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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 1/26/2026 has been entered.
Response to Amendment
This Office Action is responsive to the amendment filed on 9/19/2025. Claims 5 and 17 are canceled. Claims 1-4, 6-10, 12-16, 18-20 are pending. Applicant’s arguments have been considered. Claims 1-4, 6-10, 12-16, 18-20 are non-finally rejected for reasons stated herein below.
Claim Rejections - 35 USC § 102/103
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-4, 6-10, 12-16, 18-20 are rejected under 35 U.S.C. 102(a1) as being anticipated by Kizaki (US 2018/0309160), or in alternative, rejected under 35 U.S.C. 103 as being unpatentable over Kizaki (US 2018/0309160).
Regarding claims 1, 12, 13, Kizaki discloses a negative electrode material, comprising: a silicon-based material. Regarding “wherein for a test cell comprising an electrode containing the negative electrode material and a counter electrode made of lithium metal, first-cycle efficiency of the test cell is 81% to 86%, and a discharge capacity at an electric potential of the electrode in the test cell being 0.17V accounts for 35% to 65% of a first-cycle discharge capacity of the test cell”, it is noted that the first-cycle efficiency and the first-cycle discharge capacity of Applicant’s limitation is for a “test cell” that contains the silicon-based material as claimed. This is an electrochemical property of the silicon-based material.
The instant Specification states:
[0072] It can be learned from comparison between Examples 1 to 5 that when a discharge capacity of a test cell when an electric potential of a negative electrode made of a silicon-based material is 0.17V accounts for a larger percentage of a first-cycle discharge capacity of the test cell, the silicon-based material has better normal-temperature and high-temperature cycling performance in an electrochemical apparatus (full cell). and an electrode assembly has a lower swelling rate. This is because a larger capacity percentage indicates that an active material has characteristics closer to those of an amorphous silicon-based material. To be specific, a silicon compound with a smaller disproportionation is subject to less swelling and shrinkage during charge and discharge, thereby effectively improving cycling performance and decreasing swelling rate of corresponding electrochemical apparatuses. In addition, such capacity percentage has an upper limit value of 65% due to characteristics of the silicon-based material.
Kizaki discloses that when a mixed powder of a silicon oxide powder and a lithium compound powder are rapidly heated, lithium silicate in which the proportion of Li to Si is high, that is, Li4SiO4, which is generated by a sudden reaction with Li is formed in the vicinity of the surface of particles constituting the silicon oxide powder (hereunder, also referred to as “silicon oxide particles”). The average composition of the silicon oxide powder is, for example, SiOx (0.5<x<1.5), and at the time when Li4SiO4 is formed a large amount of O is consumed in comparison to Si. As a result, in the silicon oxide, surplus Si that does not bind with O occurs as crystalline Si. Since crystalline Si is stable, once crystalline Si is formed, it is difficult for the crystalline Si to return to Si that constitutes amorphous silicon oxide [0029].
Further, when the surface of the silicon oxide particles is covered with Li4SiO4, it is difficult for Li to diffuse into the interior of the silicon oxide particles. Therefore, concentration of Li in the vicinity of the surface of the silicon oxide particles is promoted. As a result, the amount of crystalline Si increases during calcination [0030].
Therefore, as a measure for obtaining an Li-doped silicon oxide powder that contains Li and contains a low proportion of crystalline Si (or does not substantially contain crystalline Si), it is conceivable to suppress the formation of Li.sub.4SiO.sub.4 when producing the powder [0031].
In this powder, P2/P1≤1.0, and hence the proportion of crystalline Si to the amount of Li2SiO3 is small. Therefore, the capacity retention rate over a long-term cycle (for example, 500 cycles) of a battery in which the powder is used for a negative electrode is high. To obtain this effect, it is preferable that P2/P1≤0.5, and more preferably that P2/P1≤0.1 [0041].
In this powder, P3/P1≤1.0, and hence the proportion of Li.sub.2SiO.sub.4 to the amount of Li2SiO3 is small. As described later, by producing this powder under conditions such that P3/P1≤1.0, the content ratio of crystalline Si can be made small [0042].
The Examiner notes that the near-zero crystallinity of Kizaki appears to meet Applicant’s limitation of “a discharge capacity at an electric potential of the electrode in the test cell being 0.17V accounts for 35% to 65% of a first-cycle discharge capacity of the test cell” “wherein for a test cell comprising an electrode containing the negative electrode material and a counter electrode made of lithium metal.”
Regarding the limitation in claims 1, 12, 13, “first-cycle efficiency of the test cell is 81% to 86%”, it is defined that initial efficiency is the ratio of the initial discharge capacity to the initial charge capacity ([0006] of Kizaki), which naturally implies that a higher initial discharge capacity would meet a higher initial efficiency. Further, Kizaki discloses a powder can be produced in which formation of crystalline Si is suppressed, and when used for a negative electrode of a lithium ion secondary battery, the powder can increase the initial efficiency as well as the capacity retention rate over a long-term cycle [0024]. Hence, the instant Specification states that an amorphous nature of the silicon-based active material accounts for a larger percentage of a first-cycle discharge capacity [0072]. The instant Table 1 shows that a discharge capacity percentage at 0.17V of 65% shows a first-cycle efficiency of 83.2%. Hence, it appears that the near-zero nature of Kizaki’s active material would meet Applicant’s limitation.
Further, the instant Tables 1 and 2 show that Example 3 through Example 5 that meets Applicant’s “a discharge capacity at an electric potential of the electrode in the test cell being 0.17V accounts for 35% to 65% of a first-cycle discharge capacity of the test cell” show a lower swelling rate.” Kizaki discloses it is known in the art that crystals of Si (hereunder, referred to as “crystalline Si”) precipitate within the silicon oxide. The crystalline Si expands and contracts intensely during charging of the relevant lithium ion secondary battery. In accompaniment therewith, the working electrode is liable to detach from the working electrode current collector and therefore electrical conduction is liable to be lost between particles constituting the working electrode. Consequently, the capacity retention rate (ratio of the charge capacity after repeating charging/discharging with respect to the initial charge capacity) over a long-term cycle of the lithium ion secondary battery decreases [0010].
According to the production method of the present invention, a powder can be produced in which formation of crystalline Si is suppressed, and when used for a negative electrode of a lithium ion secondary battery, the powder can increase the initial efficiency as well as the capacity retention rate over a long-term cycle [0024].
Therefore, as a measure for obtaining an Li-doped silicon oxide powder that contains Li and contains a low proportion of crystalline Si (or does not substantially contain crystalline Si), it is conceivable to suppress the formation of Li4SiO4 when producing the powder [0031].
It appears that the amorphous silicon-based active material of Kizaku would also yield low swelling rate, and hence would meet Applicant’s “a discharge capacity at an electric potential of the electrode in the test cell being 0.17V accounts for 35% to 65% of a first-cycle discharge capacity of the test cell” show a lower swelling rate.”
MPEP 2112 V states that "once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the Examiner presents evidence or reasoning tending to show inherency, the burden shifts to the Applicant to show an unobvious difference."
Regarding claim 2, 14, a charge capacity at the electric potential of the electrode in the test cell being 0.4V accounts for 35% to 65% of a first-cycle charge capacity of the test cell, and regarding claim 10, a charge capacity at the electric potential of the electrode in the test cell being 0.4V accounts for 50% to 80% of a first-cycle charge capacity of the test cell, it is noted that a charge capacity of Applicant’s limitation is for a “test cell” that contains the silicon-based material as claimed. This is an electrochemical property of the silicon-based material.
The instant Specification states:
[0026] In some embodiments. a charge capacity at the electric potential of the electrode in the test cell being 0.4V accounts for 35% to 65% of a first-cycle charge capacity of the test cell. In some embodiments. lithium-doping modification conditions of silicon compound can be adjusted to satisfy the foregoing range of the charge capacity. If a charge capacity when an electric potential of a silicon-based negative electrode in a test cell is O.4V accounts for a smaller percentage of a first-cycle charge capacity of the test cell. the silicon-based material has better normal-temperature and high-temperature cycling performance in a full cell. and an electrode assembly has a lower swelling rate. This is because a smaller capacity percentage indicates that a silicon-based active material has characteristics closer to those of an amorphous silicon-based material. To be specific, a silicon compound with a smaller disproportionation leads to less swelling and shrinkage of the silicon-based material during charge and discharge, thereby effectively improving cycling performance and decreasing swelling rate of electrochemical apparatuses. In addition. such capacity percentage has a lower limit value of 35% due to characteristics of the silicon-based material.
It is noted that the amorphous silicon-based active material of Kizaku would also meet Applicant’s charge capacity of the electrode in the test cell as claimed.
Regarding claim 4, the silicon-based material comprises MySiOx, wherein 0≤y≤4, 0≤x≤4, and M comprises at least one of Li, Mg, Ti, or Al [0027].
Regarding claim 6, a median particle size of the silicon-based material is 0.5 μm to 20 μm [0036].
Regarding claim 7, a specific surface area of the silicon-based material is 1 m2/g to 30 m2/g [0037].
Regarding claim 8, a specific surface area of the silicon-based material is m2/g to 10 m2/g [0037].
Regarding claim 9, a median particle size of the silicon-based material is 5 μm to 10 μm [0036].
Regarding claim 1, 12, 13, the first-cycle discharge capacity of the test cell is in a range of 1800 mAh/g to 2400 mAh/g, and regarding claim 3, 15, the first-cycle discharge capacity of the test cell is in a range of 2000 mAh/g to 2400 mAh/g, it is noted that first-cycle discharge capacity of Applicant’s limitation is for a “test cell” that contains the silicon-based material as claimed. This is an electrochemical property of the silicon-based material. Applicant’s test cell comprises an electrode containing the negative electrode material and a lithium counter electrode [0024]. Kizaki discloses an initial discharge capacity between 1650 mAh/g to 1720 mAh/g, for a full battery having a negative electrode comprising an active material, binder and a conductive material, a cathode comprising an active material, binder and a conductive material, and a non-aqueous electrolyte [0069-0070]. Kizaki discloses lithium is doped to the silicon oxide particle to improve initial efficiency [0007-0009].
It appears from Applicant’s Table 1 that the claimed limitation would be met by a high or low discharge capacity percentage, which would be met by Kizaki’s near-zero crystalline active material. See instant Specification [0072].
Further, the instant Specification states
In some embodiments, the first-cycle discharge capacity of the test cell is in a range of 2000mAh/g to 2400mAh/g. In some embodiments. any appropriate method such as adjusting lithium-doping modification conditions of silicon compound can be performed to satisfy the foregoing range of the charge capacity. A higher first-cycle discharge capacity of the test cell indicates less lithium doped on a surface, and hence lower first-cycle efficiency and higher swelling rate. A lower first-cycle discharge capacity of the test cell indicates more lithium doped on a surface, and hence higher first-cycle efficiency and a lower swelling rate. An excessively low first-cycle discharge capacity of the test cell indicates excessive doping lithium. which results in gelation of a slurry, thereby degrading cycling perfomance of the negative electrode material. When the first-cycle discharge capacity of the test cell is excessively high, too little doping lithium and excessively low first-cycle efficiency result in poorer cycling performance. Therefore, the first-cycle discharge capacity of the test cell is set in the range of 2000mAh/g to 2400 mAh/g [0027].
Kizaki discloses in the first preliminary calcination step, the first mixed powder that is obtained by mixing the silicon oxide powder and the lithium compound powder is calcined at a preliminary calcination temperature that is 30 to 200° C. lower than the decomposition temperature of the relevant lithium compound powder. At the preliminary calcination temperature, the lithium compound gradually decomposes, and the Li constituting the lithium compound and the silicon oxide powder gradually react. Consequently, Li is not concentrated on the surface of the silicon oxide particles and it is easy to cause the Li to diffuse as far as the interior of the silicon oxide powder. By this means, formation of Li.sub.4SiO.sub.4 is suppressed, and thus the formation of crystalline Si can be suppressed. When the decomposition temperature of the lithium compound is high (for example, 600° C. or more), in order to obtain the aforementioned effect it is preferable to make the preliminary calcination temperature lower by 50 to 200° C. than the decomposition temperature of the lithium compound [0048].
In the first main calcination step, Li is evenly diffused inside the silicon oxide particles [0049].
Preferably, the present production method further includes a second mixing step, a second preliminary calcination step and a second main calcination step. In the second mixing step, after the first main calcination step, a lithium compound powder is added to the first mixed powder and mixed to obtain a second mixed powder. In the second preliminary calcination step, the second mixed powder is calcined at the preliminary calcination temperature. In the second main calcination step, after the second preliminary calcination step, the second mixed powder is calcined at the main calcination temperature [0050].
In this case, the amount of Li that is to be ultimately doped into the silicon oxide powder is added by dividing the addition of the relevant Li amount between the first mixing step and the second mixing step. By this means, the degree of concentration of Li on the surface of the silicon oxide particles can be lowered, and formation of Li.sub.4SiO.sub.4 and crystalline Si can be further reduced [0051].
It appears that the low concentration of Li on surface of Kizaki meets the limitation of Applicant’s claims 3 and 15. Should it not be anticipatory, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to adjust the Li on the surface of silicon oxide particles for the benefit of preventing the formation of crystalline Si, while still having good initial efficiency.
Regarding claims 1, 12, 13, in a diffraction pattern of particles of the silicon-based material in an X-ray diffraction test, a first peak intensity in an angle range of 20.5° to 21.5° is I1, and a second peak intensity in an angle range of 28.0° to 29.0° is I2, wherein 0<I2/I1<1. The instant Specification states:
[0081] It can be learned from comparison between Examples 20 to 23 that as an I2/I1 value increases, cycling performance of an electrochemical apparatus decreases and a swelling rate of the electrochemical apparatus increases. The I2/I1 value reflects a degree of impact of disproportionation on a silicon-based material. A larger I2/I1 value indicates larger sizes of nano-silicon grains produced by disproportionation of SiO in the silicon-based material, causing a sharp increase in stress in a local area during lithiation, thereby resulting in damage to a negative electrode material structure during cycling, and hence poorer cycling performance and increased swelling rate of the electrochemical apparatus. FIG. 4 is an X-ray diffraction pattern of particles of a silicon-based material in Example 20 of this disclosure.
It is noted that Applicant’s intensity ratio I2/I1 is a measure of the proportion of crystalline Si in the silicon-based material.
Kizaki discloses Li-doped silicon oxide powder that contains Li and contains a low proportion of crystalline Si (or does not substantially contain crystalline Si) that is conceivable to suppress the formation of Li4SiO4 when producing the powder [0031]. In this powder, P2/P1≤1.0, and hence the proportion of crystalline Si to the amount of Li2SiO3 is small. Therefore, the capacity retention rate over a long-term cycle (for example, 500 cycles) of a battery in which the powder is used for a negative electrode is high. To obtain this effect, it is preferable that P2/P1≤0.5, and more preferably that P2/P1≤0.1 [0041]. For example, Examples 1 through 4 disclose P2/P1 values of 0.73, 0, 0.5, 0, as shown in Table 1, in which P2 represents a peak attributed to crystalline Si and P1 represents a peak attributed to Li2SiO3 [0017]. It is noted that the P2/P3 value of zero indicates zero crystalline Si present in the silicon oxide powder of Kizaki. It appears that the low proportion of crystalline Si of Kizaki appears to meet Applicant’s limitation of the peak intensity ratio.
Should it not be anticipatory, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to minimize the amount of crystalline Si in Kizaki’s silicon oxide powder for the benefit of having good capacity characteristics and cycle characteristics of the battery.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Kizaki (US 2018/0309160) as applied to claim 12, in view of Lu (CN 104852019).
Regarding claim 21, the negative electrode plate comprises an active material layer and the active material layer comprises the silicon-based material, a carbon material, a conductive agent, and a binder;
a mass ratio of the silicon-based material to the conductive agent to the binder is (5—96):(0.5—10):(0.5—10); and
surfaces of particles of the silicon-based material contains a carbon coating [0043].
Kizaki does not disclose a carbon material and its mass ratio. Lu teaches a silicon metal composite anode material has a novel silicon metal alloy-based composite structure, in which active nano-silicon metal alloy material is dispersed in an oxide that serves as a buffer substrate, and the conductivity and rate performance of the material are improved by adding graphite [0012].
The composite negative electrode material can be used directly alone in lithium-ion batteries, or it can be mixed with other lithium storage materials in a ratio of 1wt% to 99wt%, and the other lithium storage materials are graphite, Sn alloy or transition metal oxides, preferably one or more of graphite, transition metals and their oxides [0013].
The silicon metal composite anode material of the present invention has a stable structure. The oxide and carbon materials, which serve as the material buffer framework, can effectively buffer the stress caused by the volume change of the silicon metal alloy during charging and discharging, so that the composite material has good electrochemical stability [0024].
It would have been obvious to one of ordinary skilled in the art at the time the invention was made to add metal oxide or graphite, or both, to the silicon anode active material of Kizaki, as taught by Lu, for the benefit of buffering the expansion of silicon during charge and discharge.
Response to Arguments
Arguments dated 1/6/2026 regarding Oh are moot in view of the new grounds of rejection.
Regarding claims 1, 12, 13, in a diffraction pattern of particles of the silicon-based material in an X-ray diffraction test, a first peak intensity in an angle range of 20.5° to 21.5° is I1, and a second peak intensity in an angle range of 28.0° to 29.0° is I2, wherein 0<I2/I1<1. The instant Specification states:
[0081] It can be learned from comparison between Examples 20 to 23 that as an I2/I1 value increases, cycling performance of an electrochemical apparatus decreases and a swelling rate of the electrochemical apparatus increases. The I2/I1 value reflects a degree of impact of disproportionation on a silicon-based material. A larger I2/I1 value indicates larger sizes of nano-silicon grains produced by disproportionation of SiO in the silicon-based material, causing a sharp increase in stress in a local area during lithiation, thereby resulting in damage to a negative electrode material structure during cycling, and hence poorer cycling performance and increased swelling rate of the electrochemical apparatus. FIG. 4 is an X-ray diffraction pattern of particles of a silicon-based material in Example 20 of this disclosure.
It is noted that Applicant’s intensity ratio I2/I1 is a measure of the proportion of crystalline Si in the silicon-based material.
Kizaki discloses Li-doped silicon oxide powder that contains Li and contains a low proportion of crystalline Si (or does not substantially contain crystalline Si) that is conceivable to suppress the formation of Li4SiO4 when producing the powder [0031]. In this powder, P2/P1≤1.0, and hence the proportion of crystalline Si to the amount of Li2SiO3 is small. Therefore, the capacity retention rate over a long-term cycle (for example, 500 cycles) of a battery in which the powder is used for a negative electrode is high. To obtain this effect, it is preferable that P2/P1≤0.5, and more preferably that P2/P1≤0.1 [0041]. For example, Examples 1 through 4 disclose P2/P1 values of 0.73, 0, 0.5, 0, as shown in Table 1, in which P2 represents a peak attributed to crystalline Si and P1 represents a peak attributed to Li2SiO3 [0017]. It is noted that the P2/P3 value of zero indicates zero crystalline Si present in the silicon oxide powder of Kizaki. It appears that the low proportion of crystalline Si of Kizaki appears to meet Applicant’s limitation of the peak intensity ratio.
Should it not be anticipatory, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to minimize the amount of crystalline Si in Kizaki’s silicon oxide powder for the benefit of having good capacity characteristics and cycle characteristics of the battery.
Regarding claims 1, 12, 13, “wherein for a test cell comprising an electrode containing the negative electrode material and a counter electrode made of lithium metal, first-cycle efficiency of the test cell is 81% to 86%, and a discharge capacity at an electric potential of the electrode in the test cell being 0.17V accounts for 35% to 65% of a first-cycle discharge capacity of the test cell”, it is noted that the first-cycle efficiency and the first-cycle discharge capacity of Applicant’s limitation is for a “test cell” that contains the silicon-based material as claimed. This is an electrochemical property of the silicon-based material.
The instant Specification states:
[0072] It can be learned from comparison between Examples 1 to 5 that when a discharge capacity of a test cell when an electric potential of a negative electrode made of a silicon-based material is 0.17V accounts for a larger percentage of a first-cycle discharge capacity of the test cell, the silicon-based material has better normal-temperature and high-temperature cycling performance in an electrochemical apparatus (full cell). and an electrode assembly has a lower swelling rate. This is because a larger capacity percentage indicates that an active material has characteristics closer to those of an amorphous silicon-based material. To be specific, a silicon compound with a smaller disproportionation is subject to less swelling and shrinkage during charge and discharge, thereby effectively improving cycling performance and decreasing swelling rate of corresponding electrochemical apparatuses. In addition, such capacity percentage has an upper limit value of 65% due to characteristics of the silicon-based material.
Kizaki discloses that when a mixed powder of a silicon oxide powder and a lithium compound powder are rapidly heated, lithium silicate in which the proportion of Li to Si is high, that is, Li.sub.4SiO.sub.4, which is generated by a sudden reaction with Li is formed in the vicinity of the surface of particles constituting the silicon oxide powder (hereunder, also referred to as “silicon oxide particles”). The average composition of the silicon oxide powder is, for example, SiOx (0.5<x<1.5), and at the time when Li4SiO4 is formed a large amount of O is consumed in comparison to Si. As a result, in the silicon oxide, surplus Si that does not bind with O occurs as crystalline Si. Since crystalline Si is stable, once crystalline Si is formed, it is difficult for the crystalline Si to return to Si that constitutes amorphous silicon oxide [0029].
Further, when the surface of the silicon oxide particles is covered with Li4SiO4, it is difficult for Li to diffuse into the interior of the silicon oxide particles. Therefore, concentration of Li in the vicinity of the surface of the silicon oxide particles is promoted. As a result, the amount of crystalline Si increases during calcination [0030].
Therefore, as a measure for obtaining an Li-doped silicon oxide powder that contains Li and contains a low proportion of crystalline Si (or does not substantially contain crystalline Si), it is conceivable to suppress the formation of Li.sub.4SiO.sub.4 when producing the powder [0031].
In this powder, P2/P1≤1.0, and hence the proportion of crystalline Si to the amount of Li2SiO3 is small. Therefore, the capacity retention rate over a long-term cycle (for example, 500 cycles) of a battery in which the powder is used for a negative electrode is high. To obtain this effect, it is preferable that P2/P1≤0.5, and more preferably that P2/P1≤0.1 [0041].
In this powder, P3/P1≤1.0, and hence the proportion of Li.sub.2SiO.sub.4 to the amount of Li2SiO3 is small. As described later, by producing this powder under conditions such that P3/P1≤1.0, the content ratio of crystalline Si can be made small [0042].
The Examiner notes that the near-zero crystallinity of Kizaki appears to meet Applicant’s limitation of “a discharge capacity at an electric potential of the electrode in the test cell being 0.17V accounts for 35% to 65% of a first-cycle discharge capacity of the test cell” “wherein for a test cell comprising an electrode containing the negative electrode material and a counter electrode made of lithium metal.”
Regarding the limitation in claims 1, 12, 13, “first-cycle efficiency of the test cell is 81% to 86%”, it is defined that initial efficiency is the ratio of the initial discharge capacity to the initial charge capacity ([0006] of Kizaki), which naturally implies that a higher initial discharge capacity would meet a higher initial efficiency. Further, Kizaki discloses a powder can be produced in which formation of crystalline Si is suppressed, and when used for a negative electrode of a lithium ion secondary battery, the powder can increase the initial efficiency as well as the capacity retention rate over a long-term cycle [0024]. Hence, the instant Specification states that an amorphous nature of the silicon-based active material accounts for a larger percentage of a first-cycle discharge capacity [0072]. The instant Table 1 shows that a discharge capacity percentage at 0.17V of 65% shows a first-cycle efficiency of 83.2%. Hence, it appears that the near-zero nature of Kizaki’s active material would meet Applicant’s limitation.
Further, the instant Tables 1 and 2 show that Example 3 through Example 5 that meets Applicant’s “a discharge capacity at an electric potential of the electrode in the test cell being 0.17V accounts for 35% to 65% of a first-cycle discharge capacity of the test cell” show a lower swelling rate.” Kizaki discloses it is known in the art that crystals of Si (hereunder, referred to as “crystalline Si”) precipitate within the silicon oxide. The crystalline Si expands and contracts intensely during charging of the relevant lithium ion secondary battery. In accompaniment therewith, the working electrode is liable to detach from the working electrode current collector and therefore electrical conduction is liable to be lost between particles constituting the working electrode. Consequently, the capacity retention rate (ratio of the charge capacity after repeating charging/discharging with respect to the initial charge capacity) over a long-term cycle of the lithium ion secondary battery decreases [0010].
According to the production method of the present invention, a powder can be produced in which formation of crystalline Si is suppressed, and when used for a negative electrode of a lithium ion secondary battery, the powder can increase the initial efficiency as well as the capacity retention rate over a long-term cycle [0024].
Therefore, as a measure for obtaining an Li-doped silicon oxide powder that contains Li and contains a low proportion of crystalline Si (or does not substantially contain crystalline Si), it is conceivable to suppress the formation of Li4SiO4 when producing the powder [0031].
It appears that the amorphous silicon-based active material of Kizaku would also yield low swelling rate, and hence would meet Applicant’s “a discharge capacity at an electric potential of the electrode in the test cell being 0.17V accounts for 35% to 65% of a first-cycle discharge capacity of the test cell” show a lower swelling rate.”
MPEP 2112 V states that "once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the Examiner presents evidence or reasoning tending to show inherency, the burden shifts to the Applicant to show an unobvious difference."
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to whose telephone number is (571)272-8699. The examiner can normally be reached on M-F until 5pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Leong can be reached at 571-270-1292. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CYNTHIA K WALLS/ Primary Examiner, Art Unit 1751
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