# 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. - **Patent:** US 4302518 - **Original title:** Electrochemical cell with new fast ion conductors - **Owner:** Individual - **Granted:** 1981 - **Status:** Public domain (expired) - **Times cited:** 90 - **Field:** consumer_electronics, energy, materials, automotive ## What it does 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. ## 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. ## 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. ## Real-world examples 1. Smartphone batteries (iPhone, Android) 2. Laptop battery packs 3. Electric vehicle battery cells (Tesla, etc.) 4. Portable power tools ## Why it matters 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. ## 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. **Full plain-English explainer:** https://patentbrief.org/patent/us/4302518/lithium-ion-battery-cathode **Original patent:** https://patents.google.com/patent/US4302518 --- _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 Lithium-Ion Battery Cathodes Are Made](https://patentbrief.org/patent/us/4357215/lithium-ion-cathode-goodenough) — A foundational 1982 method for creating the materials used in rechargeable lithium-ion batteries by removing ions at low temperatures. - [Early Lithium-Ion Battery Design Using Chalcogenides](https://patentbrief.org/patent/us/4009052/rechargeable-lithium-battery) — This 1977 patent describes an early rechargeable battery design using lithium as one electrode and titanium disulfide as the other, a key step towards modern lithium-ion technology. - [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 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. - [How to Fast-Charge Lithium Batteries Without Damaging Them](https://patentbrief.org/patent/us/10700376/methods-for-fast-charging-and-detecting-lithium-plating-in-lithium-ion-batteries) — This patent describes a three-phase method for quickly charging lithium-ion batteries while carefully controlling voltages to prevent harmful lithium metal buildup and electrolyte damage.