Recessed Battery Case Structure for Cooling and Compact Cell Stacking

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Solution Overview

Problem

Existing secondary batteries face challenges in achieving efficient cooling and compact design while maintaining high energy density.

Innovation Solution

The design incorporates a case with a recessed portion and non-recessed portions on the bottom surface, accommodating an electrode assembly with varying active material coating amounts and shapes to fit the case's geometry, and includes a cooling channel between stacked cells for enhanced heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a flat bottom surface is used in the case, then the manufacturing process is simple, but the cooling efficiency is insufficient

Engineering Contradiction:
Improvecase manufacturing simplicityVSAvoidcooling efficiency
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The bottom surface of the case is designed with asymmetric geometry, featuring a recessed portion and a non-recessed portion. This asymmetric structure enables differentiated cooling strategies: the recessed portion provides direct thermal contact with the electrode assembly for efficient heat dissipation, while the non-recessed portion maintains structural integrity and simplifies manufacturing processes.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Different regions of the bottom surface are assigned different functional qualities. The recessed portion is optimized for thermal management with enhanced cooling capability, while the non-recessed portion maintains structural support functions. This local differentiation allows the case to simultaneously achieve improved cooling efficiency and manufacturing simplicity in different areas.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If the electrode assembly is designed to fit the recessed portion, then the energy density is increased, but the manufacturing precision requirement increases

Engineering Contradiction:
Improveenergy densityVSAvoidelectrode assembly fitting precision
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The electrode assembly is segmented into two distinct parts: a first electrode assembly that fits into the recessed portion and a second electrode assembly that fits into the non-recessed portion. This segmentation allows each electrode assembly to be optimized independently for its specific location, maximizing energy density in the recessed area while maintaining easier manufacturing tolerances in the non-recessed area.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If cells are stacked vertically without recessed portions, then the structure is simple, but the vertical stacking height is large

Engineering Contradiction:
Improvestacking structure simplicityVSAvoidvertical stacking height
Core Design Contradiction:
Device complexityVSLength of stationary object

Solution Approach 1:

The first electrode assembly is nested within the recessed portion of the case, allowing it to be positioned closer to the electrode assembly above it in the stacked configuration. This nesting arrangement enables the cells to be stacked vertically with reduced overall height, as the recessed portions create interlocking interfaces that eliminate gaps between stacked cells.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 configuration improves cooling efficiency and allows for a more compact battery module with increased energy density and reduced vertical stacking height.

Implementation Method 1

a cooling channel between the upper rack cells and the lower rack cells

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a cooling channel between the upper rack cells and the lower rack cells

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4683020A1Secondary battery having case with recessed portion and manufacturing method thereof
Publication Date: 2026.01.21 SAMSUNG SDI CO LTD
  • EP4683020A1 patent drawingFigure 1
  • EP4683020A1 patent drawingFigure 2
  • EP4683020A1 patent drawingFigure 3

AI summary

A secondary battery including a case having a bottom surface, the bottom surface including a recessed portion and a non-recessed portion, the recessed portion being recessed into an interior of the case, and the non-recessed portion being flat, and an upper surface facing the bottom surfaces, the upper surfaces including a cap assembly, and an electrode assembly accommodated in the case.