Alloys of clathrate allotropes for rechargeable batteries
The present disclosure is directed at an electrode for a battery wherein the electrode comprises clathrate alloys of silicon, germanium or tin. In method form, the present disclosure is directed at methods of forming clathrate alloys of silicon, germanium or tin which methods lead to the formation of empty cage structures suitable for use as electrodes in rechargeable type batteries.
1. An electrode in an electrochemical battery wherein said electrode comprises clathrate alloys of silicon, germanium and/or tin of one of the following formulas:
(a) Type I clathrate alloy A x M y X 46-y , wherein A=Li with none, one or more guest atoms selected from group 1A, group 2A, group 1B, group 2B, group 3B, group 5A, group 7A and group 8; M=Si, Ge, Sn, Al, Cu or Ga; X=Si, Ge and/or Sn wherein M≠X≠A; y is a number value greater than zero; and x is a number value; and
(b) Type II clathrate alloy A x M y X 34-y where A=Li with none, one or more guest atoms from group 1A, group 2A, group 1B, group 2B, group 3B, group 5A, group 7A and group 8; M=B, Al, P, S, Cu, Ni, Zn, Ag, Au, Pt, Ga, Se or any metal or metalloid element capable of forming a clathrate with X; X=Si, Ge or Sn wherein M≠X≠A; y is a number value greater than zero; and x is a number value.
2. The electrode of claim 1 wherein said alloy comprises particles having a largest linear dimension of in the range of 0.1 μm to 100.0 μm.
3. The electrode of claim 1 wherein said electrode comprises a metal substrate and said clathrate alloy is present on the surface of said metal substrate.
4. The electrode of claim 1 wherein lithiation of said alloy results in a volume expansion of less than or equal to 50.0%.
5. The electrode of claim 1 wherein said electrode comprises an anode electrode in a Li battery.
6. The electrode of claim 1 wherein said electrode comprises a cathode electrode in a Li battery.
7. The electrode of claim 1 comprising a Type I clathrate alloy containing an arrangement of 20-atom and 24-atom cages fused together through 5 atom pentagonal rings.
8. The electrode of claim 7 wherein said Type I clathrate alloy has the formula:
A x M y X 46-y .
9. The electrode of claim 1 comprising a Type II clathrate alloy containing an arrangement of 20-atom and 28-atom cages fused together through 5 atom pentagonal rings.
10. The electrode of claim 1 wherein said Type II clathrate alloy has the formula:
A x M y X 34-y .
11. A lithium-ion battery comprising:
an anode containing clathrate alloys of silicon, germanium and/or tin, of one of the following formulas:
(a) Type I clathrate alloy A x M y X 46-y , wherein A=Li with none, one or more guest atoms selected from group 1A, group 2A, group 1B, group 2B, group 3B, group 5A, group 7A and group 8; M=Si, Ge, Sn, Al, Cu or Ga; X=Si, Ge and/or Sn wherein M≠X≠A; y is a number value greater than zero; and x is a number value; and
(b) Type II clathrate alloy A x M y X 34-y where A=Li with none, one or more guest atoms from group 1A, group 2A, group 1B, group 2B, group 3B, group 5A, group 7A and group 8; M=B, Al, P, S, Cu, Ni, Zn, Ag, Au, Pt, Ga, Se or any metal or metalloid element capable of forming a clathrate with X; X=Si, Ge or Sn wherein M≠X≠A; y is a number value greater than zero; and x is a number value;
a cathode; and
an electrolyte.