How Lithium-Cobalt Battery Cathodes Were Invented
This 1981 patent details the chemistry behind the lithium-cobalt oxide cathodes that power almost every modern smartphone, laptop, and electric vehicle.
Original patent title: “Electrochemical cell with new fast ion conductors”
This 1981 patent details the chemistry behind the lithium-cobalt oxide cathodes that power almost every modern smartphone, laptop, and electric vehicle. Granted to Individual in 1981 with 9 claims and 90 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
The patent describes a method for creating a specific type of battery electrode material using a layered atomic structure known as alpha-NaCrO2. By using electrochemical extraction, the inventors removed lithium ions from the material at low temperatures, which was previously impossible using high-heat manufacturing methods. This creates a stable, rechargeable structure where lithium ions can move in and out of the cathode, allowing the battery to store and release energy efficiently. It specifically identifies lithium-cobalt and lithium-nickel oxides as the active materials for these cathodes.
The gap
What does this patent NOT cover?
- Does not cover battery designs using liquid electrolytes exclusively.
- Does not cover non-layered crystal structures or different chemical formulas outside of AxMyO2.
- Does not cover the manufacturing of the anode component itself, only its use in conjunction with the claimed cathode.
- Does not cover high-temperature synthesis methods for these materials.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The inventors realized that by extracting lithium ions electrochemically at low temperatures, they could bypass the thermodynamic instability that caused these materials to fall apart when synthesized at high temperatures.
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
Smartphone batteries (iPhone, Android)
Laptop battery packs
Electric vehicle battery cells (Tesla, etc.)
Portable power tools
Why it matters
The bigger picture
This patent is the foundation of the modern lithium-ion battery industry. By enabling a stable, high-energy-density cathode, it allowed for the transition from bulky, disposable batteries to the compact, rechargeable power sources that enabled the mobile computing revolution. John B. Goodenough later received the Nobel Prize in Chemistry for this work.
Filed
March 31, 1980
Granted
November 24, 1981
Market context
Who's building on this
Companies in this space
Every major battery manufacturer, including Panasonic, LG Energy Solution, CATL, and Samsung SDI, builds upon the fundamental chemistry established here. While the original patent has long since expired, the basic chemistry of lithium-cobalt-oxide (LCO) remains a standard in the industry.
Market impact
This patent effectively launched the portable electronics industry by providing the first viable high-energy-density cathode. It shifted the global energy storage market away from nickel-cadmium and lead-acid batteries toward the lithium-ion standard that dominates the global economy today.
Claim 1 — Plain English
What this patent covers
The patent describes a method for creating a specific type of battery electrode material using a layered atomic structure known as alpha-NaCrO2. By using electrochemical extraction, the inventors removed lithium ions from the material at low temperatures, which was previously impossible using high-heat manufacturing methods. This creates a stable, rechargeable structure where lithium ions can move in and out of the cathode, allowing the battery to store and release energy efficiently. It specifically identifies lithium-cobalt and lithium-nickel oxides as the active materials for these cathodes.
The clever bit
The inventors realized that by extracting lithium ions electrochemically at low temperatures, they could bypass the thermodynamic instability that caused these materials to fall apart when synthesized at high temperatures.
What it does not cover
- Does not cover battery designs using liquid electrolytes exclusively.
- Does not cover non-layered crystal structures or different chemical formulas outside of AxMyO2.
- Does not cover the manufacturing of the anode component itself, only its use in conjunction with the claimed cathode.
- Does not cover high-temperature synthesis methods for these materials.
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
6/20
Moderate scope
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
$32K – $101K
Midpoint $63K · 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.
Patent Claims
0 independent claims · 1 dependent
Claims are the legal boundaries of the patent. An independent claim stands alone. A dependent claim adds limitations to its parent, narrowing — but not broadening — the scope.
The original legal language
Original claims
9 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Mizuchima, K., & Goodenough, J. B. (1981). How Lithium-Cobalt Battery Cathodes Were Invented (U.S. Patent No. 4,302,518). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/4302518/lithium-ion-battery-cathode
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 How Lithium-Cobalt Battery Cathodes Were Invented cover?
This 1981 patent details the chemistry behind the lithium-cobalt oxide cathodes that power almost every modern smartphone, laptop, and electric vehicle.
Who owns patent US 4302518?
Individual owns this patent, granted in 1981.
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 4302518 cited by?
This patent has been cited by 90 later patents that build on its ideas.
What problem does this patent solve?
This patent is the foundation of the modern lithium-ion battery industry. By enabling a stable, high-energy-density cathode, it allowed for the transition from bulky, disposable batteries to the compact, rechargeable power sources that enabled the mobile computing revolution. John B. Goodenough later received the Nobel Prize in Chemistry for this work.
What does this patent NOT cover?
Does not cover battery designs using liquid electrolytes exclusively.
Same assignee
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