Appeal 2007-1118
Application 10/237,089
SiOx (x=1.05-1.60), i.e., the material is ultimately selected to alloy with, or
absorb, lithium ions (Answer 7).
Second, there are several bases for one of ordinary skill in the art to
have been led to combine the coating of Umeno with the particles of
Sakashita that arise from benefits taught by Umeno any one of which would
have been sufficient to support the prima facie case of obviousness. Umeno
articulates several benefits to using a carbon coating that one of ordinary
skill in the art would have expected to obtain when the coating were placed
on Sakashita’s SiOx (x=1.05-160) particles including suppression of
expansion during lithium ion alloying, prevention of further oxidation during
charging and discharging, and improvement in conductivity. Umeno’s
disclosure of conductivity improvement provides a strong reason to combine
because Sakashita expressly teaches that conductivity improvement is
desirable as noted in the above findings of fact. Thus, an ordinarily skilled
artisan would have expected that Umeno’s carbon coating would be suitable
as an additive source of conductive carbon or as a substitution of a carbon
source for use in Sakashita’s conductive electrode. Another reason for
making the combination arises from the expected added benefit of
suppressing any expansion that might occur when Sakashita’s SiOx (x=1.05-
160) particles, or the Si particles therein, absorb lithium ions. Umeno
teaches that the expansion inhibiting carbon coating will prevent the
powderization and destruction of the anode and improve cycle properties
(Factual findings above).
With regard to the benefit of suppressing expansion, it is reasonable to
conclude that because the SiOx of Sakashita stores lithium ions, one of
7
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