Aqueous Zn-ion batteries (ZIBs) are regarded as alternatives to Li-ion batteries benefiting from both improved safety and environmental impact. The widespread application of ZIBs,h owever,i sc ompromised by the lacko fh ighperformance cathodes.Currently,only the intercalation mechanism is widely reported in aqueous ZIBs,whichsignificantly limits cathode options.B eyond Zn-ion intercalation, we comprehensively study the conversion mechanism for Zn 2+ storage and its diffusion pathway in aCuI cathode,indicating that CuI occurs ad irect conversion reaction without Zn 2+ intercalation due to the high energy barrier for Zn 2+ intercalation and migration. Importantly,t his direct conversion reaction mechanism can be readily generalized to other highcapacity cathodes,s uch as Cu 2 S( 336.7 mA hg À1 )a nd Cu 2 O (374.5 mA hg À1 ), indicating its practical universality.Our work enriches the Zn-ion storage mechanisma nd significantly broadens the cathode horizons towards next-generation ZIBs.