Secondary Battery Formation Method for Gas Management

Solution Overview

Problem

The increasing size of the gas collection pocket in pouch-type secondary batteries leads to excessive material consumption and cost, as well as quality issues due to battery swelling from generated gas during the formation process.

Innovation Solution

A formation method for secondary batteries that includes a pre-formation operation to pre-charge the battery, forming a piercing in the gas collection pocket for real-time primary degassing, and a secondary degassing operation to remove gas generated during the pre-formation process, thereby reducing the size of the gas collection pocket and minimizing material usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large gas collection pocket is formed to collect all gas generated during the formation process, then gas collection capability is improved, but pouch material consumption increases and manufacturing cost increases

Engineering Contradiction:

Improvegas collection capabilityVSAvoidpouch material consumption

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent performs preliminary degassing during the pre-formation operation before the main formation process. By removing gas early when the electrode assembly is still relatively compact, the subsequent gas collection pocket can be smaller since less gas needs to be accommodated during the main formation process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The formation process is divided into multiple stages: pre-formation with primary degassing, and main formation with secondary degassing. This segmentation allows gas to be removed in portions rather than requiring a single large pocket to handle all gas generation, reducing the overall pouch material needed.

Inventive Principle:

Principle #1Segmentation

2Volume of stationary object

If a large gas collection pocket is formed to accommodate gas during formation, then gas accommodation capacity is improved, but battery case swelling occurs and quality problems increase

Engineering Contradiction:

Improvegas collection pocket volumeVSAvoidbattery case swelling

Core Design Contradiction:

Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent performs preliminary degassing during the pre-formation operation before the main formation process. By removing gas early when the electrode assembly is still relatively compact, the subsequent gas collection pocket can be smaller since less gas needs to be accommodated during the main formation process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the harmful effect of gas accumulation (which causes swelling) into a beneficial controlled process. By intentionally creating a dedicated gas collection pocket and actively removing gas through degassing operations, the harmful gas is transformed into a manageable byproduct that can be systematically extracted, preventing uncontrolled swelling.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Loss of substance

If the pocket for gas collection is reduced in size to decrease pouch consumption, then material cost is reduced, but gas collection capability deteriorates

Engineering Contradiction:

Improvepouch material consumptionVSAvoidgas collection capability

Core Design Contradiction:

Loss of substanceVSReliability

Solution Approach 1:

The patent performs preliminary degassing during the pre-formation operation before the main formation process. By removing gas early when the electrode assembly is still relatively compact, the subsequent gas collection pocket can be smaller since less gas needs to be accommodated during the main formation process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements continuous degassing throughout the formation process with multiple degassing operations (primary degassing after pre-formation and secondary degassing after main formation). This continuous gas removal maintains effective gas collection capability throughout the entire process despite the reduced pocket size.

Inventive Principle:

Principle #20Continuity of useful action

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 method reduces the size of the gas collection pocket, decreases material costs, and prevents battery case deformation and quality degradation by removing gas generated during the pre-formation process, maintaining the surface quality and stability of the battery.

Implementation Method 1

a primary degassing operation for forming a piercing in the pocket for gas collection, and primarily degassing the gas generated during the pre-formation operation in real time through the piercing

Methodology Applied

Scientific EffectPressure-driven gas flow: Pressure Gradient

Implementation Method 2

a large amount of gas may be generated due to a side reaction between gas resulting from a positive electrode active material and a positive electrode active material and an electrolyte

Methodology Applied

Scientific EffectElectrochemical side reaction: Electrolysis

Data Source

PatentUS20230155163A1Formation Method For Secondary Battery

Publication Date: 2023.05.18 SK ON CO LTD

AI summary

Provided is a formation method of a secondary battery, more particularly, to a method for removing gas generated during formation process of a secondary battery. The formation method includes a pre formation operation for pre-charging a pouch-type secondary battery in which an electrode assembly and an electrolyte are sealed, the pouch-type secondary battery including a pocket for gas collection; a primary degassing operation for forming a piercing in the pocket for gas collection, primarily degassing the gas generated during the pre-formation operation in real time through the piercing, and then sealing the piercing; and a secondary degassing operation for aging and secondarily degassing the pre-formed secondary battery.