DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of Application
Claims 1-2,4-9,11 are currently pending. Claims 3 and 10 are canceled. Claim 1 is currently amended.
Response to Arguments
Applicant’s arguments with respect to amended claim(s) 1 have been considered but are not found persuasive because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-2, 4-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song (WO2019078544A1, US20210083273A1 was used for citation; previously cited), in view of Jeong (US20160013481A1, previously cited) and Kim (US20200243848A1, IDS cited 11/18/2021).
Regarding claims 1,2, 4-5 Song discloses a negative electrode for a rechargeable lithium battery (Example 1; [0060-0062]; title), comprising:
a current collector (copper current collector [0062]);
a first negative active material layer [0060] on one side of the current collector and comprising a first negative active material (i.e., silicon oxide [0060]) and a first conductive material (i.e., carbon black [0060])
a second negative active material layer [0061] on one side of the first negative active material layer and comprising a second negative active material (i.e., artificial graphite [0061]) and a second conductive material (i.e., carbon black [0061]),
In Example 1, Song discloses wherein the first negative active material is a silicon oxide [0060] which is not a Si-carbon composite, as claimed.
However, Song further discloses that the first negative electrode active material may comprise one or more selected from the group consisting of Si, particles of silicon oxide, a Si-metal alloy, and a Si-carbon composite [0028]. Thus, it would have been obvious for a person having ordinary skill in the art before the effective filing date to have used a Si-carbon composite as an alternative to the silicon oxide of Example 1, as Song further discloses that such silicon-based material exhibits a high capacity [0028].
As modified above, Song discloses the use of Si-carbon composite as the first negative electrode, but Song does not explicitly disclose the structure of the Si-carbon composite.
In this regard, Jeong teaches an anode active material for a lithium secondary battery (title), wherein the anode active material comprises a core layer 10 (Fig 1) comprising a carbon-silicon composite (“silicon particles dispersed in a carbonaceous material” [0035-0037]) and a shell layer 20 comprising a conductive material 21 and a carbonaceous material 22 [0035, 0048-0051] for an anode active material that exhibits high capacity silicon properties while also improving the life characteristics of a secondary battery by mitigating the volume expansion problem during charge and discharge [Jeong 0037].
Thus, it would have been obvious for a person having ordinary skill in the art to have modified the Si-carbon composite of Song, such that it comprises a core comprising a mixture of Si particles and a second carbon-based material, and a third carbon-based material around the core, as claimed, with a reasonable expectation to provide an anode having high capacity and improved life characteristics of a secondary battery ([0037 Jeong]).
In Example 1, Song further discloses wherein the first and second conductive materials are both carbon black, wherein the conductive material is are not particularly limited as long as it has electrical conductivity without causing a chemical change in a battery, and may be selected from the list comprising a linear conductive material such as conductive fiber (e.g., carbon fiber, metal fiber, or the like), graphite, carbon black [0041].
Thus, while Song discloses wherein the second negative active material layer comprises a second negative active material layer (i.e., artificial graphite [0061] – {for claim 5}) with the particle-shaped conductive material (i.e., carbon black [0061] – {for claim 4}), Song does not explicitly disclose wherein:
the first negative active material layer comprises a linear conductive material with the Si-C composite, wherein the first negative active material layer further does not comprise any particle shaped conductive material, as required by the instant claim 1.
In this regard, Kim is also directed to a negative electrode comprising a first and a second negative electrode active material layers comprising conductive materials (abstract). Kim further teaches that carbon black conductive material (i.e., particle-shaped conductive material) forms a stable spot contact mode and is highly effective for carbonaceous active materials that experience little volume change [0036 Kim], and further teaches that the linear carbon nanotubes should be used for Si-based materials that undergo massive volume expansion and cracking, as the fibrous phase of the carbon nanotubes can cover and crosslink the cracked silicon-based particles, thereby maintaining the conductive pathway [0040-0041 Kim].
Thus, it would have been obvious for a person having ordinary skill in the art before the effective filing date to have structured the negative electrode of Song such that:
the first negative active material layer comprising the Si-C composite includes a linear conductive material (e.g., carbon nanotubes [0040-0041 Kim] – {for claim 2}) to cover and crosslink the silicon-based materials, thereby maintaining the conductive pathway and improve cycle characteristics [0040-0041 Kim], and
the second negative active material layer comprising the artificial graphite as the second negative active material to further include a particle shaped conductive material to provide a stable contact mode [0036 Kim].
Song further discloses wherein the second negative active material layer is spaced apart from the current collector with the first negative active material layer therebetween [0062].
Regarding claim 6, modified Song discloses the negative electrode claim 5, wherein the first negative active material further comprises natural graphite [Song 0060] which is a form of crystalline carbon.
Regarding claim 7, modified Song discloses the negative electrode of claim 1, wherein thicknesses of the first and the second negative active material layer are 100 μm and 10 μm, respectively [Song 0062]. Thus, the thickness of the second negative active material layer about 9% of a total thickness of the first and the second negative active material layer (i.e., 10/110), which falls within the claimed range of “about 1% to about 75% of a total thickness of the first negative active material layer and the second negative active material layer”.
Regarding claim 8, modified Song discloses a rechargeable lithium battery comprising the negative electrode of claim 1 ([0090]; modified in claim 1 rejection), a positive electrode [0090], and an electrolyte [0090].
Regarding claim 9, modified Song discloses the negative electrode of claim 1, comprising Si-carbon composite, as modified by Jeong. Jeong further teaches wherein the Si-carbon composite comprises the Si-particles and a first carbon-based material (i.e., Si particles and pitch [0098, 0100] – Jeong).
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song (WO2019078544A1, US20210083273A1 was used for citation; previously cited), in view of Jeong (US20160013481A1, previously cited), Kim (US20200243848A1, IDS cited 11/18/2021), and d Ko (US20190123356A1, previously cited).
Regarding claim 11, modified Song discloses the negative electrode of claim 1, comprising the linear conductive material, as modified by Kim. Kim further teaches wherein the carbon nanotubes have an average diameter of 10-120nm to retain conductivity and improve cycle characteristics of a lithium secondary battery [Kim 0045-0046], wherein the disclosed diameter range significantly overlaps with the claimed range of “about 10 nm to about 40nm”. Thus, it would have been obvious for a person having ordinary skill in the art before the effective filing date to have selected the overlapping diameter range with a reasonable expectation to provide conductivity and to improve cycle characteristics [Kim 0045-0046]. Kim further discloses wherein the carbon nanotubes may have a length of 0.5-20μm [Kim 0046], wherein the length range does not fall within the claimed range of “about 30µm to about 100 µm”. Examiner notes that the size of an article is not a matter of invention. See In re Rose, 105 USPQ 237 (CCPA 1955) (see MPEP § 2144.04). Further, Ko also teaches an active material layer comprising carbon nanotubes, wherein the carbon nanotubes have an average length of greater than or equal to about 40µm to about 250 µm to reduce resistance of the electrode while improving high rate charge/discharge performance and cycle life of the battery [0021 Ko]. Thus, it would have been obvious for a person having ordinary skill in the art to have modified the length of the carbon nanotube of Kim, such that it is in the overlapping range taught by Ko, with a reasonable expectation to reduce resistance, improve high rate charge/discharge performance and cycle life of the battery [0021 Ko].
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/T.S./Examiner, Art Unit 1751
/Haroon S. Sheikh/Primary Examiner, Art Unit 1751
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