Negative Electrode Particle Grading for Better Lithium-Ion Migration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithium secondary batteries face challenges in achieving improved life and performance due to heterogeneous particle size distributions in the negative electrode active material layers, which inhibit lithium ion migration and react differently with the electrolyte solution.
Innovation Solution
The negative electrode active material layer is designed with two or more types of materials having different D50 values, optimized to satisfy specific particle size distribution criteria, ensuring uniform pore structures and controlled reactivity, thereby enhancing lithium ion migration and battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heterogeneous particle size distribution is used in the negative electrode active material layer, then manufacturing complexity is reduced, but lithium ion migration is inhibited and battery life is reduced
Solution Approach 1:
The patent applies local quality by creating distinct first and second regions within the negative electrode active material layer, each with different particle size distributions. The first region (closer to current collector) has a different D50 value than the second region (closer to electrolyte contact surface), optimizing lithium ion migration pathways while maintaining manufacturing feasibility through controlled heterogeneity rather than complete uniformity
Solution Approach 2:
The patent changes the particle size distribution parameter across different regions of the electrode layer. By specifying different D50 values for the first and second regions and controlling their ratios, the invention optimizes both lithium ion migration and electrolyte reactivity without requiring completely uniform particle sizes throughout the entire layer, thus balancing performance with manufacturing complexity
2Productivity
If uniform pore structure is achieved through controlled particle size distribution, then lithium ion migration is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent segments the negative electrode active material layer into a first region and a second region with different particle size characteristics. This segmentation allows each region to contribute differently to pore structure formation, creating an optimized overall pore network for lithium ion migration while distributing manufacturing precision requirements across two controllable parameters (D50 values and their ratio) rather than requiring uniform control of a single parameter throughout the entire layer
3Reliability
If controlled reactivity with electrolyte solution is achieved, then battery life is extended, but device complexity increases
Solution Approach 1:
The patent applies local quality by assigning different particle size distributions to different regions of the electrode layer. The first region's particle characteristics control reactivity at the current collector interface, while the second region's characteristics control reactivity at the electrolyte contact surface, allowing optimized and controlled reactivity throughout the layer without requiring complex multi-material compositions
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 design optimizes the pore structure and reactivity in the negative electrode, leading to improved lithium ion migration and extended battery life while maintaining high energy density.
Implementation Method 1
it is possible to improve not only migration of lithium ions but also reactivity between the negative electrode and an electrolyte solution including lithium
Implementation Method 2
reactivity between the negative electrode and an electrolyte solution including lithium, realizing long life performance of the battery
Data Source
AI summary
A negative electrode for a secondary battery includes a current collector and a negative electrode active material layer provided on at least one surface of the current collector. The negative electrode active material layer includes a first region corresponding to 50% of a total thickness of the negative electrode active material layer from a surface facing the current collector and a second region corresponding to 50% of the total thickness of the negative electrode active material layer from a surface opposite to the surface facing the current collector. The negative electrode active material layer includes two or more types of negative electrode active materials having D50 different from each other and satisfies the Equations 1 and 2. A secondary battery including the negative electrode is also provided.