Monocrystalline Battery Cell Geometry for Electrolyte Infiltration

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Solution Overview

Problem

Existing battery technologies face challenges in achieving high energy density and long cycle life, particularly due to issues with electrolyte solution infiltration and structural stability of lithium-containing transition metal oxides.

Innovation Solution

The battery cell design incorporates a positive electrode active material with layered lithium-containing transition metal oxide in monocrystalline morphology, optimized dimensions (length to width ratio of 2.0 to 10.5) and electrode assembly structures to enhance electrolyte infiltration and ion transmission, along with differential coating of negative electrode active materials to improve power performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the length of the battery cell is increased to improve energy density, then the mass ratio of active materials improves, but electrolyte solution infiltration becomes difficult especially in the central region

Engineering Contradiction:
Improvemass ratio of active materialsVSAvoidelectrolyte solution infiltration
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent optimizes the length-to-width ratio parameter within a specific range (2.0 to 10.5) to balance energy density and electrolyte infiltration. This parameter change allows the battery to achieve high active material content while maintaining adequate electrolyte distribution through controlled geometric proportions.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the length of the battery cell is increased to improve energy density, then the group margin improves, but the cycle life deteriorates due to poor electrolyte infiltration

Engineering Contradiction:
Improvegroup marginVSAvoidcycle life
Core Design Contradiction:
Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The patent establishes an optimal length-to-width ratio range (2.0 to 10.5) that simultaneously improves group margin and maintains cycle life. This parameter optimization ensures that even with increased cell length for higher energy density, the electrolyte can still adequately infiltrate the electrode assembly, preserving long-term cycling performance.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If conventional lithium-containing transition metal oxide is used, then the battery structure is simple, but structural stability deteriorates leading to capacity fade

Engineering Contradiction:
Improvebattery structureVSAvoidstructural stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent employs a composite structure of lithium-containing transition metal oxide with controlled morphology (aggregate of fine particles) that enhances structural stability while maintaining relative simplicity in the overall battery design. This composite approach prevents capacity fade through improved structural integrity during cycling.

Inventive Principle:
Principle #40Composite materials

4Quantity of substance

If the mass ratio of active materials is increased to improve energy density, then the volume utilization improves, but side reactions increase due to insufficient electrolyte infiltration

Engineering Contradiction:
Improvemass ratio of active materialsVSAvoidside reactions
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent controls the length-to-width ratio within the range of 2.0 to 10.5 to ensure adequate electrolyte infiltration throughout the electrode assembly. This parameter optimization allows high mass ratios of active materials to be utilized effectively while preventing insufficient electrolyte contact that would otherwise lead to increased side reactions and capacity degradation.

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

This design results in a battery with improved energy density and extended cycle life, facilitated by enhanced electrolyte infiltration and balanced structural stability, reducing side reactions and capacity fade.

Implementation Method 1

transmission of lithium ions is facilitated

Methodology Applied
Scientific EffectIon transmission: Diffusion

Implementation Method 2

electrolyte solution infiltration in an entire region of the electrode assembly including a central region can be further improved

Methodology Applied
Scientific EffectElectrolyte solution infiltration: Capillary Action

Data Source

PatentEP4672404A1Battery cell, battery, and electric apparatus
Publication Date: 2025.12.31 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP4672404A1 patent drawingFigure 1~2
  • EP4672404A1 patent drawingFigure 3~4
  • EP4672404A1 patent drawingFigure 5~6

AI summary

A battery cell, a battery, and a power consuming apparatus. The battery cell includes an electrode assembly and an outer package. The electrode assembly includes a positive electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector. The positive electrode film layer includes a positive electrode active material. The positive electrode active material includes layered lithium-containing transition metal oxide in monocrystalline morphology. A length of the battery cell is denoted as a, and a width of the battery cell is denoted as b. a is greater than or equal to 180 mm, and a/b ranges from 2.0 to 10.5. In this way, the battery can take into account high energy density and long cycle life.