Negative electrode active material and use of secondary lithium battery

Abstract

The invention has a grain structure with an outer shell and several inner cores. The grain size is from 100 nanometers to 100 microns. The inner cores are compound grain that includes active substance and conducting additive. The outer shell is a carbon layer. The active substance takes 20-95wt% of total cathode active material, and is mixture of one or several transition metallic compound selected from silicon and lithium storage whose thermodynamic equilibrium potential is less than 1.5v. The cathode material can be made by using mechanical process or thermal method, and can be directly used as cathode material or used with other existing cathode material.

Description

technical field

[0001] The invention relates to a negative electrode material for a lithium battery, in particular to a negative electrode active material for a secondary lithium battery and its use. Background technique

[0002] Among the negative electrode active materials of the secondary lithium battery, the theoretical specific capacity of metal lithium is 3830mAh / g, so the energy density of the secondary lithium battery using metal lithium as the negative electrode active material is the highest. However, dendrite growth occurs in the negative electrode of the metal secondary lithium battery during charging and discharging, which causes the internal short circuit of the battery, causing the battery to burn or even explode. In order to improve its safety, from the early 1970s to the end of the 1980s, lithium alloys such as lithium aluminum, lithium silicon, lithium lead, lithium tin, and lithium cadmium were used to replace metallic lithium as negative electrode active ...

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