Approximately 70% of all cobalt produced globally is used in rechargeable lithium-ion batteries. Cobalt stabilizes the cathode structure and enables higher energy density, longer cycle life, and improved thermal stability. It is a key component in NMC (Nickel-Manganese-Cobalt) and NCA (Nickel-Cobalt-Aluminum) cathode chemistries powering electric vehicles, smartphones, laptops, power tools, and grid-scale energy storage systems. As demand for EVs and consumer electronics grows, cobalt remains strategically important despite ongoing efforts to reduce its content in next-generation battery technologies.

Cobalt-based superalloys (such as Stellite, Haynes 188, and Mar-M509) retain exceptional mechanical strength, wear resistance, and corrosion resistance at temperatures exceeding 1000°C. These alloys are critical components in jet engine turbine blades, combustion chambers, vanes, and rocket propulsion systems. The aerospace industry relies on cobalt superalloys for parts that must withstand the most extreme conditions encountered in modern aviation and space exploration. Cobalt is also alloyed with chromium and tungsten to produce hardfacing materials used in industrial machinery and cutting tools.

Cobalt's ferromagnetic properties make it essential for high-performance permanent magnets, including Alnico (aluminum-nickel-cobalt) and SmCo (samarium-cobalt) magnets used in electric motors, generators, sensors, and aerospace applications. In industrial chemistry, cobalt catalysts are used in the Fischer-Tropsch process to convert natural gas into synthetic fuels, in petroleum refining for hydrodesulfurization, and in the production of polyester precursors. Cobalt is also a critical binder in tungsten carbide hard metals used for cutting, drilling, and mining tools.

Cobalt compounds have been used for over 2,500 years to produce vivid blue pigments in glass, ceramics, paints, and inks — known as cobalt blue, cerulean, and smalt. In modern medicine, cobalt-60 (a radioactive isotope) is used in radiotherapy to treat cancer and in industrial radiography for non-destructive testing of welds and materials. Cobalt-chromium alloys are extensively used in orthopedic implants such as hip and knee replacements, dental prosthetics, and cardiovascular stents due to their excellent biocompatibility, wear resistance, and mechanical strength.