Is The Lithium Cell or Battery UN Tested?

Except for prototype batteries, each lithium cell or battery must be of the type proven to meet the criteria in part III, sub-section 38.3 of the UN Manual of Tests and Criteria. Lithium cells and batteries are subject to these tests regardless of whether the cells used to construct the battery are of a tested type. Refer to 49 CFR 173.185 (a)

The SDS or battery manufacturer should be able to confirm that the battery has been tested in accordance to  38.3 of the UN Manual of Tests and Criteria.   If you are a battery manufacturer you can download the test guide here.