The raw materials of lithium batteries primarily include positive electrode materials, negative electrode materials, electrolyte, and separators. The selection and proportion of these materials directly impact the performance and safety of lithium batteries.
1. Cathode Materials: The positive electrode material is one of the most important components of a lithium battery, determining the battery's energy density and voltage platform. Common cathode materials currently on the market include lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium iron phosphate (LFP), and ternary materials (such as lithium nickel cobalt manganese oxide (NCM) and lithium nickel cobalt aluminum oxide (NCA).
Each of these materials has its own unique characteristics. For example, lithium cobalt oxide offers high specific capacity and high operating voltage, while lithium iron phosphate offers high safety and long cycle life.
2. Anode Materials: Graphite or other carbon-based materials are typically used as negative electrode materials. Graphite has excellent lithium intercalation properties, good conductivity, and low cost, making it widely used in lithium batteries.
In recent years, silicon-based materials have attracted attention due to their high theoretical capacity, but in practical applications, they still face issues such as volume expansion and cycling stability.
3. Electrolyte: The electrolyte is the medium for lithium ion transport in lithium batteries, and its performance directly affects the battery's capacity, internal resistance, and safety. Commonly used electrolytes include liquid electrolytes composed of organic solvents and lithium salts, as well as solid electrolytes.
4. Diaphragm: The diaphragm is a key component in lithium batteries. It sits between the positive and negative electrodes, isolating them and preventing short circuits. Furthermore, the diaphragm's microporous structure allows lithium ions to pass freely, ensuring the battery's charge and discharge performance.
