Thin film buried anode battery

Abstract

A reverse configuration, lithium thin film battery ( 300 ) having a buried lithium anode layer ( 305 ) and process for making the same. The present invention is formed from a precursor composite structure ( 200 ) made by depositing electrolyte layer ( 204 ) onto substrate ( 201 ), followed by sequential depositions of cathode layer ( 203 ) and current collector ( 202 ) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer ( 305 ) is formed via electroplating a lithium anode layer at the interface of substrate ( 201 ) and electrolyte film ( 204 ). The electroplating is accomplished by applying a current between anode current collector ( 201 ) and cathode current collector ( 202 ).

1 - 17 . (canceled) 
     
     
         18 . A lithium thin film secondary battery comprising:
 a) an anode current collector layer that has at least one conductive face and is characterized by its ability to function as a substrate   b) a buried anode layer comprising lithium metal in communication with a conductive face of said anode current collector;   c) an electrolyte layer, one face of which is in communication with said anode layer;   d) a cathode layer that is in communication with a face of said electrolyte layer that is not in communication with said anode layer; and   e) a cathode current collector layer that is in communication with a face of the cathode layer that is not in communication with the electrolyte layer, the battery being characterized by an increase in the amount of metallic lithium contained in its buried anode layer upon charging and a reduction in the amount of lithium metal in its buried anode layer upon discharging, and its chemical stability when exposed to an ambient environment in any state of charge.   
     
     
         19 . The battery of  claim 18  having an anode current collector comprising a stainless steel, an electrolyte comprising sub-stoichiometric lithium phosphorous oxynitride, and a cathode layer comprising a material of the formula LixV205, where in the uncharged state, x is about 3 or greater. 
     
     
         20 - 40 . (canceled)