Dual-Layer Cabode Electrode for Higher Capacitor Ratio Cells

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Solution Overview

Problem

Low voltage automotive battery systems, including those for electric vehicles, face challenges in delivering high power levels due to limited capacitor ratios in existing battery cells, which are typically below 2%, hindering their ability to supply sufficient cranking power and support vehicle accessory loads, especially at cold temperatures.

Innovation Solution

A dual-layered capacitive cathode electrode is fabricated using a method that involves hot-jointing a free-standing capacitive active material film and a free-standing cathode active material film, both exceeding 50 μm in thickness, and laminating them onto a current collector using conductive adhesive, with active materials like activated carbon and lithium iron phosphate, and polymer powders such as PTFE, to achieve a capacitor ratio greater than 5%.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional battery cell structures are used, then manufacturing simplicity is maintained, but capacitor ratio remains below 2% limiting power delivery

Engineering Contradiction:

Improvecapacitor ratioVSAvoidelectrode structure complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The electrode is segmented into distinct functional layers: a capacitive layer containing capacitive active material and a cathode layer containing cathode active material. This segmentation allows each layer to be optimized for its specific function, with the capacitive layer providing high power delivery capability and the cathode layer providing energy storage, thereby achieving a capacitor ratio above 2% while maintaining a manageable structural complexity through clear functional division

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The electrode employs composite material structure by combining capacitive active material (such as carbon-based materials or metal oxides) with cathode active material in a layered configuration. This composite approach enables the electrode to simultaneously exhibit capacitive characteristics for high power delivery and battery characteristics for energy storage, resolving the contradiction between increasing capacitor ratio and maintaining structural simplicity

Inventive Principle:

Principle #40Composite materials

2Power

If capacitor ratio is increased to improve power delivery, then cranking power capability is enhanced, but manufacturing process complexity increases

Engineering Contradiction:

Improvecranking powerVSAvoidmanufacturing process simplicity

Core Design Contradiction:

PowerVSEase of manufacture

Solution Approach 1:

The capacitive active material and cathode active material are prepared as separate pre-formed layers before assembly. This preliminary preparation allows each layer to be independently optimized and manufactured using standard processes, then combined in a controlled manner to achieve the desired capacitor ratio above 2%, thereby enhancing cranking power while avoiding excessive manufacturing complexity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention optimizes the thickness and composition parameters of the capacitive and cathode layers to achieve the target capacitor ratio. By carefully controlling the ratio of capacitive active material to cathode active material and adjusting layer thicknesses, the electrode delivers high cranking power capability while maintaining compatibility with existing manufacturing processes

Inventive Principle:

Principle #35Parameter changes

3Power

If dual-layered capacitive cathode electrode is implemented, then power delivery is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvepower deliveryVSAvoidlayer thickness control

Core Design Contradiction:

PowerVSManufacturing precision

Solution Approach 1:

The electrode structure implements local quality optimization by concentrating the capacitive active material in a specific layer with controlled thickness, while the cathode layer provides complementary energy storage. This localized functional assignment allows precise control over the capacitive contribution to power delivery, achieving high power capability with manageable manufacturing precision requirements through targeted material placement

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

This approach significantly increases the capacitor ratio to above 5%, enabling the delivery of higher power levels and improved performance in starting vehicles and supporting accessory loads across various temperature conditions.

Implementation Method 1

a first film including capacitive active material

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

laminating the cabode film onto opposite sides of a current collector using conductive adhesive

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS20240079544A1Battery cells with a dual-layered capacitive cabode electrode having high capacitor ratio

Publication Date: 2024.03.07 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method for fabricating a dual-layer capacitive cabode electrode includes fabricating a first film including capacitive active material; fabricating a second film including cathode active material; hot jointing the first film and the second film to create a cabode film; and laminating the cabode film onto opposite sides of a current collector using conductive adhesive.