Deformable Battery Central Tube for Electrode Stability
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Solution Overview
Problem
Cylindrical batteries, particularly those with a silicon negative-electrode system, face issues such as electrode sheet collapse at the central hole due to mismatched dimensions between the central tube and the central hole, leading to reduced service life and safety concerns, as well as hindered electrolyte infiltration and gas flow.
Innovation Solution
A battery central tube with deformable portions featuring foldable units that can expand or contract to fit snugly within the central bore, allowing for stable assembly and improved electrolyte infiltration and gas flow, utilizing materials like copper, aluminum-titanium alloy, or polypropylene, and incorporating a force-applying device for assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a fixed-diameter central tube is used in the battery, then the assembly process is simplified, but the outer wall of the central tube does not fit tightly to the inner wall of the central hole, causing collapse of the electrode sheet
Solution Approach 1:
The central tube employs a dynamic structure with foldable units that can transition between expanded and contracted states. During assembly, the foldable units are compressed to allow insertion, then expand automatically to achieve tight fitting against the central hole wall, eliminating the trade-off between ease of assembly and fitting tightness.
Solution Approach 2:
The diameter of the central tube is made variable through the foldable unit mechanism. The tube can change its outer diameter parameter from a contracted state (smaller diameter for easy insertion) to an expanded state (larger diameter for tight fitting), allowing the same structure to satisfy both assembly ease and fitting reliability requirements.
2Strength
If a rigid central tube is used to prevent collapse, then structural support is improved, but the tube wall hinders the infiltration of electrolyte and flow of internal gas
Solution Approach 1:
The central tube uses a flexible structure composed of foldable units that can deform and create gaps between the tube wall and electrode sheet. This flexibility allows electrolyte to infiltrate and gas to flow through the structure while the tube maintains its structural support function when expanded.
Solution Approach 2:
The foldable unit structure creates a porous-like configuration with gaps and channels between the folded segments. These spaces allow electrolyte infiltration and gas flow while the overall tube structure provides mechanical support, effectively resolving the contradiction between strength and permeability.
3Reliability
If the central tube outer wall is made larger to fit the central hole, then fitting tightness is improved, but the assembly process becomes more difficult due to deviation between tube diameter and hole dimension
Solution Approach 1:
The foldable units are pre-configured in a contracted state that allows easy insertion into the central hole, accommodating dimensional deviations. After insertion, the units expand to their operational configuration to achieve tight fitting, separating the insertion and fitting processes to reduce overall assembly complexity.
Solution Approach 2:
The dynamic expansion capability allows the tube to adapt to various hole dimensions. Rather than requiring precise dimensional matching during assembly, the tube can be inserted in a contracted state and then expand to fit the specific hole geometry, reducing assembly complexity while maintaining fitting reliability.
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 deformable central tube structure enhances battery performance by preventing electrode collapse, optimizing electrolyte and gas flow, extending cycle life, and reducing assembly complexity while maintaining a simple structure and lightweight design.
Implementation Method 1
an outer side of each of the at least one deformation portion has an expanded state and a contracted state, an outer wall of the deformation portion gets close to an inner wall of a central hole of a battery when the each of the at least one deformation portion is in the expanded state
Data Source
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AI summary
Disclosed are a battery central tube and a battery. The battery central tube includes: at least one deformation portion, wherein the at least one deformation portion is arranged in an annular shape, and an outer side of the at least one deformation portion is arranged to be expandable or contractible to get close to or away from an inner side of a winding core of the battery; wherein each of the at least one deformation portion includes several foldable units, the several foldable units are sequentially arranged along an annular direction of the each of the at least one deformation portion, and each of the foldable units is at least unfolded or folded and elongated or shortened along the annular direction of the deformation portion. The present invention achieves a light weight, and can improve the overall energy density of the battery to some extent.