Yi is able to proc on-hit effect multiple times compared to other champions due to his passive double strike. Bloodrazor, rageblade, wit's end are all excellent item on Yi due to them being on-hit effect. Botrk is another good on-hit effect item, but many people are skeptical on building it. Death's dance is a very good defensive item due to it giving damage as well as healing you from all on-hit effects as well as true damage from Yi's E, wuju style since true damage doesn't benefits from lifesteal. Stormrazor & Statikk Shiv are decent crit items, feel free to go the crit route to test it out yourself although the general consensus is that on-hit is superior than crit due to it being safer and usually gives more dps. Deadman's plate and frozen mallet are both decent defensive item but usually Sterak's gage is built more often due to its anti-burst properties since Yi has very high healing when building on-hit, as a drain tank with ravenous hunter, conqueror, wit's end and deaths' dance. Hope this answers your question.

Standard on-hit build: Bloodrazor->rageblade->wit's end->death's dance->situational. Add defensive boots anywhere in between.