Li‐Ion Battery

Lithium-ion battery has been widely used in the portable electric devices, electric vehicles, and hybrid electric vehicles due to its high energy density, high power density, high output voltage, low environmental impact, and long cycle life. It is well known that the energy density of batteries is heavily dependent on the anode and cathode materials and construction. In this chapter, the basic working principles of lithium-ion batteries are introduced firstly, and then the characteristics, key issues as well as the state of the art of the key materials including cathode materials, anode materials, electrolytes, and separators are summarized, and finally the perspectives of the key materials for lithium-ion batteries are proposed. It provides a valuable guidance for the researchers working in the field of lithium-ion batteries.