# 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. - **Patent:** US 11094998 - **Original title:** Ceramic-coated separators for lithium-containing electrochemical cells and methods of making the same - **Owner:** GM Global Technology Operations - **Granted:** 2021 - **Status:** Active - **Times cited:** 3 - **Field:** consumer_electronics, automotive, energy, materials, telecommunications ## What it does 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. ## 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). ## 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. ## Real-world examples 1. Electric vehicle battery packs (e.g., General Motors Ultium batteries) 2. High-performance lithium-ion batteries for power tools 3. Batteries for consumer electronics (laptops, smartphones) 4. Grid-scale energy storage systems ## Why it matters 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. ## 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. **Full plain-English explainer:** https://patentbrief.org/patent/us/11094998/ceramic-coated-separators-for-lithium-containing-electrochemical-cells-and-metho **Original patent:** https://patents.google.com/patent/US11094998 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How a Hybrid Layer Stops Metal Growths in Lithium Batteries](https://patentbrief.org/patent/us/10566652/lithium-metal-battery-with-hybrid-electrolyte-system) — This patent describes a special multi-layered electrolyte system for lithium metal batteries that uses a stiff, hybrid material to block dangerous metal growths, aiming for safer, higher-energy batteries. - [Improving Lithium Battery Life with a Built-in Lithium Source](https://patentbrief.org/patent/us/10593988/electrochemical-cell-for-lithium-based-batteries) — This patent describes a method for building rechargeable lithium-based batteries with a special extra lithium source electrode inside that helps the main battery parts work better and last longer by giving them an initial charge of lithium ions. - [How a Two-Layer Coating Protects Lithium Battery Anodes](https://patentbrief.org/patent/us/11271251/battery-cell-with-anode-protective-layer) — This patent describes a lithium battery cell design that uses two special protective layers on the anode to stop harmful growths called dendrites and make the battery last longer and work better, especially in solid-state batteries. - [How to Build Solid-State Batteries with Tiny Holes for Better Electrolyte](https://patentbrief.org/patent/us/11942620/solid-state-battery-with-uniformly-distributed-electrolyte-and-methods-of-fabric) — This patent describes a method for manufacturing solid-state batteries by punching small holes through battery electrodes and then filling these holes with a liquid that hardens into a solid electrolyte, aiming for more efficient power delivery. - [Making Solid-State Battery Electrodes That Don't Swell and Crack](https://patentbrief.org/patent/us/11239459/low-expansion-composite-electrodes-for-all-solid-state-batteries) — This patent describes a special design for solid-state battery electrodes that uses tiny internal holes and spaces between particles to prevent them from expanding and cracking during charging and discharging.