Application of electrolyte additive

Abstract

The invention relates to application of an electrolyte additive. An electrolyte additive is dissolved in a liquid-state electrolyte to form a mixed solution, the mass percent content of the electrolyte additive accounts for 0.5-2% of the liquid-state electrolyte, and the electrolyte additive is selected one or more of mixtures comprising a carboxyl organic substance, a sulfoacid organic substance,a sulfinic acid organic substance, inorganic acid, a thioether organic substance and inorganic ceramic powder. By using a small amount of electrolyte additive in the electrolyte, the electrolyte additive has the advantages of excellent dendritic growth prevention and safety and reliability improvement, the dissolving of transition metal of a positive electrode material caused by high voltage is also prevented, the cycle property and the safety can be substantially improved, and the electrolyte additive is suitable for large-scale application in a liquid-state battery.

Description

technical field [0001] The invention belongs to the field of lithium batteries and relates to an additive, in particular to the application of an electrolyte additive. Background technique [0002] Today, rechargeable lithium batteries are ubiquitous in small portable electronic devices, large-scale electric transportation vehicles, and renewable energy storage systems. In general, liquid lithium-ion batteries now dominate the market. However, there are a series of problems in liquid lithium-ion batteries that need to be solved urgently. For layered and spinel structure oxide cathode materials, the cathode is in a highly oxidized state in the charged state, and a reduction phase transition is prone to occur. The transition metal ions in the framework interact with the solvent in the electrolyte and precipitate into the electrolyte. And diffuse to the negative electrode, catalyze the further growth of the SEI film, and at the same time, the surface structure of the positive...

AI Technical Summary

Problems solved by technology

For lithium metal negative electrodes, the stripping and deposition of lithium during charging and discharging will generate lithium dendrites, which will also cause short circuits in the battery, leading to safety issues.

For other negative electrode materials, due to the slow kinetics of the embedded negative electrode material, metal lithium is directly precipitated on the surface of the negative electrode under low-temperature overcharge or high-current charging, which may cause lithium dendrites and cause micro-short circuits; highly active metal lithium Direct reduction reaction with liquid electrolyte, loss of active lithium and increase of internal resistance

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