Dual-Layer Negative Electrode Plate for Battery Energy Density

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Solution Overview

Problem

Current traction batteries face challenges in achieving both high energy density and dynamic performance without compromising long-term reliability and power performance, as increasing energy density often deteriorates these aspects.

Innovation Solution

A negative electrode plate with a dual-layer structure, where the first layer has a Young's modulus of 1-10 GPa and the second layer has a Young's modulus of 11-30 GPa, ensuring consistent pressure and porosity for effective electrolyte infiltration and ion transmission, thereby enhancing cycling and dynamic performance without sacrificing energy density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If coating weight is increased to increase energy density, then energy density is improved, but power performance and long-term reliability deteriorate

Engineering Contradiction:
Improveenergy densityVSAvoidpower performance and long-term reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The negative electrode active substance layer is divided into two distinct layers: a first layer with lower Young's modulus (1-10 GPa) and a second layer with higher Young's modulus (11-30 GPa). This segmentation allows each layer to perform different functions - the first layer maintains porosity and electrolyte infiltration while the second layer provides structural stability and consistent pressure, thereby achieving both high energy density and reliable power performance without increasing coating weight

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a composite structure combining two different negative electrode active substances with different mechanical properties (Young's modulus values). This composite approach allows the electrode to simultaneously exhibit the porosity and electrolyte retention characteristics of the first material and the structural stability and pressure consistency of the second material, resolving the contradiction between energy density and power performance

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If coating weight is increased to increase energy density, then energy density is improved, but dynamic performance deteriorates

Engineering Contradiction:
Improveenergy densityVSAvoiddynamic performance
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

By dividing the electrode into two layers with different mechanical properties, the first layer maintains high porosity for fast ion diffusion while the second layer ensures consistent pressure distribution. This segmentation enables the electrode to achieve both high energy density and excellent dynamic performance without increasing coating weight

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the electrode (first layer vs. second layer) are assigned different mechanical properties tailored to their specific functions. The first layer is designed with lower Young's modulus to maintain porosity and facilitate ion transport, while the second layer has higher Young's modulus to provide structural support and pressure consistency, thereby optimizing both energy density and dynamic performance

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS11721811B2Negative electrode plate and secondary battery
Publication Date: 2023.08.08 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

AI summary

The present application relates to the electrochemical field, and in particular, to a negative electrode plate and a secondary battery including the electrode plate. The present application provides a negative electrode plate. The negative electrode plate includes a negative electrode current collector, a first negative electrode active substance layer disposed on at least one surface of the negative electrode current collector, and a second negative electrode active substance layer disposed on the first negative electrode active substance layer. The first negative electrode active substance layer includes a first negative electrode active substance, and the second negative electrode active substance layer includes a second negative electrode active substance. The first negative electrode active substance satisfies 1 GPa≤Young's modulus≤10 GPa, and the second negative electrode active substance satisfies 11 GPa≤Young's modulus≤30 GPa.