Plasma enhanced chemical vapor deposition vanadium oxide thin films

Abstract

Thin-film vanadium oxide layer that is suitable for use as a cathode in a lithium ion battery or other electronic applications, such as ion insertion layers in electrochromic devices as well as other uses, is deposited by a plasma-enhanced chemical vapor deposition at room temperature at rates as high as 11 Å/sec. from a vanadium-containing precursor reacted with oxygen and hydrogen. The vanadium oxide-based cathode produced by a lower temperature process and at a high deposition rate, exhibits a high discharge capacity, a high energy density, and a negligible capacity fade fiom its second cycle to at least 2,900 cycles, thus providing enhanced cyclic stability and an improved component for rechargeable lithium-ion batteries and other electronic devices.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A thin-film vanadium oxide layer created through a plasma-enhanced chemical vapor deposition at room temperature and at a rate greater than 4.5 Å/sec. from a vanadium-containing precursor reacted with oxygen and hydrogen to disassociate vanadium atoms from other atoms in the precursor, to bond the vanadium atoms to the oxygen to form the vanadium oxide layer, and to bond the other atoms to the hydrogen in gaseous form and thereby result in the vanadium oxide layer being substantially free of such other atoms.  
     
     
         2 . The thin-film vanadium oxide layer of  claim 1 , wherein said thin-film vanadium oxide layer is V x O y  with X in a range of 1 to 6 and Y in a range of 1 to 13.  
     
     
         3 . The thin-film vanadium oxide layer of  claim 2 , wherein V x O y  includes at least one of VO 2 , V 2 O 5 , and V 6 O 13 .  
     
     
         4 . The thin-film vanadium oxide layer of  claim 2 , wherein said thin-film vanadium oxide layer has a discharge capacity of at least 225 mAh/g.  
     
     
         5 . The thin-film vanadium oxide layer of  claim 2 , wherein said thin-film vanadium oxide layer has an energy density of at least 2,977 Wh/l.  
     
     
         6 . The thin-film vanadium oxide layer of  claim 2 , wherein said thin-film vanadium oxide layer has negligible capacity fade from its second cycle to at least 2,900 cycles.  
     
     
         7 . The thin-film vanadium oxide layer of  claim 2 , wherein said thin-film vanadium oxide layer is created at a deposition rate of at least about 11 Å/s.