Carbon-coated lithium supplementing material as well as preparation method and application thereof

Abstract

The invention discloses a carbon-coated lithium supplementing material as well as a preparation method and application thereof. The carbon-coated lithium supplementing material comprises a lithium-containing compound, an inorganic nonmetal reducing agent and a carbon-containing coating layer partially or completely coating the surface of the lithium-containing compound or / and the inorganic nonmetal reducing agent. According to the carbon-coated lithium supplementing material provided by the invention, agglomeration and growth of the lithium supplementing agent in the synthesis process can be inhibited through carbon coating, the air stability and conductivity of the lithium supplementing agent are improved, the lithium supplementing agent is catalyzed to be decomposed at a relatively low potential to release lithium ions, the lithium supplementing capacity is increased, and the effect of improving the energy density of the battery is achieved; and the carbon-coated lithium supplementing material is simple in preparation process and is beneficial to wide popularization and application. When the carbon-coated lithium supplementing material provided by the invention is added into thepositive electrode of a lithium secondary battery, the irreversible lithium loss of the first charge-discharge negative electrode can be compensated, and the energy density of the battery is improved.The activity of the lithium supplementing material can be improved through surface carbon coating, the air stability is improved, and large-scale application of the lithium supplementing agent in a lithium ion energy storage device is realized.

Description

technical field

[0001] The invention relates to the technical field of energy storage, in particular to a carbon-coated lithium-replenishing material capable of improving the energy density of a lithium-ion battery, and a preparation method and application thereof. Background technique

[0002] Lithium-ion energy storage devices, especially lithium secondary batteries, will form a solid electrolyte interface (SEI) on the surface of the negative electrode during the first cycle, resulting in irreversible lithium loss, resulting in a decrease in the energy density of lithium-ion batteries. The new high-capacity alloy anode material has a low coulombic efficiency (<90%) for the first time, resulting in a large capacity loss in the first week of the battery, and lithium supplementation is required to achieve large-scale application.

[0003] Publication No. "CN1290209C", an invention patent entitled "Dispersion of Lithium Metal in the Negative Electrode of Secondary Batteries...

Images