Making Safer Battery Separators with Ceramic Coatings
This patent describes how to make a special ceramic coating for battery separators using specific lithium-containing materials and a precise drying process to improve the safety and performance of lithium-ion batteries.
Original patent title: “Ceramic-coated separators for lithium-containing electrochemical cells and methods of making the same”
This patent describes how to make a special ceramic coating for battery separators using specific lithium-containing materials and a precise drying process to improve the safety and performance of lithium-ion batteries. Granted to GM Global Technology Operations in 2021 with 21 claims and 3 forward citations, and it is expected to expire in 2039.
Coverage
What does this patent actually cover?
The patent details a method to create a ceramic-coated separator for lithium-containing electrochemical cells, like those found in electric vehicles. It involves mixing a powder of specific lithiated oxides, such as Li2SiO3 or LiAlO2, with a binder to form a slurry with a controlled viscosity (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1). This slurry is then applied onto a porous substrate, which acts as the base for the separator (Claim 1). Finally, the liquid is removed by drying the coated substrate at a temperature between 50°C and 100°C for 6 to 24 hours, forming a ceramic coating (Claim 1). This process aims to produce a separator that allows batteries to cycle at higher temperatures with reduced charge capacity loss (Claim 12). For instance, a manufacturer might use a doctor-blade coating method to apply a slurry containing LiNbO3 and carboxymethyl cellulose (CMC) onto a polymer film, then dry it in a controlled oven.
The gap
What does this patent NOT cover?
- Does not cover ceramic coatings made from non-lithiated oxides or other ceramic materials not specifically listed in ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1.
- Does not cover manufacturing processes where the slurry viscosity falls outside the 300-1400 cps range at 25°C (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover drying processes that use temperatures outside the 50-100°C range or drying times outside the 6-24 hour range (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover separators where the ceramic coating is thicker than 10 μm (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 11).
- Does not cover ceramic coatings applied to non-porous substrates (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → lies in the specific selection of lithiated oxide materials for the ceramic coating and the precisely controlled manufacturing parameters. Using these specific lithiated oxides can improve ion conductivity and overall stability, while tight controls over slurry viscosity, drying temperature, and time ensure a thin, uniform, and effective protective layer on the separator.
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
Electric vehicle battery packs (e.g., General Motors Ultium batteries)
High-performance lithium-ion batteries for power tools
Batteries for consumer electronics (laptops, smartphones)
Grid-scale energy storage systems
Why it matters
The bigger picture
Lithium-ion batteries are vital for electric vehicles and portable electronics, but safety issues like overheating and short circuits remain challenges. This patent offers a method to create a more stable ceramic coating for battery separators. Such coatings enhance thermal stability and mechanical strength, which can reduce the risk of internal short circuits and improve battery lifespan, especially under demanding conditions like high operating temperatures.
Filed
June 19, 2019
Granted
August 17, 2021
Market context
Who's building on this
Companies in this space
GM Global Technology Operations LLC, the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is actively developing electric vehicle technology, including its Ultium battery platform, which could benefit from such separator improvements. Other major battery manufacturers like LG Energy Solution, Samsung SDI, Panasonic, and CATL continuously research advanced battery separator technologies to enhance safety, energy density, and cycle life. Companies specializing in battery materials also contribute to this field.
Market impact
This type of advanced separator technology contributes to the ongoing improvements in lithium-ion battery safety and performance, which are critical for the widespread adoption of electric vehicles and more reliable portable electronics. By enabling batteries to operate more safely at higher temperatures and retain charge capacity over more cycles, it helps extend product lifespans and reduces the risk of thermal runaway events. This patent supports the development of next-generation batteries, allowing for greater energy density and faster charging without compromising safety.
Claim 1 — Plain English
What this patent covers
The patent details a method to create a ceramic-coated separator for lithium-containing electrochemical cells, like those found in electric vehicles. It involves mixing a powder of specific lithiated oxides, such as Li2SiO3 or LiAlO2, with a binder to form a slurry with a controlled viscosity (Claim 1). This slurry is then applied onto a porous substrate, which acts as the base for the separator (Claim 1). Finally, the liquid is removed by drying the coated substrate at a temperature between 50°C and 100°C for 6 to 24 hours, forming a ceramic coating (Claim 1). This process aims to produce a separator that allows batteries to cycle at higher temperatures with reduced charge capacity loss (Claim 12). For instance, a manufacturer might use a doctor-blade coating method to apply a slurry containing LiNbO3 and carboxymethyl cellulose (CMC) onto a polymer film, then dry it in a controlled oven.
The clever bit
The novelty lies in the specific selection of lithiated oxide materials for the ceramic coating and the precisely controlled manufacturing parameters. Using these specific lithiated oxides can improve ion conductivity and overall stability, while tight controls over slurry viscosity, drying temperature, and time ensure a thin, uniform, and effective protective layer on the separator.
What it does not cover
- Does not cover ceramic coatings made from non-lithiated oxides or other ceramic materials not specifically listed in Claim 1.
- Does not cover manufacturing processes where the slurry viscosity falls outside the 300-1400 cps range at 25°C (Claim 1).
- Does not cover drying processes that use temperatures outside the 50-100°C range or drying times outside the 6-24 hour range (Claim 1).
- Does not cover separators where the ceramic coating is thicker than 10 μm (Claim 11).
- Does not cover ceramic coatings applied to non-porous substrates (Claim 1).
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
12/40
Early citations
Claim breadth
14/20
Broad claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
10/20
Granted 5–10 years ago
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
$82K – $262K
Midpoint $164K · 12.8 yr remaining · 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
21 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Cai, M., Xiao, X., & Xu, J. (2021). Making Safer Battery Separators with Ceramic Coatings (U.S. Patent No. 11,094,998). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/11094998/ceramic-coated-separators-for-lithium-containing-electrochemical-cells-and-metho
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 Making Safer Battery Separators with Ceramic Coatings cover?
This patent describes how to make a special ceramic coating for battery separators using specific lithium-containing materials and a precise drying process to improve the safety and performance of lithium-ion batteries.
Who owns patent US 11094998?
GM Global Technology Operations owns this patent, granted in 2021.
When does this patent expire?
This patent is expected to expire on June 19, 2039, when the invention enters the public domain.
What is patent US 11094998 cited by?
This patent has been cited by 3 later patents that build on its ideas.
What problem does this patent solve?
Lithium-ion batteries are vital for electric vehicles and portable electronics, but safety issues like overheating and short circuits remain challenges. This patent offers a method to create a more stable ceramic coating for battery separators. Such coatings enhance thermal stability and mechanical strength, which can reduce the risk of internal short circuits and improve battery lifespan, especially under demanding conditions like high operating temperatures.
What does this patent NOT cover?
Does not cover ceramic coatings made from non-lithiated oxides or other ceramic materials not specifically listed in Claim 1.
Same assignee
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