Composite electrode material and method for manufacturing the same, composite electrode containing the said composite electrode material, and li-based battery

Abstract

Provided are a composite electrode material and a method for manufacturing the same, a composite electrode containing the said composite electrode material, and a li-based battery. The composite electrode material of the present invention comprises: a core, wherein a material of the core is at least one selected from the group consisting of Sn, Sb, Si, Ge, C, a compound thereof and a complex thereof; and a conductive carbon nanoparticle, wherein the conductive carbon nanoparticle grows on a surface of the core.

Description

technical field [0001] The invention belongs to the technical field of lithium batteries, and in particular relates to a composite electrode material and a manufacturing method thereof, a composite electrode containing the same, and a lithium battery. Background technique [0002] Lithium-ion batteries are considered to be one of the most effective ways to store energy today due to their high operating voltage, high energy density, high power, long storage life, and multiple charge and discharge cycles. At present, most of the lithium-ion battery anode materials used commercially are graphite, and its theoretical capacitance value is about 372mAhg -1 However, since a solid electrolyte film (solid electrolyte interphase, SEI) will form on the surface after the first charge, causing irreversible capacitance loss, the actual capacitance value will be lower than the theoretical value. The process of repeated charge and discharge also causes gaps between layers and layers of gra...

AI Technical Summary

Problems solved by technology

At present, most of the lithium-ion battery anode materials used commercially are graphite, and its theoretical capacitance value is about 372mAhg -1 , however, due to the formation of solid electrolyte interphase (SEI) on the surface after the first charge, resulting in irreversible capacitance loss, the actual capacitance value will be lower than the theoretical value

The process of repeated charge and discharge also causes gaps between layers and layers of graphite structure, so that they are separated and broken, and the storage capacity is lost.

With the development of science and technology, pure graphite electrodes can no longer meet the needs of the public

[0003] silicon with up to 4200mAhg -1 The theoretical capacitance value of silicon has been paid more attention in recent years. However, the charge and discharge process of silicon causes a volume change rate as high as 420%, so it is easy to cause silicon itself to be pulverized and fragmented, and the conductive contact between broken silicon is lost. As a result, lithium ions cannot be intercalated and deintercalated smoothly, and the capacity is thus reduced

At the same time, the new surface formed by the fragmented silicon will consume the electrolyte and react with it to form a new SEI film. After multiple charges and discharges, the new SEI film will continue to accumulate inside the battery, resulting in continuous consumption of the electrolyte and shortening the battery life.

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