Protective layers for electrochemical cells

Abstract

Articles and methods including layers for protection of electrodes in electrochemical cells are provided. As described herein, a layer, such as a protective layer for an electrode, may comprise a plurality of particles (e.g., crystalline inorganic particles, amorphous inorganic particles). In some embodiments, at least a portion of the plurality of particles (e.g., inorganic particles) are fused to one another. For instance, in some embodiments, the layer may be formed by aerosol deposition or another suitable process that involves subjecting the particles to a relatively high velocity such that fusion of particles occurs during deposition. In some embodiments, the layer (e.g., the layer comprising a plurality of particles) is an ion-conducting layer.

What is claimed is: 
     
         1 . (canceled) 
     
     
         2 . An article for use in an electrochemical cell, comprising:
 a first layer;   a second layer disposed on the first layer comprising a plurality of particles having an original surface and comprising a first material, wherein at least a portion of the plurality of particles are fused to one another such that at least a portion of the original surface of the particles can no longer be discerned in the plurality of particles fused to one another; and   a second material present in the second layer,   wherein the first material comprises an ionically conductive material, and   wherein the second layer has an ionic conductivity between 10 −6  S/cm and 10 −1  S/cm.   
     
     
         3 . The article of  claim 1 , wherein the second material is ionically conductive. 
     
     
         4 . The article of  claim 1 , wherein the second material is non-ionically conductive. 
     
     
         5 . The article of  claim 1 , wherein at least 10 vol % of the second layer comprises one or more continuous pathways comprising an ionically conductive material. 
     
     
         6 . The article of  claim 1 , wherein the second layer has an ionic conductivity between 10 −5  S/cm and 10 −3  S/cm. 
     
     
         7 . The article of  claim 1 , wherein the second layer has an average thickness between 3 microns and 25 microns. 
     
     
         8 . The article of  claim 1 , wherein the plurality of particles have an average largest cross-sectional dimension of between 0.5 microns and 20 microns. 
     
     
         9 . The article of  claim 1 , wherein at least 50% of the plurality of particles are fused to one another. 
     
     
         10 . The article of  claim 1 , wherein the second layer comprises an ionically conductive material and a non-ionically conductive material. 
     
     
         11 . The article of  claim 1 , wherein the second layer comprises an ionically conductive material and a non-ionically conductive material, and wherein a weight ratio of the ionically conductive material to the non-ionically conductive material is at least 80:20. 
     
     
         12 . The article of any  claim 1 , wherein the first material comprises an inorganic material. 
     
     
         13 . The article of  claim 1 , wherein the first material comprises a ceramic material. 
     
     
         14 . The article of  claim 13 , wherein the ceramic material is a garnet. 
     
     
         15 . The article of  claim 1 , wherein the plurality of particles has a Young's elastic modulus of at least 1 GPa. 
     
     
         16 . The article of  claim 1 , wherein the second layer comprises an ionically conductive material and a non-ionically conductive material, and wherein the non-ionically conductive material has a Young's elastic modulus of at least 2 times smaller than the modulus of ionically conductive material. 
     
     
         17 . The article of  claim 1 , wherein the second layer has a density of between 1.5 and 6 g/cm 3 . 
     
     
         18 . The article of  claim 1 , wherein the second layer has a porosity of less than 5%. 
     
     
         19 . The article of  claim 1 , wherein the second material is present in at least a portion of spaces between the fused particles. 
     
     
         20 . The article of  claim 1 , wherein the second material is a polymeric material. 
     
     
         21 . An electrochemical cell comprising the article of  claim 1 .