Battery Cell Buffer Structure for Bent Electrode Swelling
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Solution Overview
Problem
Lithium precipitation in electrode assemblies of batteries during charge-discharge cycles affects the service life and cycling performance of electric vehicles.
Innovation Solution
A battery cell design incorporating an insulating member with an insulator and a first buffer body that wraps the electrode assembly, where the buffer body is positioned between the bent portion and the housing to mitigate swelling, reducing the risk of lithium precipitation and electrolyte bridge breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electrode assembly is allowed to swell freely during charge-discharge cycles, then the battery structure remains simple, but lithium precipitation occurs and service life is reduced
Solution Approach 1:
A buffer body is introduced as an intermediary component between the electrode assembly and the housing. This buffer body absorbs the swelling force of the electrode assembly during charge-discharge cycles, preventing direct contact and damage between the electrode assembly and housing. The buffer body acts as a mediator that resolves the conflict between allowing natural swelling and preventing damage, thereby extending service life without significantly complicating the overall structure.
Solution Approach 2:
The buffer body is pre-installed between the electrode assembly and the housing before the electrode assembly undergoes swelling during operation. This beforehand cushioning prepares the system to absorb swelling forces before they cause damage, preventing lithium precipitation and electrolyte bridge breakage that would otherwise occur during normal charge-discharge cycles.
2Reliability
If the bent portion of the electrode assembly is constrained to prevent swelling, then lithium precipitation is reduced, but the risk of electrolyte bridge breakage increases
Solution Approach 1:
The buffer body serves as an intermediary that allows the bent portion to swell naturally while preventing direct contact with the housing. This intermediary approach maintains the electrolyte bridge integrity by absorbing swelling forces without creating excessive constraint, thereby improving cycling performance while minimizing the risk of electrolyte bridge breakage.
Solution Approach 2:
The buffer body changes its physical parameters (compression, deformation) in response to the swelling of the bent portion. By dynamically adjusting its state based on the swelling pressure, the buffer body provides adaptive constraint that prevents lithium precipitation while avoiding excessive force that could break the electrolyte bridge.
3Reliability
If no insulation is provided between the electrode assembly and housing, then the device complexity is minimized, but short circuit risk increases
Solution Approach 1:
The buffer body performs multiple functions simultaneously: it provides mechanical cushioning against swelling forces and provides electrical insulation between the electrode assembly and housing. This multi-functionality achieves short circuit prevention without adding separate insulation components, thereby improving reliability while minimizing the increase in device complexity.
Solution Approach 2:
The insulation function is merged with the cushioning function in a single component - the buffer body. Instead of having separate insulation layers and buffer structures, the buffer body is designed to provide both mechanical protection against swelling and electrical insulation, simplifying the overall structure while achieving both safety objectives.
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 design enhances the cycling performance and extends the service life of the battery by effectively buffering the swelling force of the electrode assembly, reducing the risk of short circuits and improving the reliability of the battery cell.
Implementation Method 1
the first buffer body undergoes elastic deformation. The elastic deformation of the first buffer body can buffer the swelling of the bent portion of the electrode assembly
Data Source
AI summary
A battery cell, a battery, and an electric apparatus are disclosed. The battery cell includes a housing, an insulating member, and an electrode assembly arranged in a mounting cavity of the housing. The insulating member includes an insulator and a first buffer body connected together. The insulator surrounds the electrode assembly, which includes a body portion and a bent portion connected to an end of the body portion. The first buffer body is positioned between the bent portion and the housing to mitigate swelling forces at the bent portion. This configuration reduces the risk of excessive spacing between the negative and positive electrode plates, decreases the likelihood of electrolyte bridge breakage, alleviates lithium precipitation at the bent portion, and improves the cycling performance and service life of the battery cell.