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 .
Election/Restrictions
Applicant’s election without traverse of Group I (Claims 1-14) in the reply filed on 8/4/26 is acknowledged.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 7/27/26, 6/29/26, 3/30/26, 12/23/25, 8/28/25, and 4/9/24 were filed. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements have been considered by the examiner.
Drawings
The drawings were received on 4/9/2024. These drawings are acceptable.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 1, 6, 7, and 8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by CN 113707883 A (CN’883).
As to Claim 1:
CN’883 discloses a secondary battery, particularly a lithium-ion secondary battery subjected to repeated charging and discharging (CN’883, Pgs. 10-14); a negative electrode plate comprising a negative electrode material layer, wherein the negative electrode material layer includes graphite, silicon oxide, or silicon-carbon active material, a binder, and a conductive agent disposed on a copper-foil current collector (CN’883, Pgs. 8-9 and 11-14); a positive electrode plate comprising a positive electrode material layer, wherein the positive electrode material layer includes an organic-coating-covered positive electrode active material, a binder, and a conductive agent disposed on an aluminum-foil current collector (CN’883, Pgs. 8-9 and 11-13); and an electrolytic solution, particularly a commercial LiPF₆-system electrolyte employed in the assembled lithium-ion battery (CN’883, Pgs. 10-12 and 14).
CN’883 further discloses that the positive electrode material layer contains an interface passivator in the form of an organic coating containing ion-conductor compounds. The organic coating reduces direct contact between the positive electrode active material and the electrolyte, inhibits interfacial side reactions, protects the active material from corrosion, and improves interfacial stability and battery cycle performance (CN’883, Pgs. 2-5). CN’883 incorporates the organic coating into positive electrode active materials, including LiNi₀.₈Co₀.₁Mn₀.₁O₂, LiCoO₂, and LiFePO₄, and subsequently incorporates the coated active material into the positive electrode material layer (CN’883, Pgs. 8-9 and 11-13).
CN’883 also discloses that the interface-passivating coating contains compounds having an element E, including lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and lithium-containing LLZTO compounds. Examples 1-3 expressly incorporate LiTFSI and lithium-containing LLZTO into the organic coating provided on the positive electrode active material (CN’883, Pgs. 6-7 and 11-13). Accordingly, the element E is lithium, which is selected from the claimed group consisting of lithium, sodium, beryllium, magnesium, potassium, aluminum, gallium, and germanium.
As to Claim 6:
CN’883 discloses the secondary battery according to claim 1, as set forth in the rejection of claim 1 above. CN’883 further discloses that the interface-passivating organic coating may contain an ion conductor comprising magnesium compounds or aluminum compounds. The disclosed magnesium compounds include magnesium bis(trifluoromethylsulfonyl)imide, Mg(TFSI)₂, and magnesium perchlorate, MgClO₄ (CN’883, Pgs. 6-7). The disclosed aluminum compounds include Al₂O₃, Li₆.₂₈La₃Zr₂Al₀.₂₄O₁₂, and Li₁.₅Al₀.₅Ge₁.₅(PO₄)₃ (CN’883, Pgs. 6-7).
CN’883 teaches that these ion-conductor compounds are components of the organic coating provided on the electrode active material and that the coating reduces direct contact between the electrode active material and the electrolyte, inhibits interfacial side reactions, protects the active material from corrosion, and improves interface stability (CN’883, Pgs. 2-5). Accordingly, CN’883 discloses an interface passivator selected from at least one compound of magnesium or aluminum, as required by claim 6.
As to Claim 7:
CN’883 discloses the secondary battery according to claim 1, as set forth in the rejection of claim 1 above. CN’883 further discloses that the interface-passivating organic coating contains an ion conductor comprising a sulfonimide salt. Specifically, CN’883 identifies lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) as suitable lithium salts for the organic coating (CN’883, Pgs. 4 and 6-7). CN’883 also identifies Mg(TFSI)₂ and NaTFSI as suitable magnesium and sodium sulfonimide salts, respectively (CN’883, Pgs. 6-7).
CN’883 expressly incorporates LiTFSI into the organic coatings provided on the positive electrode active materials of Examples 1-3, and subsequently incorporates those coated active materials into the respective positive electrode material layers (CN’883, Pgs. 11-13). CN’883 teaches that the resulting organic coating reduces direct contact between the electrode active material and electrolyte, inhibits interfacial side reactions, and improves interfacial stability (CN’883, Pgs. 2-5). Accordingly, CN’883 discloses an interface passivator selected from at least one of the compound classes recited in claim 7, particularly a sulfonimide salt.
As to Claim 8:
CN’883 discloses the secondary battery according to claim 1, as set forth in the rejection of claim 1 above. CN’883 further discloses that the interface passivator is blended into the positive electrode material layer. Specifically, CN’883 prepares an interface-passivating organic coating by uniformly mixing a polymer product, an organic-silicon resin precursor, lithium-containing ion conductors including LiTFSI and LLZTO, and a positive electrode active material, followed by heating and curing to obtain organic-coating-covered positive electrode active material (CN’883, Pgs. 8-9 and 11-13).
CN’883 thereafter blends the passivator-containing coated positive active material with a conductive agent, binder, and solvent to prepare the positive electrode material layer. Examples 1-3 respectively blend organic-coating-covered LiNi₀.₈Co₀.₁Mn₀.₁O₂, LiCoO₂, or LiFePO₄ with conductive carbon and binder and apply the resulting positive electrode material mixture to an aluminum-foil current collector (CN’883, Pgs. 11-13). Accordingly, CN’883 discloses that the interface passivator is blended into the positive electrode material layer, as required by claim 8.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
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.
Claims 2-5, 9, 10, and 11 are rejected under 35 U.S.C. 103 as being unpatentable over CN 113707883 A (“CN’883”), as applied to Claim 1, and further in view of US 2020/0321655 A1 (“US’655”).
As to Claim 2:
CN’883 discloses the secondary battery of claim 1, as set forth in the rejection of claim 1. CN’883 further discloses an electrode active material comprising an active material and an organic coating layer coated on the surface of the active material, wherein the active material may be a positive electrode active material or a negative electrode active material (CN’883, Pgs. 4 and 8); the negative electrode active material may comprise a silicon-based material, including a silicon-carbon material or nanosilicon (CN’883, Pg. 8); the organic coating layer contains an ion conductor comprising a lithium salt and may further comprise a magnesium salt, wherein exemplary magnesium salts include Mg(TFSI)₂ and MgClO₄ (CN’883, Pg. 4); the electrode containing the coated active material may be a negative electrode; and the battery may comprise a positive electrode, a negative electrode containing the organic coating layer, and an electrolyte (CN’883, Pgs. 9-10). CN’883 additionally teaches that the surface coating reduces direct contact between the electrode active material and the electrolyte, thereby reducing interfacial side reactions and inhibiting expansion of a silicon-based negative electrode during battery cycling (CN’883, Pgs. 2-5).
However, CN’883 does not expressly disclose that, during at least one charging of the secondary battery, the magnesium-containing interface passivator reacts at the surface of the silicon-containing negative electrode material to form an A-D-E ternary layer, wherein A is an alkali-metal element different from E, D is silicon or carbon, and E is magnesium.
US’655 discloses lithium electrochemical cells having silicon-based negative electrodes and electrolyte compositions containing additional metal salts that improve the performance and stability of the silicon-based electrodes (US’655, [0002], [0007]-[0009]). US’655 explains that Zintl phases are products of reactions involving an alkali or alkaline-earth metal and a metalloid such as silicon (US’655, [0006]). US’655 further discloses that adding a metal salt containing Mg, Al, Ca, Sr, Sc, Y, or Ga to a lithium electrolyte promotes the in-situ formation of amorphous Li-M-Si ternary phases in silicon anodes during the charging process, and that these ternary phases initially form on the surfaces of the anode particles, protect the underlying lithiated-silicon phases, reduce side reactions with the electrolyte, and limit the effects of large volume changes (US’655, [0063]). Exemplary metal-salt additives include Mg(TFSI)₂ and Al(TFSI)₃, which are added to a lithium-salt electrolyte used in cells having silicon-containing electrodes (US’655, [0065]).
US’655 more particularly discloses that magnesium and lithium cations co-insert into a silicon electrode during lithiation, thereby forming less-reactive metal-substituted lithium-silicide species in situ and reducing the reactivity of the charged silicon anode (US’655, [0093]). Characterization of a silicon electrode lithiated in an electrolyte containing Mg(TFSI)₂ showed the formation of Li₁₅₋ₓMgₓSi₄ phases, including a specifically confirmed Li₁₄.₆₅Mg₀.₃₅Si₄ ternary phase (US’655, [0096]). US’655 also reports that magnesium was present both on the surface and in the bulk of the lithiated silicon particles and concludes that the magnesium-containing electrolyte permits co-insertion of magnesium into silicon during lithiation, forming Li-Mg-Si ternaries (US’655, [0097]). Accordingly, the lithium component corresponds to A, the alkali-metal component of the ternary Zintl phase; silicon corresponds to D; and magnesium corresponds to E, which is different from lithium. US’655 therefore teaches a Li-Si-Mg A-D-E ternary layer formed at the surface of a silicon-containing negative electrode through reaction and co-insertion of the magnesium-salt passivator during charging.
CN’883 and US’655 are analogous arts because both references concern lithium secondary batteries having silicon-containing negative electrodes and address the same interfacial problems caused by silicon-electrode expansion and reactions between lithiated silicon and the electrolyte. CN’883 addresses these problems by placing a lithium-ion-conductive, magnesium-salt-containing passivating coating on the electrode active-material surface to reduce side reactions and electrode expansion (CN’883, Pgs. 2-5), while US’655 addresses the same problems by using a magnesium-salt additive that forms a stabilizing Li-Mg-Si surface phase during charging (US’655, [0002]-[0008], [0013], [0063]).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to modify the secondary battery of CN’883 by employing CN’883’s disclosed Mg(TFSI)₂ interface passivator in an electrochemically available form at the silicon-containing negative-electrode interface, including by additionally incorporating Mg(TFSI)₂ into the lithium electrolyte contacting the silicon-containing negative electrode as taught by US’655, such that lithium and magnesium co-insert into the silicon during charging and form a Li-Si-Mg ternary layer initially on the surface of the negative-electrode active-material particles. A person skilled in the art would have been motivated to make this modification because US’655 expressly teaches that the resulting Li-Mg-Si surface phase protects the underlying lithiated silicon, reduces electrolyte side reactions, limits the effects of silicon volume changes, and improves capacity retention, cycling performance, and coulombic efficiency (US’655, [0063], [0065]-[0066], [0093]-[0097]).
As to Claim 3:
CN’883 discloses the secondary battery according to claim 2, except for the charging-formed A-D-E ternary-layer limitation addressed below; see also the rejection of claim 2. CN’883 discloses an organic interface-passivating coating formed on the surface of an electrode active material, wherein the active material may be a positive electrode active material or a negative electrode active material (CN’883, Pgs. 4 and 8). The coating reduces direct contact between the electrode active material and electrolyte, reduces interfacial side reactions, and inhibits electrode expansion during cycling (CN’883, Pgs. 2-5).
CN’883 further discloses that the organic coating contains an ion conductor at 1-20 wt% of the coating, including expressly identified values of 1 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt% (CN’883, Pgs. 3 and 6-7); the ion conductor contains a lithium salt and may further contain a magnesium salt, with expressly identified lithium-salt-to-magnesium-salt mass ratios of 1:0.1, 1:0.2, 1:0.5, 1:0.8, and 1:1 (CN’883, Pgs. 4 and 6-7); and the magnesium salt may be Mg(TFSI)₂ or MgClO₄ (CN’883, Pgs. 4 and 7). Thus, CN’883 identifies the magnesium salt as a compound containing magnesium and located in the interface-passivating coating.
CN’883 also discloses an active-material-to-organic-coating mass ratio of 100:0.1 to 100:5, including an expressly identified ratio of 100:5 (CN’883, Pg. 8), and an electrode material layer containing 90 wt% coated active material, 5 wt% binder, and 5 wt% conductive material (CN’883, Pgs. 9 and 11). Applying CN’883’s expressly disclosed values of a 100:5 active-material-to-coating ratio, 20 wt% ion conductor in the coating, a 1:1 lithium-salt-to-magnesium-salt ratio in the ion conductor, and 90 wt% coated active material in the positive-electrode material layer results in approximately 0.43 wt% magnesium salt based on the total weight of the positive-electrode material layer. Specifically, five mass parts of coating contain one mass part of ion conductor, of which 0.5 mass part is magnesium salt; the magnesium salt therefore constitutes 0.5/105 of the coated active material, which, when the coated active material constitutes 90 wt% of the positive-electrode material layer, corresponds to approximately 0.43 wt% of the total positive-electrode material layer. This amount falls within the claimed range of 0.001-20 wt%.
CN’883 further discloses that the organic coating is applied to the positive active material, the coated positive active material is incorporated into the positive-electrode material layer, and the lithium-ion battery is thereafter assembled before cycle testing is performed (CN’883, Pgs. 10-11). Therefore, the magnesium-containing interface passivator is present in the positive-electrode material layer at the disclosed concentration before the battery undergoes charging.
As to Claim 4:
CN’883 discloses the secondary battery according to claim 2, except for the charging-formed A-D-E ternary-layer limitation addressed below; see also the rejection of claim 2. CN’883 discloses an electrode active material comprising an active material and an organic interface-passivating coating formed on the surface of the active material, wherein the active material may be a negative electrode active material (CN’883, Pgs. 4 and 8). The negative electrode active material may comprise a silicon-based material, including a silicon-carbon material or nanosilicon, and the electrode containing the coated active material may be a negative electrode (CN’883, Pgs. 8-9). CN’883 further discloses a battery comprising a positive electrode, a negative electrode containing the organic coating layer, and an electrolyte (CN’883, Pg. 10).
CN’883 discloses that the organic coating contains an ion conductor at 1-20 wt% of the coating, including expressly identified values of 1 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt% (CN’883, Pgs. 3 and 6-7); the ion conductor contains a lithium salt and may further contain a magnesium salt, with expressly identified lithium-salt-to-magnesium-salt mass ratios of 1:0.1, 1:0.2, 1:0.5, 1:0.8, and 1:1 (CN’883, Pgs. 4 and 6-7); and the magnesium salt may be Mg(TFSI)₂ or MgClO₄ (CN’883, Pgs. 4 and 7). Thus, CN’883 identifies the magnesium salt as a compound containing magnesium and located in the interface-passivating coating on the negative electrode active material.
CN’883 also discloses an active-material-to-organic-coating mass ratio of 100:0.1 to 100:5, including an expressly identified ratio of 100:5 (CN’883, Pg. 8). In Embodiment 5, CN’883 prepares coated silicon oxide active material before battery assembly and incorporates the coated SiOₓ material into an electrode material layer containing 85 wt% coated SiOₓ active material, 7 wt% conductive agents, and 8 wt% binder (CN’883, Pg. 14).
Applying CN’883’s expressly disclosed values of a 100:5 active-material-to-coating ratio, 20 wt% ion conductor in the coating, a 1:1 lithium-salt-to-magnesium-salt ratio in the ion conductor, and 85 wt% coated active material in the negative electrode material layer results in approximately 0.40 wt% magnesium salt based on the total weight of the negative electrode material layer. Specifically, five mass parts of coating contain one mass part of ion conductor, of which 0.5 mass part is magnesium salt. The magnesium salt therefore constitutes 0.5/105 of the coated active material, which, when the coated active material constitutes 85 wt% of the negative electrode material layer, corresponds to approximately 0.40 wt% of the total negative electrode material layer. This amount falls within the claimed range of 0.001-20 wt%.
CN’883 further discloses that the organic coating is first formed on the silicon oxide active material, the coated material is then incorporated into the electrode material layer, the lithium-ion battery is thereafter assembled, and charge-discharge testing is subsequently performed (CN’883, Pgs. 10 and 14). Therefore, the magnesium-containing interface passivator is present in the negative electrode material layer at the disclosed concentration before the battery undergoes at least one charging.
As to Claim 5:
CN’883 discloses the secondary battery according to claim 2, except for the charging-formed A-D-E ternary-layer limitation addressed below; see also the rejection of claim 2. CN’883 discloses an electrode active material comprising an active material and an organic interface-passivating coating formed on the surface of the active material, wherein the coating contains an ion conductor (CN’883, Pgs. 3-4 and 6-8). The ion conductor contains a lithium salt and may further contain a magnesium salt, and exemplary magnesium salts include Mg(TFSI)₂ and MgClO₄ (CN’883, Pgs. 4 and 6-7). CN’883 also discloses a secondary battery comprising a positive electrode, a negative electrode, and an electrolyte disposed between and contacting the electrodes (CN’883, Pgs. 9-10).
CN’883 further teaches that the magnesium-salt-containing coating reduces direct contact between the electrode active material and electrolyte, thereby reducing interfacial side reactions, and that the coating inhibits electrode expansion during battery cycling (CN’883, Pgs. 2-5). CN’883 therefore identifies Mg(TFSI)₂ and MgClO₄ as interface-passivating compounds suitable for stabilizing the electrode-electrolyte interface in a lithium secondary battery.
However, CN’883 does not expressly disclose that, before at least one charging, the electrolyte itself contains the magnesium-containing interface passivator at 0.001-20 wt% based on the total weight of the electrolyte. CN’883 also does not expressly disclose the limitation inherited from claim 2 that the magnesium-containing interface passivator reacts during charging to form an A-D-E ternary layer on the surface of the silicon-containing negative electrode material.
US’655 discloses a lithium electrochemical cell having a silicon-containing negative electrode and a lithium electrolyte containing an additional metal-salt additive before electrochemical cycling (US’655, [0008]-[0011], [0063]-[0065]). The additional metal salt may be a magnesium salt, including Mg(TFSI)₂, and may be present at a concentration from approximately 0.001 M to approximately 5 M (US’655, [0009], [0063], [0065]). US’655 further identifies approximately 0.1-0.2 M as a relatively low and effective concentration range for stabilizing silicon-containing anodes through in-situ formation of Li-M-Si ternary phases during charging (US’655, [0013]).
US’655 specifically discloses preparing a GenFM electrolyte by adding 0.1 M Mg(TFSI)₂ to a lithium-salt electrolyte before the electrolyte is used in the electrochemical cell and before formation cycling is performed (US’655, [0086]-[0088], [0093]-[0094]). US’655 also evaluates an electrolyte containing 0.2 M Mg(TFSI)₂ and teaches that doubling the magnesium concentration from 0.1 M to 0.2 M provides no obvious additional capacity or cyclability benefit, thereby indicating that the lower concentration supplies sufficient magnesium for the co-insertion process (US’655, [0105]). US’655 thus expressly identifies magnesium-salt concentration as a selectable formulation parameter and teaches using a relatively low concentration sufficient to obtain the desired interface-stabilizing effect without requiring an unnecessary excess of magnesium salt.
US’655 further discloses that magnesium and lithium cations supplied by the electrolyte co-insert into a silicon electrode during lithiation, forming less-reactive metal-substituted lithium-silicide species in situ (US’655, [0093]). The magnesium-containing electrolyte produces Li₁₅₋ₓMgₓSi₄ phases, including a specifically confirmed Li₁₄.₆₅Mg₀.₃₅Si₄ ternary phase (US’655, [0096]). Magnesium is detected both at the surface and in the bulk of the lithiated silicon particles, confirming that the Mg-containing electrolyte forms Li-Mg-Si ternaries during lithiation (US’655, [0097]). US’655 explains that these ternary phases initially form at the surfaces of the silicon anode particles, protect the underlying lithiated-silicon phases, reduce electrolyte side reactions, and limit the effects of silicon volume changes (US’655, [0063]). Accordingly, lithium corresponds to A, silicon corresponds to D, and magnesium corresponds to E in the claimed A-D-E ternary layer.
Although US’655 expresses the magnesium-salt amount in molarity rather than weight percent, US’655 expressly teaches a broad selectable concentration range of approximately 0.001-5 M, identifies approximately 0.1-0.2 M as the effective low-concentration region, demonstrates successful operation at 0.1 M Mg(TFSI)₂, and teaches that increasing the amount to 0.2 M provides no obvious additional benefit (US’655, [0009], [0013], [0063], [0093]-[0094], [0105]). These teachings would have directed a person skilled in the art to select a relatively low but effective amount of Mg(TFSI)₂, including an amount that, when expressed on a total-electrolyte weight basis, falls within the claimed broad range of 0.001-20 wt%.
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to modify the secondary battery of CN’883 by additionally incorporating CN’883’s disclosed Mg(TFSI)₂ interface passivator into the electrolyte before charging, as taught by US’655, and to select its concentration so that the passivator constitutes 0.001-20 wt% based on the total electrolyte weight. US’655 expressly teaches varying the Mg(TFSI)₂ concentration over a broad range, identifies a low effective concentration of approximately 0.1 M, and teaches that increasing the concentration to 0.2 M provides no obvious additional capacity or cycling benefit (US’655, [0009], [0013], [0093]-[0094], [0105]). Thus, the references themselves provide a reason to select a relatively low amount within the claimed range: to supply sufficient magnesium for co-insertion and formation of the protective Li-Si-Mg ternary phase while avoiding unnecessary additional magnesium salt. Upon charging, the electrolyte-borne magnesium and lithium would co-insert into the silicon negative electrode and form the claimed Li-Si-Mg ternary surface layer, thereby reducing side reactions, limiting silicon volume-change effects, and improving capacity retention and cycling performance (US’655, [0063], [0093]-[0097]).
As to Claim 9:
CN’883 discloses the secondary battery according to claim 2, except for the charging-formed A-D-E ternary-layer limitation addressed below; see also the rejection of claim 2. CN’883 discloses an electrode active material comprising an active material and an organic interface-passivating coating formed on the surface of the active material, wherein the active material may be a negative electrode active material (CN’883, Pgs. 4 and 8). The negative electrode active material may comprise a silicon-based material, including a silicon-carbon material or nanosilicon (CN’883, Pg. 8), and the battery may comprise a positive electrode, a coated negative electrode, and an electrolyte (CN’883, Pgs. 9-10).
CN’883 further discloses that the organic coating contains an ion conductor comprising a lithium salt and may additionally contain a magnesium salt, wherein the magnesium salt may be Mg(TFSI)₂ or MgClO₄ (CN’883, Pgs. 4 and 6-7). CN’883 therefore teaches a lithium secondary battery having a silicon-containing negative electrode and a magnesium-containing interface passivator at the electrode interface. CN’883 also teaches that the interface-passivating coating reduces direct contact between the electrode active material and electrolyte, reduces interfacial side reactions, and inhibits expansion of the silicon-containing electrode during battery cycling (CN’883, Pgs. 2-5).
However, CN’883 does not expressly disclose that, during at least one charging of the secondary battery, the magnesium-containing interface passivator reacts at the surface of the silicon-containing negative electrode to form a Li-Si-Mg ternary layer, which is one of the alternatives expressly recited in claim 9.
US’655 discloses a lithium electrochemical cell having a silicon-containing negative electrode and a lithium electrolyte containing an additional magnesium salt, including Mg(TFSI)₂ (US’655, [0008]-[0011], [0063]-[0065]). US’655 teaches that magnesium-salt additives stabilize silicon-anode chemistry through in-situ formation of Li-M-Si ternary phases during charging (US’655, [0013]). More particularly, US’655 discloses that a magnesium salt promotes in-situ formation of an amorphous Li-Mg-Si ternary phase in a silicon anode during charging, and that the ternary phase initially forms on the surfaces of the anode particles, protects the underlying lithiated-silicon phases, reduces side reactions with the electrolyte, and limits the effects of large volume changes (US’655, [0063]).
US’655 further discloses that magnesium and lithium cations co-insert into a silicon electrode during lithiation, forming less-reactive magnesium-substituted lithium-silicide species in situ (US’655, [0093]). X-ray characterization of a silicon electrode lithiated in an electrolyte containing Mg(TFSI)₂ showed formation of Li₁₅₋ₓMgₓSi₄ phases and specifically confirmed a Li₁₄.₆₅Mg₀.₃₅Si₄ ternary phase (US’655, [0096]). Energy-dispersive spectroscopy further showed magnesium at both the surface and in the bulk of the lithiated silicon particles, confirming that magnesium co-inserts into silicon during lithiation and forms Li-Mg-Si ternaries (US’655, [0097]). US’655 summarizes that Li-M-Si ternary phases are formed in charged silicon electrodes through electrochemical co-insertion after addition of magnesium, calcium, or aluminum salt additives to the electrolyte (US’655, [0113]). Thus, US’655 expressly teaches the claimed Li-Si-Mg ternary-layer alternative.
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to modify the secondary battery of CN’883 by employing CN’883’s disclosed Mg(TFSI)₂ interface passivator in an electrochemically available form at the silicon-containing negative-electrode interface, including by additionally incorporating Mg(TFSI)₂ into the lithium electrolyte contacting the silicon negative electrode as taught by US’655, such that lithium and magnesium co-insert into silicon during charging and form a Li-Si-Mg ternary layer initially at the surface of the negative-electrode active-material particles. The reason for making this modification is expressly provided by US’655: formation of the Li-Si-Mg ternary surface phase protects the underlying lithiated silicon, reduces electrolyte side reactions, limits the effects of silicon volume changes, and improves capacity retention, cycling performance, and coulombic efficiency (US’655, [0063], [0065]-[0066], [0093]-[0097]). Because Li-Si-Mg is expressly included among the ternary-layer alternatives recited in claim 9, the proposed combination meets the additional limitation of claim 9.
Claims 10 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over CN 113707883 A (“CN’883”), as applied to Claim 1, and further in view of US 2022/0077466 A1 (“US’466”).
As to Claim 10:
CN’883 discloses the secondary battery of claim 1, as set forth in the rejection of claim 1. In particular, CN’883 discloses a lithium-ion secondary battery containing positive and negative electrode material layers and an electrolyte. CN’883 further discloses an organic coating on the electrode active material that functions as an interface passivator by reducing direct contact between the active material and electrolyte, thereby reducing interfacial side reactions and electrode expansion. The coating contains an ion conductor comprising a lithium salt and may further contain a magnesium salt, including Mg(TFSI)₂ or MgClO₄ (CN’883, Pgs. 3-4). CN’883 teaches that the coated active material may be a positive or negative electrode active material and identifies graphite as a negative electrode active material (CN’883, Pg. 8). CN’883 also discloses electrodes containing the active material and batteries containing positive and negative electrodes and an electrolyte (CN’883, Pgs. 9-10). Example 1 specifically prepares a negative electrode material layer using artificial graphite active material and assembles the resulting negative electrode with a coated positive electrode and a LiPF₆-based electrolyte to form a lithium-ion secondary battery (CN’883, Pg. 11).
However, CN’883 does not expressly disclose that its negative electrode active material has a D50 of 1 μm to 20 μm.
US’466 discloses a negative electrode active material for a lithium secondary battery comprising a graphite material having secondary particles (US’466, [0036]). US’466 defines D50 as the particle size at which the active-material particles accumulate to 50% by volume (US’466, [0046]). US’466 expressly teaches that the D50 of the graphite secondary particles may be 11 μm to 25 μm, more particularly 12 μm to 20 μm, and still more particularly 15 μm to 18 μm (US’466, [0051]). Thus, US’466’s expressly disclosed ranges of 12 μm to 20 μm and 15 μm to 18 μm fall entirely within the claimed range of 1 μm to 20 μm. US’466 also provides a working example in which graphite secondary particles have a D50 of 15.1 μm, are made into a slurry containing 97 wt% negative electrode active material, and are applied to a copper current collector to produce a negative electrode (US’466, [0138]-[0141]).
CN’883 and US’466 are analogous art because both references concern negative electrode active materials for lithium secondary batteries, particularly graphite-based negative electrode materials, and both address battery performance associated with the negative electrode. CN’883 seeks to reduce interfacial side reactions and electrode expansion in lithium-ion batteries (CN’883, Pgs. 2-3), while US’466 seeks to provide graphite negative electrode active material having reduced expansion and improved charging and discharging characteristics (US’466, [0027], [0040]).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to use, as the graphite negative electrode active material disclosed by CN’883, the graphite secondary particles of US’466 having a D50 of 12 μm to 20 μm or 15 μm to 18 μm. US’466 expressly teaches that particle sizes below its disclosed range can increase electrode expansion and specific surface area and reduce battery efficiency, whereas particle sizes above the range can reduce tap density and make formation of an electrode having suitable density more difficult (US’466, [0053]-[0054]). Accordingly, the proposed modification is supported by US’466’s express teaching that the disclosed D50 range provides graphite negative electrode active material suitable for forming a secondary-battery electrode while addressing expansion, efficiency, tap-density, and electrode-performance considerations. The resulting CN’883 battery would therefore comprise a negative electrode material layer containing a negative electrode active material having a D50 within the claimed range of 1 μm to 20 μm.
As to Claim 11:
CN’883 discloses the secondary battery of claim 1, as set forth in the rejection of claim 1. In particular, CN’883 discloses a lithium-ion secondary battery containing positive and negative electrode material layers and an electrolyte. CN’883 further discloses an organic coating on the electrode active material that functions as an interface passivator by reducing direct contact between the active material and electrolyte, thereby reducing interfacial side reactions and electrode expansion. The coating contains an ion conductor comprising a lithium salt and may further contain a magnesium salt, including Mg(TFSI)₂ or MgClO₄ (CN’883, Pgs. 3-4). CN’883 teaches that the coated active material may be a positive or negative electrode active material and identifies graphite as a negative electrode active material (CN’883, Pg. 8). CN’883 also discloses electrodes containing the active material and batteries containing positive and negative electrodes and an electrolyte (CN’883, Pgs. 9-10). Example 1 specifically prepares a negative electrode material layer using artificial graphite active material and assembles the resulting negative electrode with a coated positive electrode and a LiPF₆-based electrolyte to form a lithium-ion secondary battery (CN’883, Pg. 11).
However, CN’883 does not expressly disclose that its negative electrode active material has a Span value of 0.9 to 1.8, calculated according to Span = (D90 − D10)/D50, where D90, D10, and D50 denote particle sizes at cumulative distribution percentages of 90%, 10%, and 50%, respectively.
US’466 discloses a negative electrode active material for a lithium secondary battery comprising a graphite material having secondary particles, wherein the ratio (D90 − D10)/D50 is 1.0 to 1.32 (US’466, [0036], [0042]). US’466 further discloses a narrower span range of 1.0 to 1.2 (US’466, [0043]). Thus, both of US’466’s disclosed ranges fall entirely within the claimed Span range of 0.9 to 1.8.
US’466 expressly identifies the ratio (D90 − D10)/D50 as the “span value” and states that the span value is calculated using D10, D50, and D90 as particle-size indices (US’466, [0044]-[0045]). US’466 further explains that D10, D50, and D90 represent the particle sizes at which the active-material particles cumulatively reach 10%, 50%, and 90% by volume, respectively (US’466, [0046]). Accordingly, US’466 teaches both the claimed Span equation and the claimed meanings of D10, D50, and D90.
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to use, as the graphite negative electrode active material disclosed by CN’883, the graphite secondary particles of US’466 having a Span value of 1.0 to 1.32 or 1.0 to 1.2, calculated according to Span = (D90 − D10)/D50. US’466 expressly teaches that an excessively small span value can reduce production yield, electrolyte wetting, ion conductivity, and the ability to obtain high tap density, while an excessively large span value can increase specific surface area and slurry viscosity, reduce initial charging and discharging efficiency, and make production of a uniformly coated electrode difficult (US’466, [0047]-[0049]). US’466 therefore teaches controlling the span value to 1.0 to 1.32 to control the particle-size deviation of the graphite secondary particles (US’466, [0050]). The resulting CN’883 battery would comprise a negative electrode material layer containing a negative electrode active material having the claimed Span value and particle-size distribution parameters.
Claims 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over CN 113707883 A (“CN’883”), as applied to Claim 1, and further in view of EP 3923385 A1 (“EP’385”).
As to Claim 12:
CN’883 discloses the secondary battery according to claim 1, as set forth in the rejection of claim 1. In particular, CN’883 discloses a lithium-ion secondary battery containing positive and negative electrode material layers and an electrolyte. CN’883 further discloses an organic coating on the electrode active material that functions as an interface passivator by reducing direct contact between the electrode active material and electrolyte, thereby reducing interfacial side reactions and electrode expansion. The coating contains an ion conductor comprising a lithium salt and may further contain a magnesium salt, including Mg(TFSI)₂ or MgClO₄ (CN’883, Pgs. 3-4). CN’883 teaches that the coated active material may be a positive or negative electrode active material and identifies graphite and silicon-based materials as negative electrode active materials (CN’883, Pg. 8). CN’883 also discloses a secondary battery containing positive and negative electrodes and an electrolyte (CN’883, Pgs. 9-10). Example 1 specifically assembles a coated positive electrode, an artificial-graphite negative electrode, and a LiPF₆-based electrolyte into a soft-packaged lithium-ion secondary battery (CN’883, Pg. 11).
However, CN’883 does not expressly disclose a battery module comprising its secondary battery.
EP’385 discloses a secondary battery and expressly provides a battery module comprising the secondary battery (EP’385, Pg. 5). EP’385 further teaches that a secondary battery may be assembled into a battery module and that the battery module may include a plurality of secondary batteries, with the number of secondary batteries adjusted according to the application and desired capacity of the battery module (EP’385, Pg. 12). EP’385 illustrates a battery module 4 in which a plurality of secondary batteries 5 are arranged in the module and fixed by fasteners. EP’385 also teaches that the module may include a housing having a receiving space in which the plurality of secondary batteries is received (EP’385, Pg. 12). Thus, EP’385 expressly teaches the missing limitation of a battery module comprising a secondary battery.
CN’883 and EP’385 are analogous art because both references relate to secondary batteries and electrode active materials used in secondary batteries. CN’883 concerns electrode materials and lithium-ion secondary batteries having improved interfacial and cycle performance (CN’883, Pgs. 2-3), while EP’385 concerns negative electrode active materials, secondary batteries containing those materials, and battery modules containing the secondary batteries (EP’385, Pgs. 2, 5). Both references therefore address secondary-battery structures and the use of electrode materials in secondary-battery applications.
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to assemble one or more of the lithium-ion secondary batteries disclosed by CN’883 into the battery-module arrangement taught by EP’385. EP’385 expressly teaches assembling secondary batteries into a battery module and adjusting the number of secondary batteries according to the application and desired capacity of the module (EP’385, Pg. 12). EP’385 further provides an express arrangement for the combination by positioning a plurality of secondary batteries in a module, fixing the batteries with fasteners, and optionally receiving the batteries in a module housing (EP’385, Pg. 12). The resulting assembly would be a battery module comprising the secondary battery according to claim 1, as required by claim 12.
As to Claim 13:
CN’883 discloses the secondary battery according to claim 1, as set forth in the rejection of claim 1. In particular, CN’883 discloses a lithium-ion secondary battery containing positive and negative electrode material layers and an electrolyte. CN’883 further discloses an organic coating on the electrode active material that functions as an interface passivator by reducing direct contact between the electrode active material and electrolyte, thereby reducing interfacial side reactions and electrode expansion. The coating contains an ion conductor comprising a lithium salt and may further contain a magnesium salt, including Mg(TFSI)₂ or MgClO₄ (CN’883, Pgs. 3-4). CN’883 teaches that the coated active material may be a positive or negative electrode active material (CN’883, Pg. 8) and discloses secondary batteries containing positive and negative electrodes and an electrolyte (CN’883, Pgs. 9-10). Example 1 specifically assembles a coated positive electrode, an artificial-graphite negative electrode, and a LiPF₆-based electrolyte into a soft-packaged lithium-ion secondary battery (CN’883, Pg. 11). As set forth in the rejection of claim 12, CN’883 in view of EP’385 further renders obvious a battery module comprising the secondary battery.
However, CN’883 does not expressly disclose a battery pack comprising a battery module.
EP’385 expressly discloses a battery module comprising a secondary battery and a battery pack comprising the battery module (EP’385, Pg. 5). EP’385 further teaches that secondary batteries may be assembled into a battery module, with the number of secondary batteries selected according to the application and desired capacity of the module. A plurality of secondary batteries may be arranged within the module, fixed by fasteners, and received within a module housing (EP’385, Pg. 12). EP’385 then teaches that the battery module may be assembled into a battery pack and that the number of battery modules included in the battery pack may be adjusted according to the application and desired capacity of the battery pack (EP’385, Pg. 12). EP’385 illustrates a battery pack having a battery case and a plurality of battery modules disposed within the battery case, with the battery case including upper and lower case bodies that define a space for receiving the modules (EP’385, Pg. 12). Thus, EP’385 expressly teaches the missing limitation of a battery pack comprising the battery module.
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to assemble the battery modules containing the CN’883 secondary batteries, as rendered obvious by EP’385 in the rejection of claim 12, into the battery-pack arrangement taught by EP’385. EP’385 expressly teaches assembling battery modules into a battery pack and adjusting the number of modules according to the application and desired capacity of the battery pack (EP’385, Pg. 12). EP’385 further provides an express arrangement for the combination by disposing a plurality of battery modules in a battery case having upper and lower case bodies (EP’385, Pg. 12). The resulting assembly would be a battery pack comprising the battery module according to claim 12, as required by claim 13.
As to Claim 14:
CN’883 discloses the secondary battery according to claim 1, as set forth in the rejection of claim 1. In particular, CN’883 discloses a lithium-ion secondary battery containing positive and negative electrode material layers and an electrolyte. CN’883 further discloses an organic coating on the electrode active material that functions as an interface passivator by reducing direct contact between the electrode active material and electrolyte, thereby reducing interfacial side reactions and electrode expansion. The coating contains an ion conductor comprising a lithium salt and may further contain a magnesium salt, including Mg(TFSI)₂ or MgClO₄ (CN’883, Pgs. 3-4). CN’883 teaches that the coated active material may be a positive or negative electrode active material (CN’883, Pg. 8) and discloses secondary batteries containing positive and negative electrodes and an electrolyte (CN’883, Pgs. 9-10). Example 1 specifically assembles a coated positive electrode, an artificial-graphite negative electrode, and a LiPF₆-based electrolyte into a soft-packaged lithium-ion secondary battery (CN’883, Pg. 11).
However, CN’883 does not expressly disclose a powered device comprising its secondary battery.
EP’385 expressly discloses an apparatus comprising a secondary battery and illustrates an apparatus that uses the secondary battery as a power source (EP’385, Pg. 5). EP’385 further teaches that the secondary battery, battery module, or battery pack may be used as a power source for the apparatus or as an energy-storage unit for the apparatus (EP’385, Pg. 13). EP’385 identifies examples of the powered apparatus including a mobile phone, notebook computer, pure electric vehicle, hybrid electric vehicle, plug-in hybrid electric vehicle, electric bicycle, electric scooter, electric golf vehicle, electric truck, electric train, ship, and satellite (EP’385, Pg. 13). EP’385 also expressly teaches using a battery module or battery pack to meet the high-power and high-energy-density requirements of an electric vehicle and using the secondary battery as the power source for a mobile phone, tablet computer, or notebook computer (EP’385, Pg. 13). Thus, EP’385 expressly teaches the missing limitation of a powered device comprising a secondary battery.
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to incorporate the lithium-ion secondary battery disclosed by CN’883 into the powered apparatus taught by EP’385 and use the secondary battery as a power source for that apparatus. EP’385 expressly teaches selecting and using a secondary battery, battery module, or battery pack as the power source for an apparatus according to the requirements of the particular application (EP’385, Pg. 13). EP’385 further identifies specific powered-device applications, including mobile electronic devices and electric vehicles, and teaches using secondary batteries to satisfy the devices’ power and energy requirements (EP’385, Pg. 13). The resulting combination would be a powered device comprising the secondary battery according to claim 1, as required by claim 14.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
EP 3096379 A1 discloses a negative electrode material for a non-aqueous electrolyte secondary battery, which contains negative electrode active material particles containing a silicon compound expressed by SiOx.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JIMMY K VO whose telephone number is (571)272-3242. The examiner can normally be reached Monday - Friday, 8 am to 6 pm EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Tong Guo can be reached at (571) 272-3066. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JIMMY VO/
Primary Examiner
Art Unit 1723
/JIMMY VO/ Primary Examiner, Art Unit 1723
Prosecution Insights