Nonaqueous electrolyte secondary battery anode material with a uniform metal-semiconductor alloy layer
The present invention relates to nonaqueous electrolyte secondary batteries and durable anode materials and anodes for use in nonaqueous electrolyte secondary batteries. The present invention also relates to methods for producing these anode materials. In the present invention, a metal-semiconductor alloy layer is formed on an anode material by contacting a portion of the anode material with a displacement solution. The displacement solution contains ions of the metal to be deposited and a dissolution component for dissolving a part of the semiconductor in the anode material. When the anode material is contacted with the displacement solution, the dissolution component dissolves a part of the semiconductor in the anode material thereby providing electrons to reduce the metal ions and deposit the metal on the anode material. After deposition, the anode material and metal are annealed to form a uniform metal-semiconductor alloy layer.
1. A lithium-ion battery comprising an anode, the anode comprising a semiconductor material and a semiconductor alloy layer on the semiconductor material, the semiconductor material comprising silicon, germanium, a III-V compound semiconductor or a II-VI compound semiconductor, the semiconductor alloy layer comprising an alloy of the semiconductor material and a metal selected from nickel, copper, cobalt, silver, gold, platinum, palladium or rhodium, the semiconductor alloy layer having a thickness of about 100 nanometers to about 3 micrometers and a thickness non-uniformity of less than about 25% wherein thickness non-uniformity is defined as the quantity of the maximum thickness minus the minimum thickness, divided by the average thickness.
2. The lithium ion battery of claim 1 wherein the anode comprises a particulate anode material.
3. The lithium ion battery of claim 2 wherein the semiconductor material contains silicon.
4. The lithium ion battery of claim 1 wherein the semiconductor material contains silicon.
5. The lithium ion battery of claim 2 wherein the semiconductor alloy layer comprises an alloy of nickel or copper.
6. The lithium ion battery of claim 1 wherein the semiconductor alloy layer comprises an alloy of nickel or copper.
7. The lithium ion battery of claim 2 wherein the semiconductor alloy layer is a nickel silicide layer.
8. The lithium ion battery of claim 1 wherein the semiconductor alloy layer is a nickel silicide layer.
9. The lithium ion battery of claim 2 wherein the semiconductor alloy layer is a nickel silicide layer having a resistivity of 10-60 μΩ/cm.
10. The lithium ion battery of claim 1 wherein the semiconductor alloy layer is a nickel silicide layer having a resistivity of 10-60 μΩ/cm.
11. A sodium-ion battery comprising an anode, the anode comprising a semiconductor material and a semiconductor alloy layer on the semiconductor material, the semiconductor material comprising silicon, germanium, a III-V compound semiconductor or a II-VI compound semiconductor, the semiconductor alloy layer comprising an alloy of the semiconductor material and a metal selected from nickel, copper, cobalt, silver, gold, platinum, palladium or rhodium, the semiconductor alloy layer having a thickness of about 100 nanometers to about 3 micrometers and a thickness non-uniformity of less than about 25% wherein thickness non-uniformity is defined as the quantity of the maximum thickness minus the minimum thickness, divided by the average thickness.
12. The sodium-ion battery of claim 11 wherein the anode comprises a particulate anode material.
13. The sodium-ion battery of claim 11 wherein the semiconductor material contains silicon.
14. The sodium-ion battery of claim 11 wherein the semiconductor alloy layer comprises an alloy of nickel or copper.
15. The sodium-ion battery of claim 11 wherein the semiconductor alloy layer is a nickel silicide layer.
16. The sodium-ion battery of claim 11 wherein the semiconductor alloy layer is a nickel silicide layer having a resistivity of 10-60 μΩ/cm.
17. A potassium-ion battery comprising an anode, the anode comprising a semiconductor material and a semiconductor alloy layer on the semiconductor material, the semiconductor material comprising silicon, germanium, a III-V compound semiconductor or a II-VI compound semiconductor, the semiconductor alloy layer comprising an alloy of the semiconductor material and a metal selected from nickel, copper, cobalt, silver, gold, platinum, palladium or rhodium, the semiconductor alloy layer having a thickness of about 100 nanometers to about 3 micrometers and a thickness non-uniformity of less than about 25% wherein thickness non-uniformity is defined as the quantity of the maximum thickness minus the minimum thickness, divided by the average thickness.
18. The potassium-ion battery of claim 17 wherein the anode comprises a particulate anode material.
19. The potassium-ion battery of claim 17 wherein the semiconductor material contains silicon.
20. The potassium-ion battery of claim 17 wherein the semiconductor alloy layer comprises an alloy of nickel or copper.
21. The potassium-ion battery of claim 17 wherein the semiconductor alloy layer is a nickel silicide layer.
22. The potassium-ion battery of claim 17 wherein the semiconductor alloy layer is a nickel silicide layer having a resistivity of 10-60 μΩ/cm.
23. The lithium ion battery of claim 1 wherein the semiconductor alloy layer is reversibly lithiated during charge and discharge cycling of the lithium ion battery.
24. The lithium ion battery of claim 23 wherein the semiconductor material contains silicon.
25. The lithium ion battery of claim 24 wherein the semiconductor alloy layer comprises an alloy of nickel or copper.
26. The lithium ion battery of claim 23 wherein the semiconductor alloy layer comprises an alloy of nickel or copper.
27. The lithium ion battery of claim 23 wherein the semiconductor alloy layer is a nickel silicide layer.
28. The lithium ion battery of claim 23 wherein the semiconductor alloy layer is a nickel silicide layer having a resistivity of 10-60 μΩ/cm.
29. The lithium ion battery of claim 1 wherein the semiconductor alloy layer is a nickel silicide layer and the nickel silicide layer is formed by a process comprising the step of selectively etching the nickel silicide layer to remove excess nickel without etching the nickel silicide layer.