Prismatic Winding Core Geometry for Faster Li-Ion Transport
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Solution Overview
Problem
The mismatch between the core forming structure and the transmission rate of Li ions in lithium-ion batteries results in slow ion transmission, affecting overall rate performance and energy density, and poses safety risks due to excessive compression or insufficient swelling.
Innovation Solution
A quadrangular prismatic battery design with controlled ratios of corner region to middle region areas (0.015≤2a2/dh≤0.1) ensures appropriate compression and ion transmission, preventing issues like slow ion transmission, poor energy density, and safety hazards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the winding core is subjected to thermoforming with uniform compression, then the structural integrity is improved, but the Li ion transmission rate deteriorates due to excessive compression in certain regions
Solution Approach 1:
The patent applies different compression forces to different regions of the winding core during thermoforming. Specifically, the corner regions receive a first compression force while the middle region receives a second compression force, creating a non-uniform compression distribution that adapts to the local structural needs of each region.
Solution Approach 2:
The patent divides the winding core into distinct regions (corner regions and middle region) and applies independent compression control to each segment. This segmentation allows for optimized compression parameters in each zone, preventing excessive compression in corners while ensuring adequate structural integrity.
2Stability of the object's composition
If the corner regions are compressed more to improve structural stability, then the shape stability is improved, but the energy density deteriorates due to reduced swelling capacity
Solution Approach 1:
The patent implements region-specific compression where corner regions are compressed with a first force and the middle region with a second force. This local differentiation maintains shape stability in corners while preserving the swelling capacity and energy density in the middle region where active materials are concentrated.
Solution Approach 2:
The patent changes the compression force parameter across different regions of the winding core. By adjusting the compression force from uniform to non-uniform distribution, the patent simultaneously achieves shape stability and maintains energy density through optimized local parameters.
3Ease of manufacture
If the middle region is compressed uniformly with corner regions, then the manufacturing process is simplified, but the Li ion transmission deteriorates due to mismatched compression rates
Solution Approach 1:
The patent implements differentiated compression for the middle region versus corner regions during thermoforming. The middle region receives a second compression force that differs from the first compression force applied to corner regions, optimizing Li ion transmission pathways while maintaining manufacturing feasibility.
Data Source
AI summary
A single battery, a battery apparatus, and a power consumption apparatus are provided. The single battery includes a casing having an accommodating cavity and at least one winding core accommodated in the accommodating cavity. The winding core includes a positive electrode piece, a negative electrode piece, and a separator. After being laminated, the winding core is formed with flat surfaces opposite to each other and corner regions connected to two sides of the opposite flat surfaces. A distance between the flat surfaces opposite to each other is h. Four endpoints connecting the opposite flat surfaces and the corner regions and the opposite flat surfaces surround and form a middle region. The middle region has a rectangular structure. A length of the middle region in a winding direction is d, and a maximum thickness of each of the corner regions in the winding direction is a, where 0.015≤2a2/dh≤0.1.