Negative Electrode Plate Zoning for Lithium Plating Suppression

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Solution Overview

Problem

Lithium plating occurs in the non-overlapping region between the negative electrode and positive electrode plates during multiple charging and discharging cycles, leading to safety concerns for secondary batteries.

Innovation Solution

A negative electrode plate is designed with a current collector having distinct regions, where the first active layer with a higher specific surface area material is used in protruding regions to consume lithium ions rapidly, preventing plating, and the second active layer with a lower specific surface area material is used in overlapping regions to maintain lithium ion concentration and cycling stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a uniform active layer is used across the entire negative electrode plate, then the manufacturing process is simple, but lithium plating occurs in the non-overlapping region affecting safety

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidbattery safety

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by using different active materials with different specific surface areas in different regions of the negative electrode plate. The first active material with larger specific surface area is used in the non-overlapping region to prevent lithium plating, while the second active material with smaller specific surface area is used in the overlapping region. This regional differentiation resolves the contradiction by tailoring the electrode properties to the specific functional requirements of each region.

Inventive Principle:

Principle #3Local quality

2Reliability

If the first active material with larger specific surface area is used in the non-overlapping region, then lithium plating is prevented, but the lithium ion concentration decreases affecting cycling stability

Engineering Contradiction:

Improvebattery safetyVSAvoidcycling stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent resolves this contradiction by applying different active materials to different regions: the first active material with larger specific surface area is placed in the non-overlapping region to prevent lithium plating and ensure safety, while the second active material with smaller specific surface area is placed in the overlapping region to maintain lithium ion concentration and ensure cycling stability. Each region's material is optimized for its specific function.

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If the second active material with smaller specific surface area is used in the overlapping region, then cycling stability is maintained, but lithium ion extraction efficiency decreases

Engineering Contradiction:

Improvecycling stabilityVSAvoidlithium ion extraction efficiency

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent applies local quality by using the second active material with smaller specific surface area in the overlapping region where cycling stability is the priority, while the first active material with larger specific surface area is used in the non-overlapping region where lithium ion extraction efficiency is more critical for preventing plating. This regional optimization resolves the contradiction by matching material properties to regional functional requirements.

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 lithium plating while maintaining good cycling stability, thereby enhancing the performance and safety of secondary batteries.

Implementation Method 1

the specific surface area of the first active material is greater than that of the second active material... at the first active layer corresponding to the first region, the rate of consumption of lithium ions is high

Methodology Applied

Scientific EffectSpecific surface area effect: Adsorption

Implementation Method 2

In the process of charging and discharging a secondary battery, lithium ions are continuously extracted and inserted on a positive electrode and a negative electrode

Methodology Applied

Scientific EffectElectrochemical reaction: Redox Reactions

Data Source

PatentUS20250158078A1Negative electrode plate, secondary battery, battery module, battery pack, and electric device

Publication Date: 2025.05.15 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

AI summary

A negative electrode plate, including: a current collector and a first active layer provided on a surface of the current collector, where the first active layer includes a first active material and a second active material, the specific surface area of the first active material is greater than the specific surface area of the second active material, the current collector includes a first region and a second region which are arranged in a first direction, and the first active layer corresponding to the first region includes a first active material, and the first active layer corresponding to the second region includes a second active material, the first region being a region formed by the negative electrode plate protruding from a positive electrode plate in the first direction, and the second region being a region formed by the negative electrode plate overlapping with the positive electrode plate in the first direction.