Layered Graphite Negative Electrode for Battery Cycle and Load Performance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nonaqueous electrolyte secondary batteries face challenges in improving discharge load characteristics and long-term cycle characteristics, with carbon-coated graphite degrading adhesive and conductive properties, and soft graphite particles leading to decreased lithium ion diffusion and output characteristics.
Innovation Solution
A negative electrode with a two-layer structure, comprising a carbon-coated graphite first mixture layer at the surface and a non-coated graphite second mixture layer at the collector side, maintaining adhesive and conductive properties while enhancing lithium ion diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If graphite is coated with amorphous carbon to improve adhesive and conductive properties, then adhesive strength and electrical conductivity are improved, but lithium ion diffusion characteristics and output characteristics deteriorate
Solution Approach 1:
The patent applies local quality by creating a two-layer structure where the surface layer (first mixture layer) contains amorphous carbon-coated graphite for high lithium ion diffusion, while the base layer (second mixture layer) contains non-coated graphite for strong adhesion and conductivity. Each layer has different properties optimized for its specific function, resolving the contradiction between adhesive strength and lithium ion diffusion.
Solution Approach 2:
The negative electrode mixture layer is segmented into two distinct layers: a first mixture layer at the surface primarily composed of amorphous carbon-coated graphite, and a second mixture layer at the collector side primarily composed of non-coated graphite. This segmentation allows each layer to independently fulfill its specific function without compromising the other.
2Reliability
If graphite is coated with amorphous carbon to improve electrical conductivity, then electrical conductivity is improved, but discharge load characteristics deteriorate
Solution Approach 1:
The patent applies local quality by creating a two-layer structure where the surface layer (first mixture layer) contains amorphous carbon-coated graphite for high lithium ion diffusion, while the base layer (second mixture layer) contains non-coated graphite for strong adhesion and conductivity. Each layer has different properties optimized for its specific function, resolving the contradiction between adhesive strength and lithium ion diffusion.
Solution Approach 2:
The negative electrode mixture layer is segmented into two distinct layers: a first mixture layer at the surface primarily composed of amorphous carbon-coated graphite, and a second mixture layer at the collector side primarily composed of non-coated graphite. This segmentation allows each layer to independently fulfill its specific function without compromising the other.
3Reliability
If soft graphite particles are used to improve adhesive properties, then adhesive strength is improved, but lithium ion diffusion and output characteristics deteriorate
Solution Approach 1:
The patent applies local quality by creating a two-layer structure where the surface layer (first mixture layer) contains amorphous carbon-coated graphite for high lithium ion diffusion, while the base layer (second mixture layer) contains non-coated graphite for strong adhesion and conductivity. Each layer has different properties optimized for its specific function, resolving the contradiction between adhesive strength and lithium ion diffusion.
Solution Approach 2:
The negative electrode mixture layer is segmented into two distinct layers: a first mixture layer at the surface primarily composed of amorphous carbon-coated graphite, and a second mixture layer at the collector side primarily composed of non-coated graphite. This segmentation allows each layer to independently fulfill its specific function without compromising the other.
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
This configuration achieves excellent discharge load and long-term cycle characteristics by maintaining adhesive and conductive properties while ensuring effective lithium ion diffusion, resulting in improved battery performance.
Implementation Method 1
the surfaces of which are coated with an amorphous carbon
Implementation Method 2
the surfaces of which are coated with an amorphous carbon
Implementation Method 3
decreased diffusion property of lithium ions in the negative electrode mixture layer
Data Source
AI summary
The present disclosure aims to provide a nonaqueous electrolyte secondary battery having excellent discharge load characteristics and excellent long-term cycle characteristics. A nonaqueous electrolyte secondary battery which is one example of an embodiment of the present disclosure includes a positive electrode, a negative electrode (30), separators, and a nonaqueous electrolyte. The negative electrode (30) includes a negative electrode collector (31) and a negative electrode mixture layer (32) formed on the negative electrode collector (31). The negative electrode mixture layer (32) includes a first mixture layer primarily composed of a carbon-coated graphite (35) and a second mixture layer (34) primarily composed of a graphite (36), the first mixture layer (33) is disposed at a surface side of the negative electrode mixture layer (32), and the second mixture layer (34) is disposed at a side of the negative electrode collector (31).