Secondary Battery Anode Crosslinking to Prevent Electrode Spring Back

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Solution Overview

Problem

The spring back phenomenon during the manufacturing of secondary battery electrodes leads to increased thickness, which affects the volume of the final battery cell and can cause damage or deterioration in manufacturing processability.

Innovation Solution

Incorporating a thermal crosslinking additive, such as epoxy-based, borate-based, or thiol-based compounds, into the anode mixture layer to enhance adhesion and alleviate stress, thereby preventing the spring back phenomenon and improving manufacturing processability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the electrode thickness is reduced to secure high energy density, then the energy density is improved, but the spring back phenomenon occurs causing thickness increase during manufacturing

Engineering Contradiction:
Improveenergy densityVSAvoidelectrode thickness control
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by incorporating a thermal crosslinking additive into the binder before the electrode manufacturing process. This additive undergoes thermal crosslinking during the drying and rolling process, creating a pre-strengthened binder structure that prevents spring back phenomenon before it occurs, thereby maintaining precise thickness control even when electrode thickness is reduced for high energy density

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the chemical parameter of the binder by introducing a thermal crosslinking additive that undergoes crosslinking reactions at elevated temperatures. This parameter change transforms the binder from a simple adhesive to a crosslinked network structure, fundamentally altering its mechanical properties to resist thickness increase during manufacturing while enabling thinner electrodes for higher energy density

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the electrode thickness is reduced to improve energy density, then the energy density is improved, but damage to the electrode occurs during manufacturing

Engineering Contradiction:
Improveenergy densityVSAvoidelectrode integrity
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The thermal crosslinking additive performs preliminary strengthening of the binder structure during the drying and rolling process. This pre-formed crosslinked network provides mechanical support to the thin electrode structure, preventing damage during subsequent handling and assembly operations while enabling the use of thinner electrodes for higher energy density

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a composite binder system combining the base binder with thermal crosslinking additives. This composite material exhibits enhanced mechanical strength and structural stability compared to the pure binder, providing necessary support for thin electrodes to maintain integrity during manufacturing while enabling reduced thickness for improved energy density

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If the electrode thickness is reduced to improve energy density, then the energy density is improved, but manufacturing processability deteriorates

Engineering Contradiction:
Improveenergy densityVSAvoidmanufacturing processability
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The thermal crosslinking additive undergoes parameter change through thermal crosslinking reactions during manufacturing, transforming the binder properties in situ. This dynamic parameter change provides progressive strengthening as the electrode is processed, maintaining ease of manufacture during initial stages while preventing spring back and damage in subsequent stages, thereby enabling thin electrode production for high energy density

Inventive Principle:
Principle #35Parameter changes

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 use of thermal crosslinking additives improves electrode adhesion, reduces electrode thickness variation, and enhances the energy density of the secondary battery by maintaining the designed thickness and reducing the risk of damage during the manufacturing process.

Implementation Method 1

the anode mixture layer includes an anode active material, a binder, and a thermal crosslinking additive

Methodology Applied
Scientific EffectThermal crosslinking:

Data Source

PatentEP4625548A1Anode for secondary battery and lithium secondary battery including the same
Publication Date: 2025.10.01 SK ON CO LTD
  • EP4625548A1 patent drawingFigure 1
  • EP4625548A1 patent drawingFigure 2
  • EP4625548A1 patent drawingFigure 3

AI summary

According to an embodiment, an anode for a secondary battery includes: an anode current collector; and an anode mixture layer on at least one surface of the anode current collector, wherein the anode mixture layer includes an anode active material, a binder, and a thermal crosslinking additive, and a weight of the binder included in the anode mixture layer is greater than a weight of the thermal crosslinking additive included in the anode mixture layer. According to an embodiment of the disclosed technology, energy density of the anode for a secondary battery may be improved.