Stacked Wedge Electrodes on Composite Rotor for High-G EMB

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Solution Overview

Problem

Electrodes in electromechanical battery (EMB) flywheel energy storage modules face high centrifugal forces, especially in small rotors, which require a substantial increase in electrode area to enhance power output while avoiding electrical conductivity issues from carbon-fiber composites.

Innovation Solution

A stacked wedge-like electrode array is mounted on the inner surface of a fiber-composite rotor, using non-conductive glass or basalt fibers to manage high-g forces and increase electrode area, with a design that includes vertically spaced cells and tapered metal electrodes sheathed in high dielectric polymers to enhance capacitance and voltage-holding ability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If electrodes are mounted on the inner surface of a carbon-fiber rotor, then the rotor structure is simplified and strength is improved, but electrical conductivity interferes with proper operation of the E-S generator/motor electrodes

Engineering Contradiction:

Improverotor strengthVSAvoidelectrode operation reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The rotor is segmented into two distinct parts: an inner non-conductive core (made of E-glass or S-glass fiber composite) and an outer carbon-fiber composite shell. This segmentation allows the inner core to provide the mounting surface for electrodes while the outer shell provides structural strength, resolving the conflict between structural integrity and electrical non-conductivity requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner non-conductive fiber-composite core acts as an intermediary layer between the electrode mounting requirement and the carbon-fiber rotor structure. This intermediate layer provides the necessary electrical isolation while allowing the carbon-fiber outer shell to maintain rotor strength and structural performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Volume of moving object

If rotor size is reduced to achieve compact design, then space requirements are reduced, but centrifugal forces increase to over a million g at operating speeds

Engineering Contradiction:

Improverotor volumeVSAvoidcentrifugal force

Core Design Contradiction:

Volume of moving objectVSForce

Solution Approach 1:

The rotor employs composite materials (E-glass or S-glass fiber composite for the inner core, carbon fiber composite for the outer shell) that provide high strength-to-weight ratios. This allows the rotor to withstand extreme centrifugal forces of over a million g while maintaining a compact size suitable for vehicular applications.

Inventive Principle:

Principle #40Composite materials

3Power

If electrode area is increased to enhance power output, then power generation capability is improved, but the equivalent weight under centrifugal force increases to 10-100 metric tons

Engineering Contradiction:

Improvepower outputVSAvoidcentrifugal force on electrodes

Core Design Contradiction:

PowerVSForce

Solution Approach 1:

The electrode array extends in multiple dimensions within the available space on the inner surface of the rotor. By utilizing the full three-dimensional space and creating a stacked wedge-like array configuration, the electrode area is substantially increased without proportionally increasing the centrifugal load, as the electrodes are distributed throughout the available volume rather than concentrated in a single plane.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 solution effectively doubles or triples the electrode area, sustaining high centrifugal forces and improving power output, while maintaining electrical non-conductivity within the rotor, suitable for vehicular and stationary applications.

Implementation Method 1

tapered metal electrodes sheathed in high dielectric polymers to enhance capacitance and voltage-holding ability

Methodology Applied

Scientific EffectDielectric: Dielectric

Implementation Method 2

the centrifugal force at the inner surface of the rotor may be of in excess of a million g

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

fiber-composite rotor

Methodology Applied

Scientific EffectComposite materials: Composite Materials

Data Source

PatentUS10693343B2Electrostatic generator/motor electrodes located on the inner surface of an electromechanical battery rotor

Publication Date: 2020.06.23 LAWRENCE LIVERMORE NAT SECURITY LLC

AI summary

A geometric design of E-S generator motor electrodes mounted on the inner surface of a fiber-composite rotor is provided. The electrode configuration is able to sustain very high g levels. The rotor may be funned of carbon-fiber wound on top of an inner E car S-glass fiber composite core. The electrode design provides the needed area to satisfy the power requirements of the storage system and utilizes a stacked wedge-like electrode array that both solves the high-g problem and results in a doubling or tripling of the electrode area, relative to that of electrodes that conform to the inner cylindrical surface of the rotor.