Battery Case Groove Structure for Electrode Expansion Relief

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Solution Overview

Problem

Existing secondary batteries face issues with electrode expansion during charging and discharging, leading to pressure on the case, which can cause cracks and potential short circuits due to differences in electrode sizes and material volume changes.

Innovation Solution

Incorporating a groove region on the inner peripheral surface of the battery case to accommodate electrode expansion, with specific dimensions and orientations to reduce pressure on the electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the case is made rigid to maintain structural integrity, then strength is improved, but pressure on electrodes during expansion increases causing cracks and short circuits

Engineering Contradiction:

Improvecase strengthVSAvoidelectrode reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The inner peripheral surface of the case is segmented into multiple groove regions that can independently deform. These grooves divide the continuous surface into sections that can accommodate local electrode expansion without compromising the overall structural integrity of the case.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The case structure is modified locally by adding groove regions at specific positions where electrode expansion occurs. These grooves have different geometric properties (depth, width, orientation) tailored to match the expansion patterns of specific electrodes, allowing localized flexibility while maintaining global rigidity.

Inventive Principle:

Principle #3Local quality

2Reliability

If groove regions are added to accommodate electrode expansion, then electrode reliability is improved, but case structural complexity increases

Engineering Contradiction:

Improveelectrode reliabilityVSAvoidcase structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The groove regions create flexible zones within the case wall structure. These grooves allow the case material to deform elastically in response to electrode expansion forces, providing a simple yet effective mechanism to accommodate volume changes without adding complex moving parts or adjustment mechanisms.

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If the case is made larger to accommodate electrode expansion, then electrode reliability is improved, but battery volume increases

Engineering Contradiction:

Improveelectrode reliabilityVSAvoidbattery volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

Instead of increasing the overall battery volume to accommodate electrode expansion, the solution introduces grooves in the radial dimension (wall thickness direction) of the case. This allows the case wall itself to deform radially to accommodate electrode expansion, maintaining the external battery dimensions while providing internal flexibility.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS20260081234A1Secondary battery

Publication Date: 2026.03.19 SAMSUNG SDI CO LTD

AI summary

A secondary battery, including an electrode assembly including a first electrode, a second electrode, and a separator therebetween, a case including a bottom portion, a side wall portion connected to the bottom portion, and an opening portion facing the bottom portion, the case accommodating the electrode assembly, and a cap assembly coupled to one end of the side wall portion of the case to seal the opening portion, wherein the case includes a groove region formed on an inner peripheral surface of the side wall portion.