Adding an IV to an AES implementation
AES is  a block cipher which actually only "maps" (encrypt) a 128 bit block (plainblock) to a 128 bit block (cipherblock) and vice versa. This "mapping" is key dependent.

To encrypt some data you normally apply an encryption mode like CBC, CTR, GCM etc. using e.g. AES as block cipher within this mode. These modes normally require an IV or Nonce.

So, not the actually AES requires an IV but the mode used to actually en-/decrypt data.