Battery Cell Buffering Structure for Electrode Expansion Control
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Solution Overview
Problem
Existing battery cell technologies face challenges in improving cycling performance due to issues like uneven force distribution, electrode plate wrinkling, and increased expansion forces during charging and discharging.
Innovation Solution
Incorporating a compressible buffering member within the battery cell shell, which limits electrode assembly deformation during initial charging, improves force distribution uniformity, reduces wrinkling risks, and provides space for electrode expansion, thereby enhancing cycling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If no buffering member is provided, then the structure is simple and energy density is high, but the electrode assembly deforms excessively during charging causing wrinkling and poor cycling performance
Solution Approach 1:
A buffering member is introduced as an intermediary element between the electrode assembly and the shell. This buffering member absorbs expansion forces during charging cycles, preventing direct contact and mechanical damage between the electrode assembly and the rigid shell, thereby improving cycling performance without significantly complicating the overall structure.
2Reliability
If a buffering member is added, then cycling performance improves, but the energy density decreases due to additional material usage
Solution Approach 1:
The dimensions of the buffering member are precisely controlled within specific ranges (length 5-20mm, width 2-10mm, thickness 1-5mm) to optimize the balance between cycling performance improvement and energy density maintenance. By adjusting these parameters, the buffering member provides sufficient protection while minimizing space occupation.
3Reliability
If the buffering member is too large, then it provides sufficient protection against deformation, but it occupies excessive space reducing energy density
Solution Approach 1:
Specific dimensional parameters of the buffering member are optimized to provide adequate protection while minimizing volume. The length is controlled at 5-20mm, width at 2-10mm, and thickness at 1-5mm, ensuring sufficient mechanical protection without excessive space occupation.
4Use of energy by moving object
If the buffering member is too small, then energy density is improved, but the electrode assembly is insufficiently protected causing wrinkling
Solution Approach 1:
Minimum dimensional thresholds are established for the buffering member (length ≥5mm, width ≥2mm, thickness ≥1mm) to ensure adequate protection against electrode assembly deformation and wrinkling while maintaining acceptable energy density levels.
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 buffering member effectively reduces the action force between the shell and the electrode assembly, extends the service life of the electrode assembly, and improves the overall cycling performance of the battery cell by optimizing the dimensions and placement of the buffering member.
Implementation Method 1
During the cycling of the battery cell, the buffering member is compressed when squeezed by the electrode assembly, so as to provide space for the expansion of the electrode assembly, thereby reducing the action force between the shell and the electrode assembly
Implementation Method 2
The buffering member is configured to be compressible, and the sum of the dimensions of N buffering members along the first direction in an uncompressed state is D3
Data Source
AI summary
The application discloses a battery cell, a battery, and an electrical device. The battery cell includes a shell, an electrode assembly and a buffering member. The shell includes two first side walls opposite to each other in a first direction, with a spacing of D1 between the two first side walls in the first direction. M electrode assemblies and N buffering members are accommodated inside the shell, where M and N are a positive integer greater than 0. In the fully charged state, the sum of the dimensions of M electrode assemblies along the first direction is D2. N buffering members and M electrode assemblies are stacked in the first direction. The buffering member is configured to be compressible, and the sum of the dimensions of N buffering members along the first direction in an uncompressed state is D3. D1, D2, and D3 meet: 0.9≤(D2+D3)/D1≤1.5.