Prismatic Battery Cell Foam Structure for Anode Expansion Pressure

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Solution Overview

Problem

High-expansion anode electrodes in prismatic battery cells cause pressure issues, leading to potential electrode film cracking, lithium dendrite growth, and deformation of the hard outer case due to large volume changes during charging and discharging cycles, which can result in reduced performance and lifespan.

Innovation Solution

Incorporating a foam structure within the battery cell to absorb and distribute the expansion of the electrode stack, maintaining a desired pressure range through compression, thereby preventing excessive pressure and ensuring mechanical stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high-expansion anode electrodes are used to increase energy density, then the energy density is improved, but the cell internal pressure increases causing electrode film cracking and lithium dendrite growth

Engineering Contradiction:

Improveenergy densityVSAvoidcell internal pressure

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a porous foam structure made of electrochemically inert material within the battery cell. This foam structure provides void space that can be occupied by electrolyte and serves as a buffer to absorb expansion forces from high-capacity anodes, thereby managing cell internal pressure while maintaining high energy density.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The foam structure acts as an intermediary element between the expanding anode electrode and the rigid cell housing. It provides a compliant interface that absorbs mechanical stress and prevents direct transmission of expansion forces to the electrode film and cell structure, eliminating the need for excessive safety margins in design.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If high-expansion anode electrodes are used to increase energy density, then the energy density is improved, but the hard outer case deforms due to large volume changes

Engineering Contradiction:

Improveenergy densityVSAvoidouter case deformation

Core Design Contradiction:

Quantity of substanceVSShape

Solution Approach 1:

The porous foam structure provides a compressible buffer that absorbs volume changes from anode expansion, preventing these changes from being transmitted to the rigid outer case, thereby maintaining case shape integrity while enabling high energy density anodes.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The foam structure is pre-installed within the cell before electrode assembly, providing beforehand cushioning against future expansion forces. This pre-positioned buffer protects the cell structure from deformation during subsequent charging cycles and anode expansion events.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Strength

If traditional battery design is used to maintain structural integrity, then mechanical stability is maintained, but the safety margins require excessive space reducing energy density

Engineering Contradiction:

Improvemechanical stabilityVSAvoidenergy density

Core Design Contradiction:

StrengthVSQuantity of substance

Solution Approach 1:

The foam structure serves as a mediator that provides mechanical compliance where needed while maintaining overall structural integrity. It allows the cell to achieve high energy density by replacing excessive rigid structural margins with a compliant foam buffer that provides equivalent protection with less space.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the mechanical parameter profile within the cell by introducing a compliant foam material with controlled compression characteristics. This allows the cell to maintain structural integrity through the foam's mechanical properties rather than through excessive rigid structural margins, thereby increasing usable space for active materials.

Inventive Principle:

Principle #35Parameter changes

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

The foam structure effectively manages the expansion of high-expansion anodes, maintaining optimal pressure within the battery cell, reducing the risk of electrode damage and deformation, and enhancing the energy density and lifespan of the prismatic battery cells.

Implementation Method 1

The foam structure is configured for reducing the cell internal pressure upon the electrode stack or the jelly roll electrodes through foam compression when the electrode stack or the jelly roll electrode expands

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

The foam structure is configured for absorbing the liquid electrolyte in a range from 0% of a volume of the foam structure to 4% of the volume of the foam structure

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentUS20240387854A1Apparatus for a high energy density prismatic battery cell with built-in foam

Publication Date: 2024.11.21 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A prismatic battery cell is provided. The prismatic battery cell includes a hard outer case including an internal volume and an electrode stack or a jelly roll electrode disposed within the internal volume. The prismatic battery cell further includes a foam structure disposed within the internal volume. The foam structure is configured for applying a desirable pressure upon the electrode stack or the jelly roll electrode and for compressing when the electrode stack or the jelly roll electrode expands.