Aluminium cathode foil for lithium ion battery used 1235 aluminum foil with accurate thickness and clean surface. The four important parts of lithium-ion batteries are positive electrode material, negative electrode material, separator and electrolyte. Battery aluminum foil have the advantages of good electrical conductivity, oxidation protection film has been formed, soft texture is conducive to bonding, mature manufacturing technology, and relatively low price, so they are selected as important materials for lithium-ion battery current collectors.
At present, general aluminium cathode foil for lithium ion battery products generally require a strength of ≧180Mpa, and it is pure aluminum alloy, which means that battery aluminum foil is a product that has extremely strict requirements on the base material of aluminum foil, and battery aluminium foil requires the thinnest thickness and highest strength, the highest surface dyne value, the smallest thickness difference, the best plate shape and the cleanest surface.
1235 aluminum foil, 1060 aluminum foil, etc. are widely used on aluminum foils for lithium-ion batteries. The aluminum cathode foil for lithium ion battery products have uniform surface color, clean, flat plate shape, no obvious oil stains; strength > 180Mpa, elongation > 1.5%, wettability > 32 Dyne can effectively improve the adhesion between the active material and the current collector and reduce the manufacturing cost.
Why use aluminum foil for the cathode of lithium-ion batteries?
First, aluminum foil has good conductivity, soft texture and cheap price. Among ordinary materials, metal materials are the materials with the best electrical conductivity, and aluminum foil are the cheapest and best electrical conductors among metal materials. Compared with winding, the pole piece used to prepare the battery must have a certain degree of flexibility, so as to ensure that the pole piece will not be brittle and broken during winding. Among metal materials, aluminum foil are also soft metals. The last is to consider the cost of battery preparation. Relatively speaking, the price of aluminum foil is relatively cheap.
Second, aluminum foil is relatively stable in the air. Aluminum is easy to chemically react with oxygen in the air, forming a dense oxide film on the surface of aluminum to prevent further reaction of aluminum, and this thin oxide film also has a certain protective effect on aluminum in the electrolyte.