Alloy compositions for lithium ion batteries

1. A lithium ion battery comprising a cathode, an anode, and an electrolyte in electrical communication with the anode and the cathode, wherein the anode comprises an alloy composition comprising

a) silicon in an amount of 35 to 70 mole percent;

b) aluminum in an amount of 1 to 45 mole percent;

c) a transition metal in an amount of 5 to 25 mole percent;

d) tin in an amount of 1 to 15 mole percent; and

e) a fifth element comprising yttrium, a lanthanide element, an actinide element, or a combination thereof in an amount of 2 to 15 mole percent,

wherein each mole percent is based on a total number of moles of all elements except lithium in the alloy composition; and

wherein the alloy composition is a mixture of an amorphous phase comprising silicon and a nanocrystalline phase comprising an intermetallic compound of tin and the fifth element.

2. The lithium ion battery of claim 1 , wherein the amorphous phase further comprises aluminum and the transition metal.

3. The lithium ion battery of claim 1 , wherein the fifth element comprises cerium, lanthanum, praseodymium, neodymium, or a combination thereof.

4. The lithium ion battery of claim 1 , wherein the nanocrystalline phase is substantially free of tin in an elemental form.

5. The lithium ion battery of claim 1 , wherein the alloy composition further comprises less than 1 mole percent alkaline earth metal.

6. The lithium ion battery of claim 1 , wherein the alloy composition further comprises an alkaline metal.

7. The lithium ion battery of claim 1 , wherein the alloy composition comprises particles having a maximum average dimension of 1 to 60 micrometers.

8. The lithium ion battery of claim 1 , wherein the alloy composition has a single amorphous phase and a single nanocrystalline phase.

9. The lithium ion battery of claim 1 , wherein the alloy composition is of Formula I

Si a Al b T c Sn d M e Li f   (I)

wherein

a is a number in the range of 35 to 70;

b is a number in the range of 1 to 45;

T is a transition metal;

c is a number in the range of 5 to 25;

d is a number in the range of 1 to 15;

M is yttrium, a lanthanide element, an actinide element, or a combination thereof;

e is a number in the range of 2 to 15;

the sum of a+b+c+d+e is equal to 100; and

f is a number in the range of 0 to [4.4(a+d)+b].

10. The lithium ion battery of claim 9 , wherein the variable a is a number in the range of 40 to 65; b is a number in the range of 1 to 25; c is a number in the range of 5 to 25; d is a number in the range of 1 to 15; and e is a number in the range of 2 to 15.

11. The lithium ion battery of claim 9 , wherein the variable a is a number in the range of 35 to 55; b is a number in the range of 25 to 45; c is a number in the range of 5 to 25; d is a number in the range of 1 to 15; and e is a number in the range of 2 to 15.

12. The lithium ion battery of claim 9 , wherein the variable a is a number in the range of 55 to 65; b is a number in the range of 10 to 20; c is a number in the range of 5 to 25; d is a number in the range of 1 to 15; and e is a number in the range of 2 to 15.

13. The lithium ion battery of claim 9 , wherein the anode further comprises an organic binder comprising a polyimide.

14. The lithium ion battery of claim 1 , wherein the anode further comprises lithium metal.

15. A battery pack comprising at least one lithium ion battery according to claim 1 .

16. The lithium ion battery of claim 1 , wherein the nanocrystalline phase is substantially free of silicon.

17. A method of preparing a lithium ion battery, said method comprising:

providing an alloy composition comprising

a) silicon in an amount of 35 to 70 mole percent;

b) aluminum in an amount of 1 to 45 mole percent;

c) a transition metal in an amount of 5 to 25 mole percent;

d) tin in an amount of 1 to 15 mole percent; and

e) yttrium, a lanthanide element, an actinide element, or a combination thereof in an amount of 2 to 15 mole percent,

wherein each mole percent is based on a total number of moles of all elements except lithium in the alloy composition and wherein the alloy composition is a mixture of an amorphous phase comprising silicon and a nanocrystalline phase comprising an intermetallic compound of tin and the fifth element;

providing a cathode and an electrolyte, wherein the electrolyte is in electrical communication with both the cathode and the anode.

18. The method of claim 17 , wherein providing the alloy composition comprises melt spinning the silicon, aluminum, tin, transition metal element, and fifth element.

19. The method of claim 17 , wherein providing the alloy composition comprises initially forming a totally amorphous precursor material and then annealing the precursor material to prepare the mixture of the amorphous phase and the nanocrystalline phase.

20. The method of claim 17 , wherein providing the alloy comprises

forming a precursor material that comprises

i) amorphous material;

ii) the nanocrystalline phase comprising tin and the fifth element; and

iii) crystalline elemental tin; and

annealing the precursor material to remove the crystalline elemental tin.

21. The method of claim 17 , wherein the nanocrystalline phase is substantially free of silicon.

22. An alloy composition comprising

a) silicon in an amount of 35 to 70 mole percent;

b) aluminum in an amount of 1 to 45 mole percent;

c) a transition metal in an amount of 5 to 25 mole percent;

d) tin in an amount of 1 to 15 mole percent; and

e) a fifth element comprising yttrium, a lanthanide element, an actinide element, or a combination thereof in an amount of 2 to 15 mole percent,

wherein each mole percent is based on a total number of moles of all elements except lithium in the alloy composition; and

wherein the alloy composition is a mixture of an amorphous phase comprising silicon and a nanocrystalline intermetallic compound of tin and the fifth element.

23. The alloy composition of claim 22 , wherein the nanocrystalline phase is substantially free of silicon.