Electrodes are the basic components of a battery, consisting of a positive electrode and a negative electrode. The key electrode materials for lithium-ion batteries include:
Key components: These are the active materials, which directly participate in the electrochemical reactions. The positive electrode active material in lithium-ion batteries is a lithium intercalation/deintercalation compound, currently including lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, ternary (lithium nickel cobalt manganese oxide), and lithium iron phosphate. Important negative electrode active materials include graphitized carbon materials, amorphous carbon materials, nitrides, silicon-based materials, novel alloys, and other materials. Secondary components: These do not directly participate in the electrode reactions but can improve the battery's conductivity and processing performance. Important components include current collectors, binders, and conductive agents.
Lithium-ion batteries can be classified according to their internal material composition as follows:
Chemical materials: Lithium cobalt oxide (lithium manganese oxide, lithium nickel oxide, ternary materials, lithium iron phosphate), graphite anodes (artificial graphite, natural graphite, MCMB, modified natural graphite), separators, electrolytes, conductive agents (graphite: KS-6, SO; conductive carbon black, such as SuperP, acetylene black, Ketjen black, etc.), PVDF (polyvinylidene fluoride, with a molecular weight ranging from 300,000 to 600,000, the most commonly used binder for cathodes), NMP (N-methylpyrrolidone, a good organic solvent that can quickly dissolve PVDF), oxalic acid (used for surface cleaning and micro-corrosion of copper foil, enhancing the adhesion between the substrate and the binder). SBR (styrene-butadiene rubber, a latex-type binder; SBR is mixed with CMC and used as a water-based binder for negative electrode materials), CMC (sodium carboxymethyl cellulose, pectin, mixed with SBR for dispersion and thickening), PTC (positive temperature coefficient thermistor, insulating above a certain temperature and conducting below that temperature), high-temperature adhesive tape (for mechanical and electrical protection of the electrode ends and tabs, and as a termination strip), copper foil (generally electrolytic copper foil, negative electrode current collector; single and double-sided smooth copper foil are generally formulated with oil-based materials, and double-sided rough copper foil is generally formulated with water-based materials), aluminum foil (calendered aluminum foil, positive electrode current collector), etc.
