Lithium-ion battery is a kind of secondary battery system, in which two different lithium intercalation compounds which can reversibly intercalate and deintercalate lithium ions are used as the anode and cathode of the battery respectively. When charging, lithium ions emerge from the lattice of the cathode material, and are inserted into the lattice of the cathode material after passing through the electrolyte, so that the cathode is rich in lithium and the cathode is poor in lithium; During the discharge process, lithium ions are extracted from the lattice of the negative electrode material and inserted into the 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 poor in lithium. In this way, when lithium ions are embedded and extracted, the potential difference between anode and cathode materials relative to metallic lithium is the working voltage of the battery.

Lithium-ion battery is a new generation of green high-energy battery with excellent performance, which has become one of the focuses of high-tech development. Lithium-ion battery has the following characteristics: high voltage, high capacity, low consumption, no memory effect, no pollution, small volume, small internal resistance, less self-discharge and more cycles. Due to the above characteristics, lithium-ion batteries have been used in many civil and military fields, such as mobile phones, notebook computers, video cameras and digital cameras.