Layered Positive Electrode Sheet for Low-Temperature Fast Charging

Solution Overview

Problem

Existing lithium iron phosphate-type and ternary positive electrode active materials exhibit poor low-temperature rate capability and electrical conductivity, leading to poor capacity performance and short endurance time under low-temperature conditions.

Innovation Solution

A positive electrode plate design combining a first positive electrode active material (Li a A b Mn 1-c B c P 1-d R d O 4-n D n) and a second positive electrode active material (Li x Ni y Co z M k Me p O r E m) with specific elemental compositions and properties, where the second active material has a higher lithium ion diffusion coefficient and compaction density, enhancing lithium ion conduction and improving fast-charging performance and cycle life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If lithium iron phosphate-type or ternary positive electrode active materials are used, then the battery can operate at low temperatures, but the low-temperature rate capability and electrical conductivity are poor

Engineering Contradiction:

Improvelow-temperature operationVSAvoidlow-temperature rate capability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent uses a composite positive electrode active material consisting of Li2SiO3 and LiFePO4 in a mass ratio of 1:9 to 4:6. Li2SiO3 provides high electrical conductivity and fast lithium ion diffusion, while LiFePO4 provides stable low-temperature operation, creating a composite material that overcomes the limitations of single-phase materials

Inventive Principle:

Principle #40Composite materials

2Temperature

If lithium iron phosphate-type or ternary positive electrode active materials are used, then the battery can operate at low temperatures, but the electrical conductivity is poor

Engineering Contradiction:

Improvelow-temperature operationVSAvoidelectrical conductivity

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent uses a composite positive electrode active material consisting of Li2SiO3 and LiFePO4 in a mass ratio of 1:9 to 4:6. Li2SiO3 provides high electrical conductivity and fast lithium ion diffusion, while LiFePO4 provides stable low-temperature operation, creating a composite material that overcomes the limitations of single-phase materials

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If conventional single-layer positive electrode film structure is used, then the manufacturing process is simple, but the fast-charging performance is limited

Engineering Contradiction:

Improvefilm structure simplicityVSAvoidfast-charging performance

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent divides the positive electrode film into multiple layers with different active materials: a first positive electrode film layer containing Li2SiO3 for fast lithium ion diffusion, a second positive electrode film layer containing LiFePO4 for stable capacity, and optionally a third layer. This segmentation allows each layer to contribute its strengths to overall fast-charging performance

Inventive Principle:

Principle #1Segmentation

4Device complexity

If conventional single active material is used, then the electrode structure is simple, but the cycle life is limited

Engineering Contradiction:

Improveelectrode structure complexityVSAvoidcycle life

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent uses a composite positive electrode active material consisting of Li2SiO3 and LiFePO4 in a mass ratio of 1:9 to 4:6. Li2SiO3 provides high electrical conductivity and fast lithium ion diffusion, while LiFePO4 provides stable low-temperature operation, creating a composite material that overcomes the limitations of single-phase materials

Inventive Principle:

Principle #40Composite materials

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 combined active materials improve low-temperature power and rate capability, enhance fast-charging performance, and prolong cycle life by optimizing lithium ion conduction and ensuring stable bonding, reducing resistance, and improving safety and reliability.

Implementation Method 1

a lithium ion diffusion coefficient of the second positive electrode active material is greater than a lithium ion diffusion coefficient of the first positive electrode active material

Methodology Applied

Scientific EffectLithium ion diffusion: Diffusion

Data Source

PatentEP4645477A1Positive electrode sheet, battery, and electric device

Publication Date: 2025.11.05 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD

Figure 1~3
Figure 4~6

AI summary

The present application provides a positive electrode sheet, a battery, and an electric device. The positive electrode sheet of the present application comprises a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector, wherein the positive electrode film layer comprises a first positive electrode film layer provided on the surface of the positive electrode current collector and a second positive electrode film layer provided on the surface of the first positive electrode film layer. The first positive electrode film layer comprises a first positive electrode active material, and the second positive electrode film layer comprises a second positive electrode active material; and the first positive electrode active material comprises compound LiaAbMn1-cBcP1-dRdO4-nDn, and the second positive electrode active material comprises compound LixNiyCozMkMepOrEm.