Active materials
Active materials
Active materials in battery production are the chemical substances involved in the electrochemical reactions within the battery. The active material absorbs ions during the charging process and releases them again during the discharging process. This process of ion exchange reaction enables the storage and release of energy in the battery.
Active materials are crucial for the performance, capacity, service life and efficiency of the battery. There are two main active materials in a typical lithium-ion battery:
Cathode materials (positive electrode material)
- Lithium cobalt oxide (LiCoO₂): Commonly used in portable electronic devices.
- Lithium iron phosphate (LiFePO₄): Known for its safety and long life, often used in applications with high safety requirements.
- Lithium nickel manganese cobalt oxide (NMC, LiNiMnCoO₂): Widely used due to its good balance between energy density and safety.
- Lithium nickel cobalt aluminum oxide (NCA, LiNiCoAlO₂): Used in some high-performance applications such as electric vehicles.
Anode materials (negative electrode material)
- Graphite: Most commonly used anode material due to its good stability and availability.
- Lithium titanate (Li₄Ti₅O₁₂): Offers high safety performance and a long service life, but with a lower energy density.
- Silicon: Is increasingly used as an additive to graphite anodes to increase energy density.
Other components
In addition to the main active materials, there are other important components that contribute to the performance of the battery:
- Electrolyte: A conductive medium that transports the ions between the anode and cathode. In lithium-ion batteries, a liquid electrolyte based on lithium salts is often used.
- Separator: A microporous membrane that physically separates the anode and cathode but allows the flow of ions.
- Conductive additives and binders: Auxiliary materials that improve the electrical conductivity and mechanical stability of the electrodes.
The choice of active materials depends heavily on the intended application of the battery, as different materials have different properties such as energy density, charging speed, safety and service life.
Properties of active materials
The most important properties of active materials include:
- Specific capacity: The amount of electrical charge that can be stored per unit weight of active material, usually expressed in mAh/g.
- Cycling stability: The ability of the active material to maintain a high capacity after many charge and discharge cycles.
- Conductivity: The ability to conduct electrical charge efficiently to minimize energy loss.
The development of new active materials is an active area of research. The aims are to increase energy density, improve cycle stability, reduce manufacturing costs and increase safety. For example, work is being carried out on the development of solid-state batteries that use solid active materials and are potentially safer and more powerful than conventional batteries with liquid electrolytes.
