Several key components of Lithium-ion batteries
1. **Cathode (Positive Electrode):**
The cathode is typically made by applying lithium-containing compounds onto a metal aluminum foil. Common active materials include lithium manganate, lithium cobaltate, ternary materials (such as lithium nickel manganese cobalt oxide), and lithium iron phosphate. The primary function of the cathode material is to store and release lithium ions.
2. **Anode (Negative Electrode):**
The anode is usually made from carbon materials or non-carbon materials applied onto a metal copper foil. The anode material is the main body for lithium storage in the battery, allowing lithium ions to intercalate and de-intercalate during charging and discharging. The anode active material also includes binders and additives, which are mixed to form a paste adhesive that is evenly applied to both sides of the copper foil, then dried and rolled.
3. **Separator:**
The separator is a special composite membrane that primarily functions to prevent direct contact between the positive and negative electrodes, avoiding short circuits. Common separator materials include polyolefin membranes (such as polypropylene, and polyethylene) and ceramic membranes. The performance of the separator affects the safety and performance of the battery.
4. **Electrolyte:**
The main function of the electrolyte is to provide a medium for the transport of lithium ions. Common electrolytes include organic electrolytes and solid-state electrolytes. Organic electrolytes have high ionic conductivity and good lithium ion transport performance but pose safety risks such as combustion and volatility; solid-state electrolytes, on the other hand, offer better safety performance but have lower ionic conductivity.
5. **Housing:**
The housing is used for battery encapsulation and protection of the internal structure. It comes in various types such as steel casing, aluminum casing, nickel-plated iron casing (used for cylindrical batteries), and aluminum-laminated film (used for soft packaging). The battery cap is also part of the housing and serves as the terminal for the positive and negative electrodes of the battery.
Additionally, lithium-ion batteries may also include components such as the positive electrode current collector (aluminum foil) and the negative electrode current collector (copper foil). In summary, these parts work together to enable lithium-ion batteries to operate efficiently and safely.
