KR-20260064354-A - Negative electrode active material for secondary battery, method for preparing the same and lithium secondary battery including the same

Abstract

One embodiment of the present invention provides a negative electrode active material for a secondary battery comprising: a core containing silicon-based particles; and a shell located on the core containing silicon (Si), nitrogen (N) and oxygen (O), wherein the shell comprises a Si 2 N 2 O phase and a Si 3 N 4 phase.

Inventors

• 서유경
• 이동욱
• 전민영
• 이총민
• 채태성

Assignees

• 주식회사 에코프로비엠

Dates

Publication Date

20260507

Application Date

20241031

Claims (4)

1. A core containing silicon-based particles; and It comprises a shell located on the above core and containing silicon (Si), nitrogen (N) and oxygen (O), and The above shell is a negative electrode active material for a secondary battery comprising a Si₂N₂O phase and a Si₃N₄ phase .
2. In paragraph 1, A negative electrode active material for a secondary battery, wherein, with respect to the total weight of the core and shell, the total sum of nitrogen (N) and oxygen (O) (N+O) is 12 weight% or less and the weight ratio (N/O) is 1 to 10%.
3. A negative electrode for a secondary battery comprising a negative electrode active material according to claim 1.
4. A secondary battery comprising a negative electrode according to paragraph 3.

Description

Negative electrode active material for secondary battery, method for preparing the same and lithium secondary battery including the same The present invention relates to a negative electrode active material for a secondary battery, a method for manufacturing the same, and a lithium secondary battery including the same. With the recent increase in demand for electronic devices, including mobile phones, technological development for these devices is expanding. Consequently, the demand for lithium-ion batteries, such as lithium batteries, lithium-ion batteries, and lithium-ion polymer batteries, is rising significantly as power sources for these electronic devices. Furthermore, driven by the global trend of tightening regulations on vehicle fuel efficiency and exhaust emissions, the growth of the electric vehicle (EV) market is accelerating. Along with this, demand for medium- and large-sized secondary batteries, such as those for EVs and Energy Storage Systems (ESS), is expected to surge. Meanwhile, as the demand for higher capacity in secondary batteries, such as medium and large-sized batteries, has recently increased, silicon-based anode materials with excellent theoretical capacity are being researched as anode materials for secondary batteries. However, silicon-based anode materials cause significant volume changes during lithium insertion and extraction, leading to electrical delamination due to silicon particle pulverization and reversible capacity loss under repeated cycles. The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which the present invention pertains. Throughout the specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. Additionally, when a part such as a layer, film, region, plate, etc. is described in this specification as being “on” or “on” another part, this includes not only cases where it is “immediately on” another part, but also cases where there is another part in between. In this specification, "A to B" means "A or more and B or less" unless specifically defined otherwise. Additionally, "A and/or B" means at least one selected from the group consisting of A and B, unless specifically defined otherwise. One embodiment of the present invention provides a negative electrode active material for a secondary battery comprising: a core containing silicon-based particles; and a shell located on the core containing silicon (Si), nitrogen (N) and oxygen (O), wherein the shell comprises a Si 2 N 2 O phase and a Si 3 N 4 phase. One embodiment of the present invention provides a negative electrode active material for a secondary battery comprising: a core containing silicon-based particles; and a shell positioned on the core containing silicon (Si), nitrogen (N), and oxygen (O), wherein the total sum (N+O) of nitrogen (N) and oxygen (O) is 12 weight% or less and the weight ratio (N/O) is 1 to 10% with respect to the total weight of the core and the shell. Specifically, silicon-based particles have the advantage of high capacity compared to conventional graphite anode active materials; however, it is analyzed that the destruction of the conductive network caused by the particle fragmentation and pulverization due to expansion and contraction during the absorption and release of lithium ions is the cause of reduced cycle life. In the present invention, expansion and contraction can be buffered by forming a high-area ceramic shell containing silicon, nitrogen, and oxygen on silicon-based particles. Furthermore, a compound containing silicon (Si), nitrogen (N), and oxygen (O) participates in the reaction with lithium ions during charging and discharging to increase lithium mobility, thereby consequently improving cycle life. Additionally, with respect to the total weight of the core and shell, the total amount of nitrogen (N) and oxygen (O) may be 10 weight% or less, specifically, the total amount of nitrogen (N) and oxygen (O) may be 7 weight% or less, 6 weight%, 5 weight%, 4 weight%, 3.5 weight% or less, or 3 weight% o