Electrode Assembly Structure for Lithium-Ion Battery Deformation Control

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Solution Overview

Problem

Lithium-ion batteries deform during use due to electrode assembly deformation, leading to reduced packaging reliability and service life, which existing technologies fail to adequately address.

Innovation Solution

An electrochemical apparatus with a first electrode plate and a second electrode plate separated by a first separator with a polymer bonding layer on one surface and a second separator without a polymer bonding layer, utilizing the polymer bonding layer to shape and release stress, thereby inhibiting deformation and improving packaging reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a polymer bonding layer is applied to both separators, then bonding strength is improved, but material cost and gel formation increase

Engineering Contradiction:
Improvebonding strengthVSAvoidmaterial cost and gel formation
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The patent applies polymer bonding layers selectively only on the inner surfaces of separators that contact electrode plates, while outer surfaces remain without polymer bonding layers. This localized application provides bonding strength where needed (at electrode-separator interfaces) while reducing overall material usage and preventing gel formation from excessive polymer exposure to electrolyte.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If electrode assembly structure is simplified, then manufacturing ease is improved, but deformation resistance deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddeformation resistance
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent creates an asymmetric separator structure where inner surfaces have polymer bonding layers for strong electrode adhesion (preventing deformation) while outer surfaces lack polymer layers for simplified manufacturing and reduced complexity. This localized differentiation achieves both deformation resistance and manufacturing ease.

Inventive Principle:
Principle #3Local quality

3Strength

If polymer bonding layer area density is increased, then bonding strength is improved, but gel formation and material cost increase

Engineering Contradiction:
Improvebonding strengthVSAvoidgel formation
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The patent controls polymer bonding layer area density by applying it only to specific inner surfaces of separators rather than uniformly across all surfaces. This localized high-density application provides sufficient bonding strength at critical interfaces while reducing total polymer quantity, thereby minimizing gel formation from excess polymer-electrolyte interaction.

Inventive Principle:
Principle #3Local quality

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 solution effectively prevents deformation and enhances packaging reliability, reducing gel formation and extending the service life of lithium-ion batteries while minimizing material costs.

Implementation Method 1

at least one surface of the first porous substrate is provided with a polymer bonding layer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3910703B1Electrochemical apparatus and electronic apparatus
Publication Date: 2025.10.15 NINGDE AMPEREX TECHNOLOGY LTD
  • EP3910703B1 patent drawingFigure 1~2
  • EP3910703B1 patent drawingFigure 3~5
  • EP3910703B1 patent drawingFigure 6~7

AI summary

An electrochemical apparatus includes a first electrode plate, a second electrode plate, a first separator, and a second separator, the first separator includes a first porous substrate, the second electrode plate includes a second porous substrate, and the first electrode plate, the first separator, the second electrode plate and the second separator are stacked in sequence to form an electrode assembly; and at least one surface of the first porous substrate is provided with a polymer bonding layer, and at least one surface of the second porous substrate is provided with no polymer bonding layer. The electrode assembly structure separate a positive electrode plate and a negative electrode plate through a first separator provided with a polymer binder, which is beneficial to shape the electrode assembly and release a stress at corner, thereby inhibiting deformation of the electrochemical apparatus.