The lithium ion battery is a battery system in which two different lithium intercalation compounds capable of reversibly inserting and extracting lithium ions are used as the positive electrode and the negative electrode of the battery.
During charging, lithium ions are extracted from the crystal lattice of the positive electrode material, and inserted into the crystal lattice of the negative electrode material after passing through the electrolyte, so that the negative electrode is rich in lithium and the positive electrode is poor in lithium.
During discharge, lithium ions are extracted from the crystal lattice of the negative electrode material, and inserted into the crystal lattice of the positive electrode material after passing through the electrolyte, so that the positive electrode is rich in lithium and the negative electrode is depleted in lithium.
In this way, the difference between the potential of the positive and negative electrodes when inserting and extracting lithium ions relative to the metal lithium is the operating voltage of the battery.
Lithium-ion batteries are a new generation of green high-energy batteries with excellent performance and have become one of the focuses of high-tech development. Lithium-ion batteries have the following characteristics: high voltage, high capacity, low consumption, no memory effect, no pollution, small size, low internal resistance, less self-discharge, and more cycles.
Because of the above-mentioned characteristics, lithium-ion batteries have been applied to many civilian and military fields such as mobile phones, notebook computers, video cameras, and digital cameras.
Important constituent materials of lithium-ion batteries include electrolyte, separator materials, positive and negative electrode materials and so on. Cathode materials occupies a large proportion. The performance of the cathode material directly affects the performance of lithium-ion batteries, and its cost directly determines the cost of the battery.
The battery aluminium foil is used as the current collector of the lithium ion battery. Normally, the lithium-ion battery industry uses rolled aluminum foil as the positive electrode current collector. The battery aluminium foil not only has strict performance requirements, but also has high requirements on surface quality, size, and cutting accuracy. The common alloys of lithium ion battery aluminum foil are 1060,1070, 1100, 1235 and 3003.