Cathode Pole Piece Broken Portions to Suppress Lithium Plating

Solution Overview

Problem

Lithium batteries face issues with lithium precipitation during charging, leading to reduced charging efficiency, energy density, and potential safety hazards due to lithium ions not being able to intercalate evenly into the negative electrode active material layer, causing short-circuiting.

Innovation Solution

A cell design with a cathode pole piece featuring broken portions in the bent areas, reducing the amount of lithium ions that can de-intercalate and thus minimizing lithium precipitation, combined with a manufacturing apparatus that forms and winds these broken portions to ensure proper alignment and material distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the cathode pole piece is continuous without broken portions, then the battery capacity is maximized, but lithium precipitation occurs during charging

Engineering Contradiction:

Improvebattery capacityVSAvoidlithium precipitation prevention

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The cathode pole piece is divided into multiple sections by introducing broken portions at regular intervals along its length. These broken portions create discrete active material segments that control lithium ion de-intercalation rates, preventing localized precipitation while preserving overall capacity through the cumulative effect of multiple segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The broken portions are strategically positioned at specific locations along the cathode pole piece to create local variations in lithium ion transport. This local modification allows different regions to have optimized characteristics for preventing precipitation while maintaining overall battery performance.

Inventive Principle:

Principle #3Local quality

2Reliability

If broken portions are introduced in the cathode pole piece, then lithium precipitation is suppressed, but the battery capacity is reduced

Engineering Contradiction:

Improvelithium precipitation preventionVSAvoidbattery capacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

Instead of making the cathode pole piece completely discontinuous, broken portions are introduced at optimized intervals that provide sufficient precipitation prevention while maintaining adequate active material coverage. The spacing and dimensions of broken portions are carefully controlled to achieve the minimum necessary intervention for reliability improvement.

Inventive Principle:

Principle #16Partial or excessive action

3Stability of the object's composition

If the cathode pole piece is made with broken portions, then material dislodgment in bent areas is prevented, but the manufacturing complexity increases

Engineering Contradiction:

Improvematerial retention in bent areasVSAvoidpole piece structure

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The cathode pole piece is divided into multiple sections by introducing broken portions at regular intervals along its length. These broken portions create discrete active material segments that control lithium ion de-intercalation rates, preventing localized precipitation while preserving overall capacity through the cumulative effect of multiple segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The broken portions are strategically positioned at specific locations along the cathode pole piece to create local variations in lithium ion transport. This local modification allows different regions to have optimized characteristics for preventing precipitation while maintaining overall battery performance.

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 suppresses lithium precipitation by reducing lithium ion intercalation imbalances and preventing material dislodgment, enhancing battery stability and safety while maintaining high manufacturing efficiency.

Implementation Method 1

When charging a lithium battery, lithium ions will de-intercalate from the positive electrode and intercalate into the negative electrode

Methodology Applied

Scientific EffectIntercalation: Absorption (physical)

Implementation Method 2

The lithium ions that cannot intercalate into the negative electrode active material layer can only obtain electrons on the surface of the negative electrode pole piece and generate silver-white metallic lithium, that is, leading to the phenomenon of lithium precipitation

Methodology Applied

Scientific EffectLithium precipitation: Precipitation

Data Source

PatentUS20240421360A1Cell, battery and cell manufacturing apparatus

Publication Date: 2024.12.19 WUXI LEAD INTELLIGENT EQUIP CO LTD

AI summary

The present disclosure relates to a cell. Since at least a portion of the cathode pole piece located in the bent areas is formed with a broken portion, there is no positive electrode active material layer and thus no lithium ions in the area corresponding to the broken portion, therefore, the amount of lithium ions that can de-intercalate from the cathode pole piece in the bent areas will be significantly reduced. In addition, the present disclosure also relates to a battery and a cell manufacturing apparatus.