Battery Pack Side Plate Thickness Variation for Pressure Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery packs face issues with uneven pressure distribution on rolled electrode bodies, leading to increased electrolyte distribution unevenness and decreased battery performance due to the deformation of wide side plates under comb spacer pressure.
Innovation Solution
A battery pack design featuring a wide side plate with a thick portion that remains non-deformable under comb spacer pressure and a thin portion that deforms to ensure even pressure distribution on the power generating portion of the electrode body, maintaining flatness and preventing bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the wide side plate is made thin to reduce overall cell thickness, then the battery pack becomes more compact, but the wide side plate deforms under comb spacer pressure causing uneven pressure distribution on the electrode body
Solution Approach 1:
The wide side plate is designed with non-uniform thickness: a thin portion (first thickness) at the edges and a thick portion (second thickness greater than the first) at the center region. This local quality variation allows the plate to be thin overall for compactness while having a thick center region that resists deformation under comb spacer pressure, ensuring uniform pressure distribution on the electrode body's power generating portion.
2Manufacturing precision
If the wide side plate is made thick to prevent deformation under comb spacer pressure, then pressure distribution uniformity is improved, but the overall cell thickness and battery pack size increase
Solution Approach 1:
Instead of making the entire wide side plate thick, the invention applies thickness variation locally: the center region has increased thickness to prevent deformation and ensure uniform pressure distribution, while the edge regions remain thin to minimize overall cell thickness. This resolves the contradiction by concentrating the thick portion only where structurally necessary.
3Volume of moving object
If the entire wide side plate is made uniformly thin, then the battery pack becomes more compact, but the pressure distribution on the electrode body becomes uneven leading to increased electrolyte distribution unevenness
Solution Approach 1:
The wide side plate features a thick portion at the center (where it contacts the electrode body's power generating portion) and thin portions at the edges. This local thickness variation ensures that the center region maintains uniform pressure distribution on the electrode body, preventing electrolyte distribution unevenness, while the overall compact size is preserved through the thin edge regions.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A battery pack (2) includes a plurality of non-aqueous electrolyte single cells (10), each single cell being such that a rolled electrode body (16) is housed in a flat case (11); a plurality of spacers (20); and a banding member (5, 7). The rolled electrode body includes a collector portion (17, 18), and a power generating portion (16a). Each spacer (20) has at least one recessed portion provided on at least one surface that faces the adjacent single cell (10). A side plate (31) of the case that faces the surface of the spacer on which the recessed portion is provided includes a thick portion (31a) that contacts the power generating portion (16a) of the rolled electrode body (16) inside the case, and a thin portion (31b) that is thinner than the thick portion (31a) and is continuous with both sides of the thick portion (31a) in the rolling axis direction. The surface of the spacer (20) on which the recessed portion is provided abuts against the thick portion only.