Cylindrical Battery Pack Layout to Prevent Cell Warpage

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Solution Overview

Problem

Existing battery packs with cylindrical batteries arranged in a lying manner suffer from poor vertical modality due to warpage of the batteries adjacent to the end face not connected to the conductive bar, leading to structural instability under vibration conditions.

Innovation Solution

The battery pack design includes cylindrical batteries arranged with their axial direction parallel to the bottom plate, featuring a spacing plate perpendicular to the bottom plate and a pressing plate on the side facing away from the bottom plate, with the pressing plate partially overlapping the spacing plate's projection pattern to constrain the batteries and prevent warpage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cylindrical batteries are arranged in a lying manner with heat exchange plates perpendicular to the bottom plate, then heat exchange efficiency is improved, but the battery pack suffers from poor vertical modality due to warpage of batteries adjacent to the end face not connected to the conductive bar

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidvertical modality
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The pressing plate acts as an intermediary component between the battery pack structure and the cylindrical batteries. It provides additional support to the end faces of batteries adjacent to the spacing plate, preventing warpage while maintaining the efficient heat exchange configuration. The pressing plate mediates the mechanical stress distribution, ensuring structural stability without compromising thermal performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the end face of the heat exchange plate is not connected to the conductive bar, then the structure is simplified, but the portion of the cylindrical battery adjacent to the end face is liable to generate warpage under vibration conditions

Engineering Contradiction:
Improvestructural complexityVSAvoidresistance to warpage
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The support function is segmented between the spacing plate (providing primary structural separation) and the pressing plate (providing localized end-face support). This segmentation allows the end face adjacent to the spacing plate to be independently supported, preventing warpage without requiring connection to the conductive bar, thus maintaining structural simplicity while improving reliability.

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If additional components are added to prevent battery warpage, then vertical modality is improved, but the number of parts and weight increase

Engineering Contradiction:
Improvevertical modalityVSAvoidnumber of parts
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The pressing plate is designed to serve multiple functions: it prevents warpage of cylindrical batteries, maintains vertical modality of the battery pack, and provides structural support during vibration conditions. By consolidating these functions into a single component, the design improves vertical modality without proportionally increasing the number of parts, as the pressing plate integrates several support and stabilization roles.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4641768A1Battery pack
Publication Date: 2025.10.29 CALB GROUP CO LTD
  • EP4641768A1 patent drawingFigure 1
  • EP4641768A1 patent drawingFigure 2
  • EP4641768A1 patent drawingFigure 3

AI summary

A battery pack includes a battery box (100), cylindrical batteries (200), a spacing plate (300) and a pressing plate (400). The battery box (100) includes a bottom plate (110). The cylindrical battery (200) is disposed in the battery box (100) and having an axial direction parallel to a first direction (X) of the bottom plate (110). A first end surface is perpendicular to a first direction (X). The spacing plate (300) has a contact surface facing towards the first end surface and perpendicular to the bottom plate. The pressing plate (400) is disposed on a side of the cylindrical battery (200) facing away from the bottom plate (110), wherein an orthogonal projection pattern of the pressing plate (400) partially overlaps with an orthogonal projection pattern of the spacing plate (300) on a reference plane parallel to the bottom plate (110).