Silicon-oxygen compound, secondary battery using it, and related battery module, battery pack and device
The present application provide a silicon-oxygen compound, a secondary battery using it, and related battery modules, battery packs, and devices. The silicon-oxygen compound provided by the present application has a formula of SiO x , in which x satisfies 0<x<2. The silicon-oxygen compound contains both sulfur and aluminum element, and the sulfur element is present in an amount of 20 ppm˜300 ppm. The mass ratio of sulfur element to aluminum element is from 1.5 to 13.0. A secondary battery uses the silicon-oxygen compound provided in the present application, so that the secondary battery can have both long-cycle performance and high initial coulombic efficiency.
1. A secondary battery comprising: a positive electrode plate, a negative electrode plate, a separator, and an electrolyte, wherein the negative electrode comprises a negative electrode current collector and a negative electrode film disposed on at least one surface of the negative electrode current collector, the negative electrode film comprises a negative active material comprising a silicon-oxygen compound, wherein the silicon-oxygen compound has a formula of SiO x , in which 0<x<2, the silicon-oxygen compound has an average particle diameter Dv50 of 3 μm to 12 μm, a specific surface area from 1 m 2 /g to 7 m 2 /g, a compacted density measured under a pressure of 5 tons of 1.2 g/cm 3 to 1.7 g/cm 3 , and the silicon-oxygen compound contains both sulfur and aluminum element, and a content of the sulfur element is 20 ppm to 300 ppm; a content of the aluminum element is from 5 ppm to 150 ppm; and a mass ratio of the sulfur element to the aluminum element is from 1.5 to 13.0.
2. The secondary battery according to claim 1 , wherein the content of the sulfur element is from 30 ppm to 250 ppm.
3. The secondary battery according to claim 1 , wherein the content of the aluminum element is from 5 ppm to 45 ppm.
4. The secondary battery according to claim 1 , wherein the mass ratio of the sulfur element to the aluminum element is from 2.0 to 10.0.
5. The secondary battery according to claim 1 , wherein an X-ray diffraction pattern of the silicon-oxygen compound has:
a diffraction peak at a position where the diffraction angle 2θ is 26°-30°, and the full width at half maxima of the diffraction peak is 0.8°-3.2°;
a diffraction peak at a position where the diffraction angle 2θ is 46°-50°, and the full width at half maxima of the diffraction peak is 1.0°-4.2°;
a diffraction peak at a position where the diffraction angle 2θ is 54°-58°, and the full width at half maxima of the diffraction peak is 0.8°-4.5°.
6. The secondary battery according to claim 1 , wherein the silicon-oxygen compound has a powder volume resistivity under a pressure of 20 MPa of 10 Ω cm or less.
7. The secondary battery according to claim 1 , wherein a coating layer is coated on an outer surface of the silicon-oxygen compound, and the coating layer comprises one or more of a polymer, a carbon material, a metal material, and a metal compound.
8. A silicon-oxygen compound, wherein the silicon-oxygen compound has a formula of SiO x , in which 0<x<2, the silicon-oxygen compound contains both sulfur and aluminum element, a content of the sulfur element is 20 ppm to 300 ppm, a content of the aluminum element is from 5 ppm to 150 ppm, and a mass ratio of the sulfur element to the aluminum element is from 1.5 to 13.0,
an X-ray diffraction pattern of the silicon-oxygen compound has:
a first diffraction peak at a position where the diffraction angle 2θ is 26°-30°, and the full width at half maxima of the diffraction peak is 0.8°-3.2°;
a second diffraction peak at a position where the diffraction angle 2θ is 46°-50°, and the full width at half maxima of the diffraction peak is 1.0°-4.2°; and
a third diffraction peak at a position where the diffraction angle 2θ is 54°-58°, and the full width at half maxima of the diffraction peak is 0.8°-4.5°.
9. A device comprising at least one of the secondary battery of claim 1 .
10. The secondary battery according to claim 1 , wherein the content of the aluminum element is from 10 ppm to 100 ppm.
11. The secondary battery according to claim 1 , wherein the silicon-oxygen compound has a powder volume resistivity under a pressure of 20 MPa of 1 Ω·cm or less.
12. The secondary battery according to claim 1 , wherein the silicon-oxygen compound has a specific surface area from 2 m 2 /g to 6 m 2 /g.
13. The secondary battery according to claim 1 , wherein the silicon-oxygen compound has a compacted density measured under a pressure of 5 tons (equivalent to 49 KN) of 1.3 g/cm 3 to 1.6 g/cm 3 .
14. The secondary battery according to claim 7 , wherein the coating layer comprises one or more of Ti 5 Si 3 , Al 2 O 3 , and TiO 2 .
15. A silicon-oxygen compound, wherein the silicon-oxygen compound has a formula of SiO x , in which 0<x<2, the silicon-oxygen compound contains both sulfur and aluminum element, and
an X-ray diffraction pattern of the silicon-oxygen compound has:
a first diffraction peak at a position where the diffraction angle 2θ is 26°-30°, and the full width at half maxima of the diffraction peak is 0.8°-3.2°;
a second diffraction peak at a position where the diffraction angle 2θ is 46°-50°, and the full width at half maxima of the diffraction peak is 1.0°-4.2°; and
a third diffraction peak at a position where the diffraction angle 2θ is 54°-58°, and the full width at half maxima of the diffraction peak is 0.8°-4.5°.
16. The silicon-oxygen compound according to claim 15 , wherein the silicon-oxygen compound has an average particle diameter Dv50 of 2 μm to 15 μm.