The USA does not have a Free Trade Agreement (FTA) with the DRC,...

The USA does not have a Free Trade Agreement (FTA) with the DRC, nor a regional agreement that includes the DRC, so a CATL battery plant located in the DRC will not be eligible for preferential treatment.
However, China is currently in negotiations with the DRC.

Prior to 2000, the US had only three comprehensive FTAs: Canada, Israel and Mexico.
Since 2000, the US has concluded FTAs with Australia, Bahrain, Chile, Colombia, Jordan, Korea, Oman, Morocco, Singapore, Panama, Peru and the six Central American parties to CAFTA (Costa Rica, Dominican Republic, El Salvador, Guatemala, Honduras and Nicaragua). The agreements with Colombia, Korea, Oman and Panama are still pending ratification.
In addition, a stepping-stone agreement on trade and investment, short of a full FTA, has been signed with the five members of the Southern Africa Customs Union (Botswana, Lesotho, Namibia, South Africa and Swaziland). The US is also in stalled FTA negotiations with Malaysia, Thailand and the United Arab Emirates.Countries reportedly on Washington’s "radar screen" for a bilateral FTA since some time include: Algeria, Egypt, Tunisia, Saudi Arabia and Qatar.
(Ref: https://www.bilaterals.org)

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