Solid state battery

Abstract

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 solid state battery, comprising:
 a solid anode comprising lithium;   a solid cathode comprising a material selected from the group consisting of metal oxide based cathodes, metal sulfide based cathodes and active sulfur cathodes;   a solid protective membrane having lithium ion conductivity of at least 10 −7  S/cm on the first surface of the anode, the membrane being substantially impervious, chemically compatible with lithium on a surface in contact with the anode, and chemically compatible with the cathode on an opposite second surface; and   a solid polymer electrolyte disposed between the second surface of the protective membrane and the cathode.   
     
     
         2 . The battery cell of  claim 1 , wherein the anode is lithium metal. 
     
     
         3 . The battery cell of  claim 1 , wherein the anode is a lithium metal alloy. 
     
     
         4 . The battery cell of  claim 1 , wherein the solid protective membrane is monolithic. 
     
     
         5 . The battery cell of  claim 1 , wherein the solid protective membrane comprises a composite comprising,
 a first component in contact with the anode, the first component being conductive to lithium ions chemically compatible with lithium, and   a second component in contact with the first component, the second component being substantially impervious, conductive to lithium ions and chemically compatible with the first material component and the cathode.   
     
     
         6 . The battery cell of  claim 5 , wherein the first component comprises a material selected from the group consisting of Li 3 N, Li 3 P and LiI, LiBr, LiCl, LiF, LiPON. 
     
     
         7 . The battery cell of  claim 5 , wherein the first component is an in situ composite reaction product of lithium with one selected from the group consisting of metal nitride, silicon nitride, metal halide, metal phosphide, red phosphorus, a wetting layer coated on LiPON. 
     
     
         8 . The battery cell of  claim 5 , wherein the substantially impervious ionically conductive layer comprises a material selected from the group consisting of glassy or amorphous active metal ion conductors, ceramic active metal ion conductors, and glass-ceramic active metal ion conductors. 
     
     
         9 . The battery cell of  claim 1 , wherein the solid polymer electrolyte comprises polyethylene oxide (PEO). 
     
     
         10 . The battery cell of  claim 1 , wherein the cathode is a lithiated metal oxide based cathode. 
     
     
         11 . The battery cell of  claim 10 , wherein, the lithiated metal oxide based cathode is selected from the group consisting of Li x CoO 2 , Li x NiO 2 , Li x Mn 2 O 4  and LiFePO 4 . 
     
     
         12 . The battery cell of  claim 1 , wherein the cathode is an unlithiated metal oxide based cathode. 
     
     
         13 . The battery cell of  claim 12 , wherein the cell is a secondary cell and the unlithiated metal oxide based cathode is selected from the group consisting of AgxV 2 O 5 , CuxV 2 O 5 , V 2 O 5  and V 6 O 13 . 
     
     
         14 . The battery cell of  claim 12 , wherein the cell is a primary cell and the unlithiated metal oxide based cathode is selected from the group consisting of AgxV 2 O 5 , CuxV 2 O 5 , V 2 O 5  and V 6 O 13 , MnO 2 , CuO, Ag 2 CrO 4  and MoO 3 . 
     
     
         15 . The battery cell of  claim 1 , wherein, the cathode is a metal sulfide based cathode. 
     
     
         16 . The battery cell of  claim 15 , wherein the cell is a secondary cell and the metal sulfide based cathode is selected from the group consisting of FeS 2  and TiS 2 . 
     
     
         17 . The battery cell of  claim 15 , wherein the cell is a primary cell and the unlithiated metal sulfide based cathode is selected from the group consisting of FeS and CuS. 
     
     
         18 . The battery cell of  claim 1 , wherein the cathode is an active sulfur cathode. 
     
     
         19 . The battery cell of  claim 18 , wherein the active sulfur cathode is selected from the group consisting of elemental sulfur, polysulfides and combinations thereof. 
     
     
         20 . The battery cell of  claim 1 , wherein the cathode is a PEO/carbon/metal-oxide type cathode.