Here the printer’s manuscript reads bond while the 1830 edition has band. There is considerable evidence that scribe 2 of 𝓟 tended to mix up the letters a and o, but then so did Oliver Cowdery (here the probable scribe in 𝓞) and the 1830 typesetter. (See the discussion regarding the name Ammaron under 4 Nephi 1:47 for evidence that all three of these tended to mix up the letters a and o.)
Elsewhere the Book of Mormon text definitely prefers “band(s) of death” over “bond(s) of death”: there are 13 instances of “the bands of death”—and without any textual variation between bands and bonds. So band is probably correct here in Mormon 9:13. Nonetheless, it should be pointed out that there is a difference: in Mormon 9:13 we have the only instance of the singular band in referring to “band(s) of death”. Even so, this uniqueness in grammatical number holds also for “this eternal bond of death”. In accord with usage elsewhere in the text, the critical text will follow the 1830 reading, “this eternal band of death”. For further discussion of the competition between band(s) and bond(s), see under Mosiah 23:12–13.
Summary: Maintain in Mormon 9:13 the use of band, the 1830 reading, instead of bond, the reading in 𝓟; usage elsewhere in the text consistently refers to “the bands of death”.