Negative electrode active material for lithium secondary battery and lithium secondary battery comprising same
By using carbon-based particles with pore structure and composite particles containing silicon-containing coating in the negative electrode active material of lithium secondary batteries, the problem of cracks that are prone to occur during charging and discharging of the negative electrode active material is solved, and the battery life is extended and the capacity retention rate is improved.
Patent Information
- Application Number
- CN202411678046.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-30
- Filing Date
- 2024-11-22
- Publication Date
- 2025-05-30
AI Technical Summary
The negative electrode active substances of lithium secondary batteries are prone to cracks during repeated charging and discharging, resulting in a shortening of battery life.
The negative electrode active material containing composite particles is used. The composite particles are composed of carbon-based particles and a silicon-containing coating. The carbon-based particles have a porous structure. The silicon-containing coating is formed on the surface of the carbon-based particles. The structure of the composite particles is optimized by a specific peak distance and peak intensity ratio.
It improves the physical and chemical stability of composite particles, extends the life of lithium secondary batteries, and improves the capacity retention rate of the battery.
Smart Images
Figure CN120072880A_ABST
Abstract
Claims
1. A negative electrode active material for a lithium secondary battery, the negative electrode active material for a lithium secondary battery comprising composite particles, the composite particles comprising: a carbon-based particle comprising pores; and a silicon-containing coating formed on the surface of the carbon-based particles, in, The peak distance of the composite particles defined by the following formula 1 is 0.6 Å or less, [Formula 1] Peak distance (Å) = p2-p1 In Formula 1, p1 is the central peak value of the peak with the maximum height in the range of 3.4Å to 4.1Å of the PDF spectrum obtained by analyzing the PDF of the composite particles, and p2 is the central peak value of the peak with the maximum height in the range of 4.1Å to 4.9Å of the PDF spectrum.
2. The negative electrode active material for lithium secondary battery according to claim 1, wherein The peak distance is 0.56 Å to 0.59 Å.
3. The negative electrode active material for lithium secondary battery according to claim 1, wherein The peak distance is 0.57 Å to 0.59 Å.
4. The negative electrode active material for lithium secondary battery according to claim 1, wherein The peak intensity ratio of the composite particles defined by the following formula 2 is 0.1 to 0.35, [Formula 2] Peak intensity ratio = Ip2 / Ip1 In Formula 2, Ip1 is the maximum height of a peak within the range of 3.4 Å to 4.1 Å of a PDF spectrum obtained by PDF analysis of the composite particles, and Ip2 is the maximum height of a peak within the range of 4.1 Å to 4.9 Å of the PDF spectrum.
5. The negative electrode active material for lithium secondary battery according to claim 4, wherein The peak intensity ratio is 0.13 to 0.
29.
6. The negative electrode active material for lithium secondary battery according to claim 4, wherein The peak intensity ratio is 0.15 to 0.
28.
7. The negative electrode active material for lithium secondary battery according to claim 1, wherein The pores of the carbon-based particles have a size of 0.1 nm to 10 nm.
8. The negative electrode active material for lithium secondary battery according to claim 1, wherein The pores of the carbon-based particles have a size of 1 nm to 5 nm.
9. The negative electrode active material for lithium secondary battery according to claim 1, wherein The composite particle further includes a carbon coating formed on the silicon-containing coating.
10. The negative electrode active material for lithium secondary battery according to claim 9, wherein The carbon coating layer includes at least one selected from amorphous carbon and a conductive polymer.
11. The negative electrode active material for lithium secondary battery according to claim 1, wherein The pores of the carbon-based particles include a shape bent from the outermost portion of the carbon-based particles toward the inner portion of the carbon-based particles.
12. A lithium secondary battery comprising: A negative electrode, the negative electrode comprising the negative electrode active material for a lithium secondary battery according to claim 1; as well as A positive electrode is arranged opposite to the negative electrode.