Expanding Battery Mandrel for Uniform Solid-State Cell Compression

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Solution Overview

Problem

Current solid state battery designs lack effective methods for generating high compression in cylindrical formats, leading to nonuniform compression and degradation over time, which affects ion contact and overall battery performance.

Innovation Solution

An expanding mandrel system with a cylindrical design and slits, allowing for mechanical expansion through a screw or shim insertion, ensuring uniform compression of electrodes and maintaining contact throughout the battery's life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If external compression is applied to solid state battery electrodes, then compression is generated to ensure contact, but the compression becomes nonuniform and declines over time

Engineering Contradiction:

Improvecompression forceVSAvoidcompression stability

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

Instead of applying external compression to achieve electrode contact, the patent inverts the approach by using an expanding mandrel that pushes electrodes outward from the center, creating uniform compression force from the inside out. This eliminates the nonuniform compression and degradation issues associated with external compression methods.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces an expanding mandrel as an intermediary component between the electrodes and the cell structure. This mandrel serves as a mediator that distributes compression force uniformly across all electrodes, preventing the nonuniform compression and contact loss that occurs with direct external compression.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Force

If external compression devices like tie rods are used, then compression is generated, but considerable mass is added to the battery structure

Engineering Contradiction:

Improvecompression forceVSAvoidbattery mass

Core Design Contradiction:

ForceVSWeight of moving object

Solution Approach 1:

The patent extracts and eliminates the need for external compression devices like tie rods by implementing an internal expanding mandrel system. This removes the considerable mass associated with external compression structures while maintaining the necessary compression force for electrode contact.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using external structures to apply compression, the patent inverts the approach by using an internal expanding mandrel that generates compression force from within the cell, eliminating the need for heavy external compression devices.

Inventive Principle:

Principle #13The other way round (Inversion)

3Force

If planar compression of flat cell stacks is used, then compression is generated, but the compression is nonuniform over the cell stack

Engineering Contradiction:

Improvecompression forceVSAvoidcompression uniformity

Core Design Contradiction:

ForceVSManufacturing precision

Solution Approach 1:

The patent inverts the compression approach by expanding the mandrel from the inside out, which naturally distributes compression force uniformly across the entire cell stack. This eliminates the nonuniform compression issues inherent in planar external compression methods.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The expanding mandrel applies compression force locally at each point of electrode contact, ensuring uniform compression throughout the entire cell stack. Each region receives appropriate compression force independently, achieving manufacturing precision and uniformity.

Inventive Principle:

Principle #3Local quality

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 expanding mandrel provides consistent and adjustable compression, enhancing ion conductivity, preventing voids, and extending battery life by dynamically altering internal pressure, thus improving safety and performance.

Implementation Method 1

an expander screwed inside of or inserted within the cylindrical mandrel, forcing the cylindrical mandrel to uniformly expand in a radial direction

Methodology Applied

Scientific EffectMechanical expansion: Mechanical Force

Implementation Method 2

forcing the plurality of electrolytes to compress against each other and to press against an inner wall of the cylindrical cell

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentUS20230395782A1Expanding battery mandrel

Publication Date: 2023.12.07 AEROSPACE CORP

AI summary

An expanding battery mandrel includes a cylindrical cell, a cylindrical mandrel having a slit along a length of the cylindrical mandrel, and a plurality of electrolytes wrapped around the cylindrical cell. The expanding battery mandrel also includes an expander screwed inside of or inserted within the cylindrical mandrel, forcing the cylindrical mandrel to uniformly expand in a radial direction and forcing the plurality of electrolytes to compress against each other and to press against an inner wall of the cylindrical cell.