Lithium is the smallest and most active metal on the chemical periodic table. Small in size and high in capacity density, it is widely welcomed by consumers and engineers. However, the chemical properties are too active and pose a very high risk.
When exposed to air, lithium metal can explode with intense oxidation of oxygen. In order to improve safety and voltage, scientists have invented materials such as graphite and lithium cobalt oxide to store lithium atoms. The molecular structure of these materials forms a nanoscale storage grid that can be used to store lithium atoms. In this way, even if the battery casing is broken and oxygen enters, the oxygen molecules are too large to enter these fine cells, so that the lithium atoms do not come into contact with oxygen to avoid an explosion. This principle of lithium-ion batteries allows people to achieve high-density density while achieving safety.
When a lithium-ion battery is charged, the lithium atom of the positive electrode loses electrons and oxidizes to lithium ions. Lithium ions swim through the electrolyte to the negative electrode, enter the cell of the negative electrode, and obtain an electron, which is reduced to a lithium atom. When discharging, the entire program is reversed. In order to prevent the battery from being short-circuited by direct contact between the positive and negative terminals, a separator paper with a large number of fine holes is added to the battery to prevent short circuits. Good diaphragm paper can also automatically close the pores when the battery temperature is too high so that lithium ions can not pass through and prevent danger.