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.

What it 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.

What it doesn't 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.

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.

Real-world examples

• 1.Smartphone batteries (iPhone, Android)
• 2.Laptop battery packs
• 3.Electric vehicle battery cells (Tesla, etc.)
• 4.Portable power tools