The working principle of lithium-ion batteries is the same as that of all secondary electrochemical batteries, that is, the positive and negative electrodes with a certain chemical potential difference realize the reversible release and storage of energy through a controllable redox reaction.

　　The essence of the electrochemical process contained in lithium-ion batteries can be considered to be the conversion of the redox that occurs simultaneously at a chemical site in a chemical reaction into different charge transport carriers to achieve effective separation in physical space.

　　The electronically insulated lithium-ion conductor electrolyte is used to realize the internal positively charged lithium-ion transport, and the negatively charged electrons realize current flow through the external wire, that is, the electrons flow through the external circuit and the lithium ions flow through the internal circuit.

　　Lithium-ion batteries follow the basic structure of traditional electrochemical batteries. The core working components of the battery mainly include four parts: positive electrode, negative electrode, electrolyte and separator. In addition, it also contains other non-core supporting components, such as current collectors, binders, and conductive additives, battery tabs and packaging materials, etc.

　　Unlike other electrochemical batteries, lithium-ion batteries use lithium ions as an energy transmission medium. As shown in the figure, during the charge and discharge process, lithium ions are reversibly inserted and extracted in the layered crystal structure lithium cobalt oxide positive electrode and the layered crystal structure graphite negative electrode. The lithium-containing liquid electrolyte provides the material transport medium, and the external circuit provides electrons. The circuit thus effectively drives the load device to work.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect substitute for lead-acid batteries and are the first choice in the energy storage industry.