Methods of making and inspecting a web of vitreous lithium sulfide separator sheet and lithium electrode assemblies

Abstract

A lithium ion-conductive solid electrolyte including a freestanding inorganic vitreous sheet of sulfide-based lithium ion conducting glass is capable of high performance in a lithium metal battery by providing a high degree of lithium ion conductivity while being highly resistant to the initiation and/or propagation of lithium dendrites. Such an electrolyte is also itself manufacturable, and readily adaptable for battery cell and cell component manufacture, in a cost-effective, scalable manner. An automated machine based system, apparatus and methods assessing and inspecting the quality of such vitreous solid electrolyte sheets, electrode sub-assemblies and lithium electrode assemblies can be based on spectrophotometry and can be performed inline with fabricating the sheet or web (e.g., inline with drawing of the vitreous Li ion conducting glass) and/or with the manufacturing of associated electrode sub-assemblies and lithium electrode assemblies and battery cells.

1 - 5 . (canceled) 
     
     
         6 . A method of inspecting a battery cell component, the method comprising:
 i) providing an electrode subassembly comprising:
 a dense solid inorganic electrolyte sheet as an ionically conductive separator layer having first and second opposing principal side surfaces; and 
 a material layer coated on the first principal side surface; and 
   ii) spectrophotometrically inspecting the electrode subassembly for defects or flaws at an interface between the dense solid inorganic electrolyte sheet and the material layer, wherein the spectrophotometric inspection is an automated inspection comprising:   providing a source of light of a specified wavelength, or the wavelength selectable from a range of wavelengths;   providing sensors for measuring intensity of the light;   providing a computer that interfaces with the sensors for collecting light intensity data;   shining the light at the solid electrolyte sheet for transmission or reflection measurements;   measuring the transmitted or reflected light intensity using said sensors; and   storing data from said sensors using said computer.   
     
     
         7 . The method of  claim 6 , wherein the material layer is reflective of light. 
     
     
         8 . The method of  claim 7 , wherein the material layer is a metal that is not lithium metal. 
     
     
         9 . The method of  claim 7 , wherein the spectrophotometric inspection is based on reflected light intensities at various wavelengths. 
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 6 , wherein the spectrophotometric inspection involves light attenuation. 
     
     
         12 . The method of  claim 11 , wherein the light is in the visible region. 
     
     
         13 . The method of  claim 6 , wherein the material layer is lithium metal. 
     
     
         14 . The method of  claim 6 , wherein the material layer is a lithium alloy. 
     
     
         15 . The method of  claim 11 , wherein the light attenuation is used to characterize and evaluate concentrations of any scattering centers in the bulk of the inorganic electrolyte sheet and at the interface between the inorganic electrolyte sheet and the material layer. 
     
     
         16 . The method of  claim 6 , wherein changes in reflectivity of the interface are monitored in order to identify areas of low Li reactivity at the interface. 
     
     
         17 . The method of  claim 6 , wherein the method involves monitoring reactions at the interface in real time. 
     
     
         18 . (canceled) 
     
     
         19 . The method of  claim 6 , wherein the spectrophotometric inspection is performed inline with the fabrication of subassembly. 
     
     
         20 . The method of  claim 19 , wherein the spectrophotometric inspection comprises spectrophotometrically inspecting the first and/or second principal side surface of the inorganic solid electrolyte sheet at a first glass sheet inspection station, and conveying the glass sheet to a second inspection station for inspecting the interface between the inorganic solid electrolyte sheet and the material layer on the first principal side surface of the inorganic solid electrolyte sheet. 
     
     
         21 - 30 . (canceled)