A negative electrode active material and a method for manufacturing the same
Patent Information
- Application Number
- CN202210562930.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-05-23
- Publication Date
- 2026-08-28
- Estimated Expiration
- 2042-05-23
AI Technical Summary
但是，硅基负极本身的低离子电导率和低电子电导率影响了锂离子的快速脱嵌性能，而且微米硅有着极大的体积膨胀，易于破碎粉化，使得其应用也收到很大限制
[0016]本发明提出了一种负极活性材料，通过微米硅双层石墨烯渗透包覆有效的缓解材料体积膨胀，同时外层石墨烯薄层具有良好延展性能够具有更广泛的应用，包括用于固态电池中，能够有效提升首周循环效率和循环性能。当应用于全固态电池中，利用石墨烯薄层的良好延展性改善了与固态电解质的界面问题，可有效的避免固态电解质界面(SEI)膜的生成，提升了电化学装置的安全性能和使用寿命。
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Figure CN117154023B_ABST
Abstract
Claims
1. A negative electrode active material, characterized in that, The negative electrode active material includes micron-sized silicon and a bilayer graphene material coated with micron-sized silicon; wherein, the first graphene material forms a first mixed phase with the micron-sized silicon, the first mixed phase is heat-treated to form a second mixed phase, and then forms a third mixed phase with the second graphene material, the third mixed phase is then heat-treated to form the negative electrode active material; the first graphene material accounts for 10%-30% of the mass percentage of the first mixed phase; the second graphene material accounts for 5%-20% of the mass percentage of the third mixed phase.
2. The negative electrode active material according to claim 1, characterized in that, The first graphene material has 2-10 layers, and the size of each layer is ≤45μm; the second graphene material has 1-9 layers, and the size of each layer is ≤65μm; the number of layers in the second graphene material is less than the number of layers in the first graphene material; and the size of each layer in the second graphene material is greater than the size of each layer in the first graphene material.
3. The negative electrode active material according to claim 1, characterized in that, The Dv50 of the micron-sized silicon is 1μm≤Dv50≤5μm.
4. A method for preparing the negative electrode active material according to any one of claims 1-3, characterized in that, The preparation method includes: Micron-sized silicon and the first graphene material were mixed in a certain proportion and then spray-dried to obtain the first mixed phase; The first mixed phase was heat-treated at 600℃-1000℃ under a nitrogen atmosphere to obtain the second mixed phase; The second mixed phase and the second graphene material were mixed in a certain proportion and spray-dried to obtain the third mixed phase; The third mixed phase was heat-treated at 600℃-1000℃ in a nitrogen atmosphere, and then subjected to graded demagnetization to obtain the negative electrode active material.
5. The preparation method according to claim 4, characterized in that, The heat treatment time for the first mixed phase is 2-12 hours; The heat treatment time for the second mixed phase is 2-12 hours.
Citation Information
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