News

Aluminum foil is used as collector of lithium-ion battery. In general, the lithium-ion battery industry uses rolled aluminum foil as the positive collector. The thickness of rolled foil varies from 10 to 50 microns. The commonly used pure aluminum foil for lithium battery has 1060, 1050, 1145, 1235 and other alloy brands, with - O, H14, - H24, - H22, - H18 and other states.

Lithium battery usually has cylindrical and square shape. The inner part of the battery adopts spiral winding structure. It is made of a very fine and permeable polyethylene film isolation material between the positive and negative electrodes. The positive electrode includes a current collector composed of lithium cobaltite (or nickel cobalt lithium manganate, lithium manganate, lithium ferrous phosphate, etc.) and aluminum foil. The negative electrode consists of a current collector composed of graphitized carbon material and copper foil. The battery is filled with organic electrolyte solution, in addition, it is equipped with safety valve and PTC element (partial cylinder type use), to protect the battery from damage in abnormal state and output short circuit.

Quality requirements

First, the surface color of the aluminum foil for lithium battery is uniform, clean and flat, without obvious roll marks, pockmarks, pinholes and corrosion marks;

Second, the surface of the aluminum foil is free of rolling defects such as creases, speckles, bright lines, etc;

Thirdly, there is no color difference on the surface of aluminum foil;

Fourth, there is no oil on the surface, no serious oil smell, no visible oil spots;

Fifth, the surface tension, dyne pen test is not less than 32 dyne;

Performance characteristics and quality requirements of aluminum foil for lithium battery

Appearance requirements

First, the winding of aluminum foil is moderately elastic, the end face is flat and clean, and the edge is smooth;

Second, the staggered layer of aluminum foil roll shall not exceed ± 1.0mm;

Third, the width of aluminum foil roll tube core is greater than or equal to the width of foil, generally, the length of the two ends of tube core does not exceed the width of foil by 5mm;

Fourth, the aluminum foil should be wound in the center of the tube core;

Fifthly, there are clear joint marks at the two ends of the aluminum coil.