Lithium Battery Electrode Grooves for Uniform Electrolyte Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In lithium secondary batteries, high active material filling densities lead to difficulties in impregnating nonaqueous electrolytes, resulting in nonuniform distribution and reduced capacity, while forming grooves for improved impregnation can cause electrode plate deformation and internal short circuits.
Innovation Solution
The electrode plate design features grooves only on both-surface coated parts, not on one-surface coated parts, to reduce tensile stress and prevent deformation, with a porous protective film to enhance electrolyte impregnation and prevent internal short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the filling density of active material in electrode plates is increased to increase battery capacity, then the capacity is improved, but the ability to impregnate nonaqueous electrolyte into the electrode group is reduced and the distribution becomes nonuniform
Solution Approach 1:
The electrode plate surface is segmented into multiple grooves that divide the active material layer into separate regions. This segmentation creates multiple electrolyte infiltration pathways, allowing electrolyte to reach deep into the high-density active material from multiple points simultaneously, thereby improving distribution uniformity while maintaining high filling density
Solution Approach 2:
The grooves create a porous structure on the electrode plate surface that facilitates electrolyte penetration. The groove geometry (width, depth, spacing) is optimized to provide sufficient porosity for electrolyte flow while maintaining high active material density in the bulk, resolving the contradiction between density and impregnation ability
2Reliability
If grooves are formed in the active material layer to improve electrolyte impregnation, then the impregnation ability is improved, but the electrode plate may fracture during winding
Solution Approach 1:
The grooves are designed with specific local characteristics including optimized width, depth, and spacing parameters. The groove dimensions are carefully controlled to provide sufficient electrolyte access while maintaining structural integrity. The grooves are formed only in specific regions of the electrode plate where they provide maximum benefit without compromising overall strength
Solution Approach 2:
The electrode plate structure combines the grooved active material layer with the underlying current collector and surrounding active material matrix. This composite structure provides mechanical support to the grooved regions, preventing fracture during winding while maintaining the electrolyte impregnation benefits of the groove structure
3Reliability
If grooves are formed in the active material layer to improve electrolyte distribution, then the impregnation uniformity is improved, but the amount of active material is reduced causing capacity loss
Solution Approach 1:
The grooves are designed to occupy only a small fraction of the total electrode plate area (partial action), sufficient to provide effective electrolyte distribution pathways without significantly reducing the active material volume. The groove spacing and dimensions are optimized to achieve the minimum necessary groove coverage for effective impregnation while maximizing active material retention
Solution Approach 2:
The groove parameters (width, depth, spacing, orientation) are carefully controlled and optimized to minimize active material removal while maximizing electrolyte access. By adjusting these parameters, the design achieves effective impregnation with minimal impact on active material quantity, thereby maintaining high capacity
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 improves electrolyte impregnation, prevents electrode plate deformation, and enhances battery reliability and productivity by maintaining uniform electrolyte distribution and preventing internal short circuits.
Implementation Method 1
a porous protective film is formed on the active material layer... improves impregnation of the nonaqueous electrolyte
Implementation Method 2
grooves are formed in surfaces of both-surface coated parts... improves impregnation of the nonaqueous electrolyte with a relatively high viscosity
Data Source
AI summary
In an electrode plate 3 including a both-surface coated part 14 in which an active material layer 13 and a porous protective film 28 are formed, a core material exposed part 18 which is an end part of the current collector core material 12 and in which the active material layer 13 and the porous protective film 28 are not formed, and a one-surface coated part 17 which is provided between the both-surface coated part 14 and the core material exposed part 18 and in which the active material layer 13 and the porous protective film 28 are formed, a plurality of grooves 10 are formed in both surfaces of the both-surface coated part 14 and are not formed in the one-surface coated part 17. The grooves 10 are formed so that each of the grooves extends from the porous protective film 28 to the active material layer 13.