To be clear, these ships aren't victims of a battle; instead, the U.S. Navy intentionally scuttled them at the location in 1945 after taking the island in an attempt to create an artificial breakwater for a planned harbor. Several of them are reinforced concrete barges, ships built to support naval operations and not necessarily for any direct combat role. Four of them are former cargo vessels, at least one of which is Japanese according to naval documents.
Below, you can see contemporaneous documents detailing the layout of the breakwater. When these documents were published and these photos were taken, the structure had yet to be completed.
Thanks to research by maritime history enthusiast Erlend Bonderud, we know the identities of the four non-concrete ships used to form the north and south ends of the small artificial harbor. They are the IJN Toyotu Maru, the Chetvertyi Krabalov, the Caliche, and the Gilyak. The Toyotu Maru was a former Imperial Japanese Navy craft, presumably seized by the Americans.
The three other boats were previously lent to the USSR and served a variety of purposes before being taken back by the U.S. Navy and utilized in the project on Iwo Jima. The rest are concrete barges of various types.
We're able to confirm that several ships are reinforced concrete barges not only because of up-close photography that reveals their composition, but also
because of archival records and first-hand accounts from operations on the island during the war. In a
digitized portion of his book
In Search of Angels, the late Staff Sergeant Arvin S. Gibson reported that On March 17, 1945, the Seabees (Naval Construction Battalions) were going to "sink some old concrete ships out from the beach to provide a breakwater for our DUKW operations," a DUKW being a popular type of light amphibious vehicle used for marine landings. They had trouble in rough ocean waters, and a breakwater would've made landing them much easier.
Likewise, it's stated
in this source from the National Archives that on June 13th, 1945, the final leg of the breakwater was completed when "Concrete Barge #30 [was] sunk in modified position Love... thus completing all three legs of the Iwo Jima Blockship Breakwater." However, a typhoon blew through in short order and severely damaged the structure being built around them. The project was abandoned as a result.