sealing the functional hole after the reinjection process.