Grooved Negative Electrode Structure for Li-Ion Cycling Stability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium-ion batteries experience deformation and cycling degradation due to internal stress accumulation, leading to safety issues and reduced cycling stability, exacerbated by inadequate heat dissipation.

Innovation Solution

The electrode assembly design includes grooves on the negative electrode plate surface with specific width, spacing, and thickness adjustments to enhance the binding interface with the separator, using polymers and heat-resistant materials in the separator to increase binding force and mitigate deformation, thereby improving stability and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the electrode assembly thickness is increased to achieve higher energy density, then the specific energy is improved, but the internal stress accumulation and deformation are exacerbated

Engineering Contradiction:

Improvespecific energyVSAvoidcycling stability

Core Design Contradiction:

Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The negative electrode plate surface is segmented into multiple regions by grooves, creating distinct zones that can independently accommodate stress and deformation during cycling. This segmentation prevents uniform stress distribution that leads to deformation while maintaining overall electrode integrity and energy density.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The grooves create local variations in the electrode structure, with different regions having different mechanical properties. The groove regions provide stress relief zones while the inter-groove regions maintain active material density, achieving local optimization that resolves the contradiction between energy density and cycling stability.

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If the binding interface between the negative electrode plate and separator is strengthened to improve stability, then the deformation is reduced, but the device complexity increases

Engineering Contradiction:

Improvestability of negative electrode plateVSAvoidstructure complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The separator incorporates a porous coating layer that physically interlocks with the groove structures on the negative electrode plate. This porous structure provides mechanical anchoring without requiring complex external fastening mechanisms, thereby strengthening the binding interface while maintaining structural simplicity.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The separator is constructed as a composite structure with different layers having complementary functions: one layer provides porosity for mechanical interlocking with grooves, while another layer provides heat-resistant material for thermal stability. This composite approach achieves enhanced binding and stability without increasing overall device complexity.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS20260024749A1Secondary battery and electronic apparatus

Publication Date: 2026.01.22 NINGDE AMPEREX TECHNOLOGY LTD

AI summary

A secondary battery includes an electrode assembly. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The separator is disposed between the positive electrode plate and the negative electrode plate. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer. A surface of the negative electrode active material layer facing towards the positive electrode plate has grooves, a width of the groove is W mm, and a spacing of the grooves is S mm. A thickness of the electrode assembly is T1 mm, satisfying: W≥S×T1/1000.