Polygon Electrode Assembly in Cylindrical Battery Cells for Expansion Relief
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Solution Overview
Problem
The cycle life of battery cells is affected by performance attenuation due to excessive compression of electrode sheets, leading to issues like reduced porosity, material fracture, and difficulty in electrolyte infiltration, as the electrode assembly is locked against the housing, preventing stress release and causing performance degradation.
Innovation Solution
A battery cell design with a cylindrical housing and an electrode assembly projection that is a polygon along the height direction, allowing for expansion and maintaining a remaining space between the assembly and the housing, thereby preventing excessive compression and stress concentration, and utilizing a binding layer to maintain the assembly's shape and allow expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the electrode assembly is tightly fitted in the housing to improve energy density, then the space utilization is improved, but the electrode assembly cannot expand during charging and discharging, causing performance attenuation and reduced cycle life
Solution Approach 1:
The invention introduces a binding layer that segments the interaction between the electrode assembly and housing, allowing the assembly to expand independently within the binding layer while the housing maintains its structural form. This segmentation enables both tight fitting for energy density and expansion space for cycle life.
Solution Approach 2:
The binding layer acts as a flexible shell that wraps the electrode assembly, providing both constraint and flexibility. It allows the assembly to expand during charging and discharging while maintaining overall structural integrity and space utilization.
2Stability of the object's composition
If the electrode assembly is compressed to improve structural stability, then the structural integrity is improved, but the electrode sheet suffers from excessive compression causing material fracture and reduced porosity
Solution Approach 1:
The invention changes the compression parameter by introducing a binding layer with specific elastic properties. This layer provides gentle constraint that maintains structural stability while avoiding excessive compression that would damage the electrode sheet or reduce porosity.
Solution Approach 2:
The binding layer serves as a cushioning element between the electrode assembly and housing, preventing direct excessive compression. It absorbs and distributes expansion forces, protecting the electrode sheet from fracture while maintaining structural stability.
3Manufacturing precision
If the electrode assembly is constrained to maintain shape to improve manufacturing precision, then the shape control is improved, but the assembly cannot release stress causing performance degradation
Solution Approach 1:
The binding layer introduces dynamic characteristics to the system, allowing the electrode assembly to change shape during expansion while maintaining overall control. The layer adapts to volume changes, enabling both shape control for manufacturing precision and stress release for performance stability.
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 enhances the cycle life and energy density of the battery cell by preventing performance degradation, reducing material damage, and ensuring effective electrolyte infiltration, resulting in improved durability and longer service life.
Implementation Method 1
the binding layer has elasticity to allow the electrode assembly to expand
Data Source
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AI summary
Embodiments of the present application disclose a battery cell, a battery, a power consumption device, a method and an apparatus for producing a battery cell. The power consumption device is equipped with the battery, the battery has one or more battery cells, where the battery cell includes: a housing, with a cylindrical accommodating cavity; and an electrode assembly, arranged in the accommodating cavity, and a projection of the electrode assembly along a height direction of the battery cell is a polygon. Even if the electrode assembly in the battery cell expands after charging and discharging, there is still a remaining space between the electrode assembly and an inner wall of the housing, thereby preventing an outer circumferential surface of the electrode assembly from being pressed by the housing, and the remaining space can allow the electrode assembly to expand to avoid a problem of performance degradation of the battery cell caused by performance deterioration of an electrode sheet, such as drop of active materials, difficulty of infiltration of an electrolytic solution, and fracture of the electrode sheet due to excessive compression of the electrode sheet, thereby further alleviating a problem of the performance degradation of the battery cell affecting a cycle life of the battery cell.