Lithium battery electrolyte and lithium battery

Abstract

The invention belongs to the field of battery electrolyte, and relates to lithium battery electrolyte and a lithium battery. The lithium battery electrolyte comprises an organic solvent, a lithium salt and organosiloxane, and the organosiloxane is a compound with a specific structure. The organosiloxane has high adsorbability and can be adsorbed on the surface of a negative electrode to form a layer of stable electrolyte interface film, and meanwhile, the organosiloxane also has a flexible Si-O chain and can be reduced by lithium to generate a flexible SEI film, so that the components of the originally generated SEI film are changed, the mechanical modulus and flexibility of the SEI film are enhanced, the electrolyte interface is stable, and the SEI film is excellent; and growth of interface lithium dendrites is effectively inhibited, the cyclic expansion of the negative electrode material is obviously inhibited, and the cycle life of the lithium metal battery is prolonged.

Description

technical field [0001] The invention belongs to the field of battery electrolyte, and in particular relates to a lithium battery electrolyte and a lithium battery. Background technique [0002] Lithium is the metal with the smallest atomic coefficient, has extremely high theoretical specific capacity and extremely low reduction potential (-3.04Vvs. SHE), and has attracted extensive attention from researchers in the field of electrochemistry. However, as a negative electrode material, it still faces many difficulties in practical application, mainly including two aspects: first, it is very easy to have side reactions with the electrolyte, which reduces the Coulombic efficiency of the electrochemical cycle, and the formed SEI film adheres to the electrode / electrolyte The interface also leads to an increase in interface impedance; second, lithium as the negative electrode is accompanied by a serious volume expansion effect during the cycle, and the SEI film is continuously brok...

AI Technical Summary

Problems solved by technology

However, as a negative electrode material, it still faces many difficulties in practical application, mainly including two aspects: first, it is very easy to have side reactions with the electrolyte, which reduces the Coulombic efficiency of the electrochemical cycle, and the formed SEI film adheres to the electrode / electrolyte The interface also leads to an increase in interface impedance; second, lithium as the negative electrode is accompanied by a serious volume expansion effect during the cycle, and the SEI film is continuously broken and formed under stress, and the electrolyte is continuously consumed, causing uneven deposition and continuous Coulombic efficiency. A series of negative effects such as lowering and electrolyte drying up

In particular, the dendritic deposition morphology caused by uneven deposition is the main factor leading to short cycle life and high safety risks of batteries, which greatly limits the commercial application of metal lithium anodes.

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