Ex Parte Fujita et al

Patent Trial and Appeal Board

Dec 1, 2014

12593795 (P.T.A.B. Dec. 1, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte HIDEAKI FUJITA and YUKIHIRO OKADA
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Appeal 2013-002411
Application 12/593,795
Technology Center 1700
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Before PETER F. KRATZ, BEVERLY A. FRANKLIN, and
ELIZABETH M. ROESEL, Administrative Patent Judges.

ROESEL, Administrative Patent Judge.

DECISION ON APPEAL

Appellants1 appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1, 2, and 5–8. We have jurisdiction under 35 U.S.C.
§ 6(b).
We REVERSE.

STATEMENT OF THE CASE
The claimed subject matter relates to a positive electrode for a non-
aqueous electrolyte secondary battery. App. Br. 15 (claim 1); Spec. ¶ 1.

1 According to Appellants, the Real Party in Interest is Panasonic
Corporation. App. Br. 1.
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Claim 1 is representative of the subject matter on appeal and is set forth
below (with bold added for emphasis):
1. A positive electrode for a non-aqueous electrolyte
secondary battery comprising:
an active material layer; and
a current collector carrying the active material layer
formed on at least one surface thereof, wherein:
the active material layer contains an active material
comprising a lithium composite metal oxide, 80% by weight or
more of a total amount of the lithium composite metal oxide
being in the form of primary particles of the lithium composite
metal oxide,
the primary particles of the lithium composite metal
oxide have a conductive coating layer formed on the surface
thereof,
conductive coating layer comprises at least one
conductive agent selected from the group consisting of
graphites, carbon blacks, and carbon fibers, and
the conductive coating layer is formed on the surface of
the primary particles of the lithium composite metal oxide by a
mechanochemical method in which the primary particles of the
active material and a conductive agent are dry-mixed.
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Choi et al. US 2003/0113627 A1 Jun. 19, 2003
Inagaki et al. US 2007/0009801 A1 Jan. 11, 2007
Hiroyasu et al. (Hiroyasu)2 JP 2001-143703 May 25, 2001

2 As translated.
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THE REJECTION
Claims 1, 2, and 5–8 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Hiroyasu in view of Choi and Inagaki. Ans. 3.

ANALYSIS
The Examiner finds that Hiroyasu discloses all elements of claim 1,
except for a conductive coating layer formed on the surface of the primary
particles. Ans. 3–4 (citing Hiroyasu, ¶¶ 1, 4, 8, 9, 12, 27–31).3 With respect
to that element, the Examiner finds that Choi teaches a cathode particle that
is coated with a conductive material. Id. at 4 (citing Choi, Fig. 2, ¶¶ 33, 44).
According to the Examiner, it would have been obvious to have coated the
particles of Hiroyasu with an additional coating of conductive material, as
taught by Choi. Id. (citing Choi, ¶¶ 15–17).
Appellants challenge the Examiner’s conclusion that it would have
been obvious to have combined the teachings of Hiroyasu and Choi. App.
Br. 4–8. Appellants argue that Choi teaches a conductive coating for a
sulfur-containing active material for a lithium sulfur battery, that the
problem addressed by Choi’s conductive coating is unique to lithium sulfur
batteries, and that, in view of Choi’s teachings, one of ordinary skill in the
art would not have been motivated to apply Choi’s conductive coating to
Hiroyasu’s active material particles. Id. at 7–8. After reviewing Appellants’
arguments, the Examiner’s Answer, and the cited references, we are
persuaded that Examiner’s articulated reasons for modifying and combining

3 The Examiner includes independent claim 7 in this determination and the
Examiner’s subsequent obviousness assessment without separately
addressing claim 7.
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the prior art teachings are not sufficient to support prima facie obviousness
under the facts of this case.
Under 35 U.S.C. § 103(a), the Examiner carries the initial burden of
establishing a prima facie case of obviousness. In re Piasecki, 745 F.2d
1468, 147172 (Fed. Cir. 1984). As part of meeting this initial burden, the
Examiner must determine whether the differences between the subject
matter of the claims and the prior art “are such that the subject matter as a
whole would have been obvious at the time the invention was made to a
person having ordinary skill in the art.” 35 U.S.C. § 103(a); Graham v. John
Deere Co., 383 U.S. 1, 13 (1966). To support the legal conclusion of
obviousness, “there must be some articulated reasoning with some rational
underpinning” for combining elements in the manner claimed. KSR Int’l Co.
v. Teleflex Inc., 550 U.S. 398, 418 (2007) (quoting In re Kahn, 441 F.3d
977, 988 (Fed. Cir. 2006)).
The Examiner articulates the following reasoning for combining the
teachings of Hiroyasu and Choi:
It would have been obvious to one of ordinary skill at the time
of the invention to coat the particle of Hiroyashu [sic, Hiroyasu]
with an additional shell coating of conductive material as taught
by Choi in order to reduce the amount of binder material
needed for the proportion of conductive material to active
material which can improve the cathodes of electrodes.
Ans. 4 (citing Choi, ¶¶ 15–17). The Examiner contends that the teachings of
Choi and Hiroyasu are combinable because both relate to lithium batteries,
that Choi’s teaching is not specific or exclusive to lithium sulfur batteries,
and that it would have been obvious to provide the conductive material
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disclosed by Hiroyasu in the form of a coating as taught by Choi for the
reasons set forth in Choi. Id. at ¶¶ 7–8 (citing Hiroyasu, ¶ 12; Choi, ¶ 13).
Based upon our review of the opposing arguments presented by
Appellants and the Examiner and the cited references, we are persuaded that
the Examiner’s articulated reasoning is not supported by the teachings of
Hiroyasu and Choi and that a preponderance of the evidence supports
Appellants’ position that one of ordinary skill in the art would not have been
motivated to apply a conductive coating as taught by Choi to particles of
active material as taught by Hiroyasu. A preponderance of the evidence
demonstrates that the Examiner’s rationale—that it would have been obvious
to have provided the conductive material in the form of a coating in order to
reduce the amount of binder material—applies to lithium sulfur batteries that
use sulfur-containing active material, but not to conventional lithium
batteries that use LiCoO2 as an active material, as taught by Hiroyasu. The
following teachings of Hiroyasu and Choi support this conclusion.
Hiroyasu discloses lithium metal oxide, LiCoO2, as a positive active
material for a lithium battery. Hiroyasu, Abstract, ¶ 9. According to
Hiroyasu, the positive active material is mixed with conductive agent and
binder to form a paste, which is applied a current collector to form an
electrode. Id., ¶ 12. Choi discloses a cathode (positive) electrode for a
lithium sulfur battery in which the amount of binder needed is reduced by
using a core-shell structure for the cathode material. Choi, Abstract, ¶¶ 17–
18. Choi distinguishes lithium sulfur batteries from conventional lithium
batteries that use LiCoO2 as the cathode (positive) active material. Id., ¶ 4–
6, 12–14. According to Choi, a large amount of conductive agent and binder
are needed for the cathode of lithium sulfur batteries, as compared with
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conventional lithium batteries. Id., ¶¶ 12–15. The large amount of
conductive agent and binder reduces the concentration of cathode active
material, which is an impediment to the manufacture of high-performance
cathode electrodes. Id., ¶ 15. According to Choi, this reduction in
concentration is not a problem for conventional lithium batteries, which
require only a minimum amount of conductive agent. Id. ¶ 13.
In view of the teachings of Choi distinguishing conventional lithium
batteries, such as the lithium batteries taught by Hiroyasu, we are persuaded
that one of ordinary skill in the art would not have been motivated to apply
Choi’s teaching regarding a core-shell structure for active material particles
to a conventional lithium battery, as that taught by Hiroyasu. We are further
persuaded that the rationale articulated by the Examiner—reducing the
amount of binder material needed for the proportion of conductive material
to active material—would not have motivated one of ordinary skill in the art
to modify the LiCoO2 active material particles taught by Hiroyasu to provide
the conductive material in the form of a coating. We therefore determine
that a preponderance of the evidence does not support the Examiner’s
conclusion of obviousness.

CONCLUSION OF LAW AND DECISION
Because the Examiner’s articulated reasoning for combining the
teachings of Hiroyasu and Choi lacks a rational underpinning and is not
supported by a preponderance of the evidence, we reverse the Examiner’s
decision rejecting claims 1, 2, and 5–8.

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REVERSED

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