Negative Electrode Layer Zoning for High-Density Secondary Batteries

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Solution Overview

Problem

Existing secondary batteries face challenges in simultaneously achieving high energy density and dynamic performance, as improving dynamic performance often compromises energy density.

Innovation Solution

A secondary battery design featuring a negative electrode plate with a specific structure, comprising a first carbon-based material with a pore structure in one area and a second carbon-based material with adjusted properties in another area, optimizing both energy density and dynamic performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the negative electrode film layer uses high compacted density material to improve energy density, then the energy density increases, but the volume change and particle damage increase, reducing safety performance and cycling performance

Engineering Contradiction:

Improveenergy densityVSAvoidsafety performance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The negative electrode film layer is divided into two distinct areas: a first area with high compacted density material for energy density, and a second area with low compacted density material with pore structure for safety and cycling performance. This segmentation allows each area to fulfill its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the negative electrode film layer are assigned different material properties: the first area uses material with high compacted density (1.6-2.0 g/cm³) for energy density, while the second area uses material with low compacted density (0.8-1.4 g/cm³) and pore structure for buffering volume expansion and reducing particle damage.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If the negative electrode film layer uses high compacted density material to improve energy density, then the energy density increases, but the dynamic performance deteriorates due to reduced active ion transport

Engineering Contradiction:

Improveenergy densityVSAvoiddynamic performance

Core Design Contradiction:

Quantity of substanceVSSpeed

Solution Approach 1:

The negative electrode film layer is segmented into a first area with high compacted density material for energy density and a second area with low compacted density material containing pore structures for active ion transport. This segmentation enables both high energy density and good dynamic performance to coexist.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second area incorporates material with pore structures that facilitate active ion transport, compensating for the reduced ion transport capability in the high compacted density first area. The pore structures provide channels for ion diffusion while maintaining structural integrity.

Inventive Principle:

Principle #31Porous materials

3Quantity of substance

If the negative electrode film layer uses material with high compacted density to improve energy density, then the volume change increases during charging-discharging, reducing cycling performance

Engineering Contradiction:

Improveenergy densityVSAvoidcycling performance

Core Design Contradiction:

Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The negative electrode film layer is divided into a first area with high compacted density material for energy density and a second area with low compacted density material for buffering volume expansion. This segmentation allows the battery to achieve high energy density while maintaining good cycling performance through the volume-buffering capability of the second area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second area with pore structures and low compacted density material acts as a pre-designed cushioning zone that accommodates volume expansion of the first area during charging-discharging cycles, preventing particle damage and maintaining structural integrity over extended cycling.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS20250105292A1Secondary battery and power consuming device

Publication Date: 2025.03.27 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

AI summary

The present application provides a secondary battery and a power consuming device. The secondary battery comprises a negative electrode plate, wherein the negative electrode plate comprises a negative electrode current collector and a negative electrode film layer formed on at least one surface of the negative electrode current collector, the negative electrode film layer has a first surface away from the negative electrode current collector and a second surface opposite to the first surface; the first area comprises a first active material, the first active material comprises a first carbon-based material, and the first carbon-based material has a pore structure; and the second area comprises a second active material, and the second active material comprises a second carbon-based material. The present application enables the secondary battery to have not only a high energy density but also high safety performance, and good dynamic performance, cycling performance and storage performance.