Protective composite battery separator and electrochemical device component with red phosphorus
Disclosed are ionically conductive membranes for protection of active metal anodes and methods for their fabrication. The membranes may be incorporated in active metal negative electrode (anode) structures and battery cells. In accordance with the invention, the membrane has the desired properties of high overall ionic conductivity and chemical stability towards the anode, the cathode and ambient conditions encountered in battery manufacturing. The membrane is capable of protecting an active metal anode from deleterious reaction with other battery components or ambient conditions while providing a high level of ionic conductivity to facilitate manufacture and/or enhance performance of a battery cell in which the membrane is incorporated.
1. A protective composite battery separator, consisting essentially of:
an ionically conductive first material layer precursor comprising red phosphorus; and
a second material layer in contact with the first layer, the second material selected from the group consisting of ceramic metal ion conductors and glass ceramic active metal ion conductors;
wherein the ionic conductivity of the composite separator is at least 10 −4 S/cm.
2. The separator of claim 1 , wherein the second material layer is a sintered material having a thickness of about 10 to 1000 microns.
3. The separator of claim 1 , wherein the ionic conductivity of the second material layer is about 10 −3 S/cm.
4. The separator of claim 1 , wherein the thickness of the first material layer precursor is about 0.1 to 5 microns.
5. The separator of claim 1 , wherein the thickness of the second material layer is about 0.1 to 1000 microns.
6. The separator of claim 1 , wherein the ionic conductivity of the second material layer is between 10 −4 and 10 −3 S/cm and the thickness of the second material layer is about 10 to 500 microns.
7. The separator of claim 6 , wherein the thickness of the second material layer is 10 to 100 microns.
8. The separator of claims 1 , wherein the second layer comprises a material selected from the group consisting of glass-ceramic active metal ion conductors, lithium beta-alumina, LISICON, sodium beta-alumina and NASICON.
9. The separator of claim 1 , wherein the second layer is an ion conductive glass-ceramic having the following composition:
Composition
mol %
P 2 O 5
26-55%
SiO 2
0-15%
GeO 2 + TiO 2
25-50%
in which GeO 2
0-50%
TiO 2
0-50%
ZrO 2
0-10%
M 2 O 3
0-10%
Al 2 O 3
0-15%
Ga 2 O 3
0-15%
Li 2 O
3-25%
and containing a predominant crystalline phase composed of Li 1+x (M,Al,Ga) x (Ge 1−y Ti y) 2−x (PO 4 ) 3 where X≦0.8 and 0≦Y≦1.0, and where M is an element selected from the group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb and/or Li 1+x+y Q x Ti 2−x Si y P 3−y O 12 where 0<X≦0.4 and 0<Y≦0.6, and where Q is Al or Ga.
10. An electrochemical device component, comprising:
an active metal negative electrode having a first surface and a second surface; and
a protective composite separator as claimed in claim 1 on the first surface of the electrode and having a smooth gap-free interface therewith.
11. The component of claim 10 , wherein the active metal of the electrode is an alkali metal.
12. The component of claim 10 , wherein the active metal of the electrode is lithium or a lithium alloy.
13. The component of claim 10 , wherein the second layer is an ion conductive glass-ceramic having the following composition:
Composition
mol %
P 2 O 5
26-55%
SiO 2
0-15%
GeO 2 + TiO 2
25-50%
in which GeO 2
0-50%
TiO 2
0-50%
ZrO 2
0-10%
M 2 O 3
0-10%
Al 2 O 3
0-15%
Ga 2 O 3
0-15%
Li 2 O
3-25%
and containing a predominant crystalline phase composed of Li 1+x (M,Al,Ga) x (Ge 1−y Ti y) 2−x (PO 4 ) 3 where X≦0.8 and 0≦Y≦1.0, and where M is an element selected from the group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb and/or Li 1+x+y Q x Ti 2−x Si y P 3−y O 12 where 0<X≦0.4 and 0<Y≦0.6, and where Q is Al or Ga.
14. The component of claim 13 , further comprising a positive electrode chosen from a sulfur-based positive electrode, a metal oxide based positive electrode, and a metal sulfide based positive electrode in contact with said second layer material.
15. The component of claim 10 , wherein a first layer comprises a composite in situ reaction product of the first material layer precursor and active metal of the negative electrode.
16. The component of claim 15 , wherein the active metal of the negative electrode is lithium or a lithium alloy.