Boosting Fuel Cell Power for Vehicles Using Oxygen Injection
A system that boosts a vehicle's fuel cell power by injecting pure oxygen into the air supply when the engine needs extra energy.
Original patent title: “Electrochemical load management system for transportation applications”
A system that boosts a vehicle's fuel cell power by injecting pure oxygen into the air supply when the engine needs extra energy. Granted to Energy Partners Inc in 1994 with 22 claims and 90 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
This patent describes a way to make hydrogen fuel cells more powerful for vehicles by dynamically changing the air they breathe. Under normal driving, the fuel cell uses regular air as an oxidant. When the vehicle demands high power, such as during acceleration, the system detects the increased amperage and automatically opens a valve to inject pure oxygen into the air intake. This enriches the oxygen content to between 30% and 60%, allowing the fuel cell to generate more power without needing a massive, heavy fuel cell stack.
The gap
What does this patent NOT cover?
- Does not cover fuel cell systems that operate at temperatures above the boiling point of water.
- Does not cover systems that enrich oxygen to levels higher than 60% by volume.
- Does not cover fuel cells that operate at pressures significantly higher than 30 psig above atmospheric pressure.
- Does not cover systems that lack a mechanism to sense amperage output to trigger oxygen injection.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
Instead of building a fuel cell large enough to handle peak power loads constantly, the inventors used a 'peak-shaving' approach by temporarily modifying the chemical reactant mixture only when the load spiked.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Experimental hydrogen fuel cell prototype vehicles from the 1990s
High-performance hydrogen fuel cell power modules
Stationary fuel cell systems with peak-load management
Why it matters
The bigger picture
This patent addressed a fundamental limitation of early fuel cell vehicles: the trade-off between size and peak power. By using oxygen enrichment, engineers could design smaller, lighter fuel cells for cruising while still having the 'boost' needed for highway driving or climbing hills. It represents a 1990s-era approach to optimizing hydrogen power systems for the constraints of automotive packaging.
Filed
August 13, 1992
Granted
September 13, 1994
Market context
Who's building on this
Companies in this space
The core concepts of fuel cell load management are now standard in the R&D labs of major automotive manufacturers like Toyota, Hyundai, and Honda. These companies focus on optimizing air management systems to improve the power density of their commercial fuel cell stacks.
Market impact
This patent contributed to the body of knowledge regarding hydrogen fuel cell optimization during a period of intense interest in zero-emission vehicle alternatives. It helped define the technical parameters for managing oxidant supply, influencing how engineers think about power density and auxiliary system integration in fuel cell electric vehicles.
Claim 1 — Plain English
What this patent covers
This patent describes a way to make hydrogen fuel cells more powerful for vehicles by dynamically changing the air they breathe. Under normal driving, the fuel cell uses regular air as an oxidant. When the vehicle demands high power, such as during acceleration, the system detects the increased amperage and automatically opens a valve to inject pure oxygen into the air intake. This enriches the oxygen content to between 30% and 60%, allowing the fuel cell to generate more power without needing a massive, heavy fuel cell stack.
The clever bit
Instead of building a fuel cell large enough to handle peak power loads constantly, the inventors used a 'peak-shaving' approach by temporarily modifying the chemical reactant mixture only when the load spiked.
What it does not cover
- Does not cover fuel cell systems that operate at temperatures above the boiling point of water.
- Does not cover systems that enrich oxygen to levels higher than 60% by volume.
- Does not cover fuel cells that operate at pressures significantly higher than 30 psig above atmospheric pressure.
- Does not cover systems that lack a mechanism to sense amperage output to trigger oxygen injection.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Moderate
Citation count
39/40
Highly cited
Claim breadth
15/20
Broad claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$41K – $131K
Midpoint $82K · expired or expiring · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
22 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Ewan, J. M., Misiasxek, S. M., & Jr., D. P. A. (1994). Boosting Fuel Cell Power for Vehicles Using Oxygen Injection (U.S. Patent No. 5,346,778). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/5346778/electrochemical-load-management-system-for-transportation-applications
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does Boosting Fuel Cell Power for Vehicles Using Oxygen Injection cover?
A system that boosts a vehicle's fuel cell power by injecting pure oxygen into the air supply when the engine needs extra energy.
Who owns patent US 5346778?
Energy Partners Inc owns this patent, granted in 1994.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 5346778 cited by?
This patent has been cited by 90 later patents that build on its ideas.
What problem does this patent solve?
This patent addressed a fundamental limitation of early fuel cell vehicles: the trade-off between size and peak power. By using oxygen enrichment, engineers could design smaller, lighter fuel cells for cruising while still having the 'boost' needed for highway driving or climbing hills. It represents a 1990s-era approach to optimizing hydrogen power systems for the constraints of automotive packaging.
What does this patent NOT cover?
Does not cover fuel cell systems that operate at temperatures above the boiling point of water.
Patent monitoring