Electrolyte for lithium-air battery and corresponding battery product

Abstract

The invention discloses a lithium-air battery. The lithium-air battery comprises an air positive electrode, a lithium negative electrode and organic electrolyte which is filled between the air positive electrode and the lithium negative electrode, the organic electrolyte contains an aprotic organic solvent, lithium salt and a soluble catalyst, the soluble catalyst can select from phthalocyanine transitional metal compound and derivatives thereof, such as iron phthalocyanine and carboxylation or sulfated iron phthalocyanine. The invention also discloses electrolyte for the corresponding lithium-air battery. Through the electrolyte, a solution-phase catalytic system can be provided for the inside of the lithium-air battery, and thus even if a great amount of solid lithium oxide or lithium peroxide is formed on the surface of the air positive electrode, the favorable contact between the catalyst and a reactant can be guaranteed, the charging voltage of the lithium-air battery can be correspondently reduced, the discharging voltage can be increased, the rate capacity performance of the battery also can be improved, the capacity can be increased, and the cycling performance of the battery can be improved.

Description

technical field [0001] The invention belongs to the technical field of lithium batteries, and more specifically relates to an electrolyte solution for lithium-air batteries and corresponding battery products. Background technique [0002] A lithium-air battery is a battery that uses lithium as the negative electrode and oxygen or pure oxygen in the air as the positive electrode reactant. Since oxygen can be obtained from the environment without being stored in the battery, it has a higher energy density than lithium-ion batteries, so it has become a research and development hotspot worldwide in recent years, and is expected to become a new generation of secondary batteries. The basic working principle of lithium-air batteries is: Oxygen reduction reaction (ORR) occurs during discharge. At this time, the lithium on the negative electrode releases electrons and becomes Li+. Li+ passes through the electrolytic material and combines with oxygen and electrons flowing from the ext...

AI Technical Summary

Problems solved by technology

These catalysts exist in solid form. Although they are still effective for the discharge and charge reactions of lithium-air batteries, the efficiency does not meet the requirements. One of the important reasons is that the contact between the catalyst and the reactant is a prerequisite for its catalytic effect, while The discharge product of lithium-air batteries - lithium oxide is also a solid

In this way, during the discharge process, the lithium oxide generated by the reaction will adhere to the surface of the catalyst, hindering the further contact between the reactant and the catalyst, and affecting the ORR reaction; while during the charging process, the lithium oxide that is in direct contact with the catalyst surface After decomposing to generate oxygen, most of the remaining lithium oxides that are not in direct contact with the catalyst surface will not be catalyzed, resulting in a high overpotential of the OER reaction, and the reaction is not complete, and the battery cycle performance is deteriorated.