10 newer rulings cite the same tariff codes.
Classification can shift over time. Review the more recent rulings below before relying on this one.
The country of origin of a silicon anode active material
Issued October 16, 2025 by U.S. Customs and Border Protection.
Cite this ruling
Copies to clipboardN3 N351688 (October 16, 2025)
Tariff classification
Product description
, Ltd. for a silicon anode active material (Silicon AAM) that subsequent to its importation into the United States will be part of the anode of a rechargeable lithium-ion battery that will be incorporated into premium electric vehicles and advanced military equipment. You describe the manufacturing process as follows: In Korea, silicon monoxide from either Country A or B undergoes a pulverization process. It is then mixed with a carbon precursor sourced in Country C. The mixture is subjected to a high temperature heat treatment under controlled conditions. During this step, volatile organic compounds and impurities in the carbon precursor are removed and the remaining carbon content undergoes carbonization, being transformed into a layer of amorphous carbon that envelopes the silicon monoxide particles. After this treatment, a deagglomeration process is applied to separate the carbon coated particles and exclude certain large diameter particles. After this process is completed, the material is sent to the United States for its ultimate incorporation into the lithium-ion battery. When determining the country of origin for purposes of applying current trade remedies under Section 301 and additional duties, the substantial transformation analysis is applicable. See, e.g., Headquarters Ruling Letter H301619, dated November 6, 2018. The test for determining whether a substantial transformation will occur is whether an article emerges from a process with a new name, character, or use different from that possessed by the article prior to processing. See Texas Instruments Inc. v. United States, 681 F.2d 778 (C.C.P.A. 1982). This determination is based on the totality of the evidence. See National Hand Tool Corp. v. United States, 16 C.I.T. 308 (1992), aff’d, 989 F.2d 1201 (Fed. Cir. 1993). The silicon monoxide undergoes a change in character based on the processing done in Korea. The silicon monoxide is coated with the carbon precursor which changes the physical surface are
CBP rationale
substantial transformation analysis is applicable. See, e.g., Headquarters Ruling Letter H301619, dated November 6, 2018. The test for determining whether a substantial transformation will occur is whether an article emerges from a process with a new name, character, or use different from that possessed by the article prior to processing. See Texas Instruments Inc. v. United States, 681 F.2d 778 (C.C.P.A. 1982). This determination is based on the totality of the evidence. See National Hand Tool Corp. v. United States, 16 C.I.T. 308 (1992), aff’d, 989 F.2d 1201 (Fed. Cir. 1993). The silicon monoxide undergoes a change in character based on the processing done in Korea. The silicon monoxide is coated with the carbon precursor which changes the physical surface area, the individual size, and chemical composition of the particles. Certain other electrochemical character changes in relation to the function of the lithium-ion battery such as enhanced electrical conductivity, faster capacity attainment during the initial charging of the battery, and increased battery capacity retention over repeated recharging cycles (thus extending the battery’s usable life) are also obtained. Without this type of carbon-based coating, a silicon anode lithium-ion battery would have severe limitations that would outweigh any theoretical benefits that could be obtained over using a different material to coat the battery’s anodes. The processes performed in Korea change the silicon monoxide into a material that can be used as an anode on a lithium-ion battery, thereby resulting in a change in character of the silicon monoxide and in its use for this particular case. The country of origin of the Silicon AAM for purposes of Section 301 remedies will be Korea, and Section 301 duties will not apply. The holding set forth above applies only to the specific factual situation and merchandise description as identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations (CFR), Section 177.
Full text
N351688
October 16, 2025
OT:RR:NC:N3:139
CATEGORY: Origin Peter Paik Kim & Chang 75, Saemunan-ro, Jongno-gu Seoul 03182 Korea RE: The country of origin of a silicon anode active material Dear Mr. Paik: In your letter dated July 25, 2025, you requested a country of origin ruling on behalf of your client POSCO Silicon Solution, Co., Ltd. for a silicon anode active material (Silicon AAM) that subsequent to its importation into the United States will be part of the anode of a rechargeable lithium-ion battery that will be incorporated into premium electric vehicles and advanced military equipment. You describe the manufacturing process as follows: In Korea, silicon monoxide from either Country A or B undergoes a pulverization process. It is then mixed with a carbon precursor sourced in Country C. The mixture is subjected to a high temperature heat treatment under controlled conditions. During this step, volatile organic compounds and impurities in the carbon precursor are removed and the remaining carbon content undergoes carbonization, being transformed into a layer of amorphous carbon that envelopes the silicon monoxide particles. After this treatment, a deagglomeration process is applied to separate the carbon coated particles and exclude certain large diameter particles. After this process is completed, the material is sent to the United States for its ultimate incorporation into the lithium-ion battery. When determining the country of origin for purposes of applying current trade remedies under Section 301 and additional duties, the substantial transformation analysis is applicable. See, e.g., Headquarters Ruling Letter H301619, dated November 6, 2018. The test for determining whether a substantial transformation will occur is whether an article emerges from a process with a new name, character, or use different from that possessed by the article prior to processing. See Texas Instruments Inc. v. United States, 681 F.2d 778 (C.C.P.A. 1982). This determination is based on the totality of the evidence. See National Hand Tool Corp. v. United States, 16 C.I.T. 308 (1992), aff’d, 989 F.2d 1201 (Fed. Cir. 1993). The silicon monoxide undergoes a change in character based on the processing done in Korea. The silicon monoxide is coated with the carbon precursor which changes the physical surface area, the individual size, and chemical composition of the particles. Certain other electrochemical character changes in relation to the
function of the lithium-ion battery such as enhanced electrical conductivity, faster capacity attainment during the initial charging of the battery, and increased battery capacity retention over repeated recharging cycles (thus extending the battery’s usable life) are also obtained. Without this type of carbon-based coating, a silicon anode lithium-ion battery would have severe limitations that would outweigh any theoretical benefits that could be obtained over using a different material to coat the battery’s anodes. The processes performed in Korea change the silicon monoxide into a material that can be used as an anode on a lithium-ion battery, thereby resulting in a change in character of the silicon monoxide and in its use for this particular case. The country of origin of the Silicon AAM for purposes of Section 301 remedies will be Korea, and Section 301 duties will not apply. The holding set forth above applies only to the specific factual situation and merchandise description as identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations (CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and complete in every material respect. In the event that the facts are modified in any way, or if the goods do not conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2. Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic verification by CBP. This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection Regulations (19 C.F.R. 177). A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact National Import Specialist John Bobel at [email protected].
Sincerely,
(for) Evan Conceicao Designated Official Performing the Duties of the Division Director National Commodity Specialist Division
Ruling history
More rulings on the same tariff codes
RE: First Sale; Multi-Tiered Transactions; Related Parties; Beverage Equipment
RE: Kitchen and household cleaning and maintenance products imported under consignment; Valuation under 19 U.S.C. § 1401a; Computed Value
Re: Affirmation of NY N346051; Applicability of Subheading 9817.00.96, HTSUS, to electric actuators from China
RE: Country of Origin of a Centrifugal Pump
RE: The country of origin of a metal decorative garden stake with light-emitting diode (LED) lights.
RE: The country of origin of a metal decorative garden stake with light-emitting diode (LED) lights
RE: The country of origin of an electric scooter
RE: The country of origin of a battery charger for vehicle batteries
RE: The country of origin of Valsartan and Hydrochlorothiazide Tablets USP, in dosage form
RE: The tariff classification, country of origin and marking of automotive wiring harnesses
Follow N351688
Get an email if this ruling is revoked or modified, or a newer ruling supersedes it.
One email per day at most. Confirm your address once, unsubscribe anytime.
Searching CBP rulings the smart way
Rulings are precedent. See which ones apply to your product: TariffLens semantically searches all 200,000+ CBP rulings and builds defensible classifications backed by ruling citations.