Non-Rectangular Bare Cell Stacks for Curved Enclosures

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Solution Overview

Problem

Conventional battery pack designs for portable electronic devices are inefficient in utilizing space due to the requirement for rectangular cells of the same size and dimensions, which limits packaging efficiency and capacity, especially in devices with curved or irregularly shaped enclosures.

Innovation Solution

The design involves forming a cell compartment within the device enclosure to accommodate non-rectangular or irregularly shaped bare cell stacks, using a sealing mechanism such as a flexible sheet with aluminum and polypropylene layers to enclose the cells, and incorporating an electrolyte-resistant layer for protection, allowing for efficient use of space and alignment simplification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If rectangular battery cells are used in conventional battery pack designs, then manufacturing and assembly are simplified, but packaging efficiency and space utilization deteriorate in devices with curved or irregularly shaped enclosures

Engineering Contradiction:

Improvemanufacturing and assembly simplicityVSAvoidpackaging efficiency

Core Design Contradiction:

Ease of manufactureVSVolume of moving object

Solution Approach 1:

The patent applies asymmetry by transitioning from conventional rectangular battery cells to non-rectangular cell stacks that conform to the irregular or curved shapes of device enclosures. The cell stacks are designed with custom geometries (e.g., curved surfaces, varying thicknesses) that match the specific contours of the device interior, thereby maximizing space utilization while maintaining manufacturability through standardized production processes for the asymmetric forms.

Inventive Principle:

Principle #4Asymmetry

2Volume of moving object

If non-rectangular cell stacks are used to fit curved enclosures, then packaging efficiency increases, but alignment precision and assembly complexity increase

Engineering Contradiction:

Improvepackaging efficiencyVSAvoidalignment precision

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-forming the cell stacks with the exact non-rectangular geometry required to match the device enclosure contours before assembly. The cell stacks are manufactured in advance with precise shaping that eliminates the need for complex alignment operations during final assembly, as the pre-formed geometry inherently conforms to the enclosure shape.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by varying the dimensions and shape of different regions of the cell stack to match the local contours of the device enclosure. Different portions of the cell stack have different geometries (e.g., curved edges, varying thickness) that are optimized for their specific locations within the irregular enclosure, thereby achieving high packaging efficiency without requiring uniform precision across the entire assembly process.

Inventive Principle:

Principle #3Local quality

3Volume of moving object

If flexible pouches are used to enclose rolled electrodes, then packaging efficiency reaches 90-95%, but the battery pack cannot utilize free space outside rectangular boundaries

Engineering Contradiction:

Improvecell packaging efficiencyVSAvoidform factor adaptability

Core Design Contradiction:

Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by dividing the battery into multiple discrete cell stacks, each with its own flexible pouch enclosure. This segmentation allows each individual cell stack to be independently shaped and sized to fit specific regions within the device, while collectively they can conform to the overall irregular or curved device enclosure, thereby combining high packaging efficiency with form factor adaptability.

Inventive Principle:

Principle #1Segmentation

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 approach enables the use of non-rectangular cell stacks to fit within curved enclosures, increasing packaging efficiency and capacity while reducing the risk of damage during assembly and installation by eliminating the need for precise alignment.

Implementation Method 1

a sealing mechanism bonded to the cell compartment to enclose the bare cell stack and electrolyte within the cell compartment

Methodology Applied

Scientific EffectBonding: Adhesive

Implementation Method 2

The flexible sheet includes a layer of aluminum and a layer of polypropylene... the battery enclosure includes an electrolyte resistant layer

Methodology Applied

Scientific EffectElectrolyte resistance:

Data Source

PatentUS10749155B2Packaging of bare cell stacks within device enclosures for portable electronic devices

Publication Date: 2020.08.18 APPLE INC

AI summary

A battery cell compartment is formed with the device enclosure of an electronic device. Bare cell stacks are placed within the cell compartment. The resulting battery powers the electronic device.