Lithium-ion batteries use carbon materials as the negative electrode and lithium-containing compounds as the positive electrode. There is no metallic lithium, only lithium ions. This is a lithium-ion battery. Lithium-ion battery refers to a general term for batteries with lithium-ion intercalation compounds as positive electrode materials. The charging and discharging process of lithium-ion batteries is the process of lithium-ion intercalation and deintercalation. In the process of intercalation and deintercalation of lithium ions, it is accompanied by the intercalation and deintercalation of electrons equivalent to lithium ions (usually the positive electrode is represented by intercalation or deintercalation, and the negative electrode is represented by intercalation or deintercalation). During the charging and discharging process, lithium ions are intercalated/deintercalated and intercalated/deintercalated back and forth between the positive and negative electrodes, which is vividly called "rocking chair battery".