Bent End Plate Structure for Battery Module Swelling Control

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Solution Overview

Problem

Conventional methods for preventing swelling phenomena in battery modules, such as using soft elastic buffers or high rigidity end plates, face challenges like increased manufacturing costs, weight, and difficulty in controlling cell assembly thickness, while also being inefficient in absorbing swelling pressure.

Innovation Solution

A battery module design featuring an end plate with a support part, an outer side part bent upward, and an inner side part bent inward, which are integrally formed and include a guide groove to limit movement, supporting the cell assembly and preventing shape changes due to swelling by absorbing pressure through elasticity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a high rigidity end plate is installed around battery cells to control swelling phenomena, then swelling control is improved, but manufacturing costs increase and volume and weight of the battery module increase

Engineering Contradiction:
Improveswelling controlVSAvoidweight of battery module
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The end plate is segmented into multiple functional regions: a support plate providing baseline support, pressing parts extending from the support plate to apply localized pressing force on battery cells, and elastic elements connecting the pressing parts to enable dynamic pressure adjustment. This segmentation allows the end plate to achieve effective swelling control with reduced overall rigidity requirements, thereby reducing weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The end plate incorporates elastic elements (such as elastic rods or springs) that allow the pressing parts to dynamically adjust their position and applied force in response to battery cell swelling. This dynamic capability enables the end plate to maintain effective swelling control without requiring excessive static rigidity, thus reducing the weight of the end plate and overall battery module.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a pressing type end plate is used to prevent swelling phenomena, then swelling control is improved, but the volume and weight of the battery module increase

Engineering Contradiction:
Improveswelling controlVSAvoidvolume of battery module
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The end plate utilizes elastic elements and flexible pressing parts that can deform and adapt to the swelling of battery cells. This flexibility allows the end plate to maintain effective contact and pressing force on the cells without requiring a large volume, thereby controlling swelling while minimizing the volume occupied by the end plate itself and the overall battery module.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If a high rigidity end plate is installed around battery cells to control swelling phenomena, then swelling control is improved, but manufacturing costs increase

Engineering Contradiction:
Improveswelling controlVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The end plate is divided into a support plate and multiple independent pressing parts connected by elastic elements. This segmentation allows for simplified manufacturing processes, as each component can be manufactured separately using standard techniques and then assembled. The support plate can be a simple rigid structure, while the pressing parts and elastic elements can be produced through conventional machining or molding, significantly reducing manufacturing costs compared to a single monolithic high-rigidity end plate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dynamic design with elastic elements allows the end plate to achieve effective swelling control without requiring expensive high-rigidity materials throughout the entire structure. Only the support plate needs to be rigid, while the pressing parts can use lighter, less expensive materials combined with elastic elements, thereby reducing material costs and overall manufacturing expenses.

Inventive Principle:
Principle #15Dynamics

4Reliability

If swelling phenomena is prevented by the pressing type end plate alone, then swelling control is improved, but it is difficult to control a thickness allowance of the unit battery cell when constructing a cell assembly

Engineering Contradiction:
Improveswelling controlVSAvoidthickness allowance control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The end plate acts as an intermediary component between the battery cells and the external environment. By providing a standardized support plate with defined geometry and positioning features, it establishes a reference framework that facilitates precise thickness control during cell assembly construction. The support plate's rigid structure provides stable reference surfaces for measuring and controlling the thickness allowance of battery cells, thereby improving manufacturing precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively prevents shape changes in battery modules caused by swelling, reduces the module's volume and weight, and lowers manufacturing costs by forming the end plate through bending a sheet, thereby enhancing energy density and product reliability.

Implementation Method 1

an end plate having a support part to support a bottom of the cell assembly, an outer side part bent in upward direction from each of one end and the other end of the support part, and an inner side part bent down in inward direction from a top of the outer side part

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3576180B1End plate, battery module, battery pack comprising the battery module and vehicle comprising the battery pack
Publication Date: 2023.10.25 LG ENERGY SOLUTION LTD
  • EP3576180B1 patent drawingFigure 1
  • EP3576180B1 patent drawingFigure 2
  • EP3576180B1 patent drawingFigure 3

AI summary

A battery module according to an embodiment of the present disclosure includes a cell assembly including a plurality of battery cells stacked side by side in horizontal direction, each battery cell standing erect in up-down direction, and an end plate having a support part to support a bottom of the cell assembly, an outer side part bent in upward direction from each of one end and the other end of the support part, and an inner side part bent down in inward direction from a top of the outer side part.