Electrode Assembly Coating Layout for Stable Lithium Supplementation

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Solution Overview

Problem

Existing battery technologies face challenges in maintaining stable capacity due to lithium ion depletion during the formation of a solid electrolyte film, leading to irreversible capacity loss, lithium precipitation, and uneven lithiation, which affects battery performance and safety.

Innovation Solution

An electrode assembly with a first current collector having a first coating region for active substance material and a second coating region for lithiation material, separated by a gap, which releases lithium ions to the electrolyte during charge and discharge, preventing lithium precipitation and ensuring sufficient lithium intercalation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If lithiation material is directly contacted with active substance material to supplement lithium ions, then lithium ion supplementation effect is improved, but lithium precipitation and uneven lithiation occur

Engineering Contradiction:

Improvelithium ion supplementationVSAvoidlithium precipitation and uneven lithiation

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The current collector is divided into distinct coating regions: a first coating region for active substance material and a second coating region for lithiation material, separated by a gap. This segmentation prevents direct contact between lithiation material and active substance material, avoiding lithium precipitation while maintaining effective lithium ion supplementation to the electrolyte.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The electrolyte serves as an intermediary medium between the lithiation material and the active substance material. The lithiation material releases lithium ions into the electrolyte, which then transport these ions to the active substance material, preventing direct contact and associated problems while ensuring uniform lithium distribution.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If lithiation material is coated on the extension portion of the first current collector, then processing efficiency is improved, but lithium precipitation may occur if facing the second current collector

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidlithium precipitation

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The lithiation material is selectively coated on the extension portion of the first current collector in a controlled manner, creating a localized coating region that supplements lithium ions without facing the second current collector. This local quality control ensures processing efficiency while preventing lithium precipitation on the opposing electrode.

Inventive Principle:

Principle #3Local quality

3Reliability

If the first gap is entirely located in the extension portion, then lithium precipitation is avoided, but lithium intercalation positions may be insufficient

Engineering Contradiction:

Improvelithium precipitation preventionVSAvoidlithium intercalation positions

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The gap structure is configured in the extension portion of the current collector, utilizing the dimensional space available in the winding direction. This arrangement prevents direct facing between lithiation material and the second current collector (avoiding lithium precipitation) while still providing adequate lithium ion supplementation to the electrolyte for sufficient intercalation positions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 stabilizes battery capacity, improves lithiation efficiency, and enhances cycling performance by maintaining sufficient lithium ions in the electrolyte, reducing lithium precipitation and regional over-lithiation issues.

Implementation Method 1

the lithiation material in the second coating region can release lithium ions to electrolyte to make up for the lithium ions consumed during the forming of a solid electrolyte film

Methodology Applied

Scientific EffectIon release: Electrolysis

Implementation Method 2

lithium ions consumed during the forming of a solid electrolyte film

Methodology Applied

Scientific EffectFilm formation: Deposition (physical)

Implementation Method 3

uneven lithium intercalation caused by direct contact between the lithiation material and the active substance material

Methodology Applied

Scientific EffectIntercalation: Absorption (physical)

Data Source

PatentUS20230402580A1Electrode assembly, battery cell, battery, and electric apparatus

Publication Date: 2023.12.14 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

AI summary

An electrode assembly includes a current collector. The current collector includes a first coating region and a second coating region. The first coating region is coated with an active substance material and the second coating region is coated with a lithiation material. In an extension direction of the current collector, a gap is disposed between the first coating region and the second coating region.