Metallic　zinc　is　an　excellent　anode　material　for　Zn-ion　batteries,　but　the　growth　of　Zn　dendrite　severely　hinders　its　practical　application.　Herein,　an　efficient　and　economical　cationic　additive,　poly　dimethyl　diallyl　ammonium　(PDDA)　was　reported,　used　in　aqueous　Zn-ion　batteries　electrolyte　for　stabilizing　Zn　anode.　The　growth　of　zinc　dendrites　can　be　significantly　restrained　by　benefiting　from　the　pronounced　electrostatic　shielding　effect　from　PDDA　on　the　Zn　metal　surface.　Moreover,　the　PDDA　is　preferentially　absorbed　on　Zn　(002)　plane,　thus　preventing　unwanted　side　reactions　on　Zn　anode.　Owing　to　the　introduction　of　a　certain　amount　of　PDDA　additive　into　the　common　ZnSO4-based　electrolyte,　the　cycle　life　of　assembled　Zn　parallel　to　Zn　cells　(1　mA.cm(-2)　and　1　mAh.cm(-2))　is　prolonged　to　more　than　1100　h.　In　response　to　the　perforation　issue　of　Zn　electrodes　caused　by　PDDA　additives,　the　problem　can　be　solved　by　combining　foamy　copper　with　zinc　foil.　For　real　application,　Zn-ion　hybrid　supercapacitors　and　MnO2　parallel　to　Zn　cells　were　assembled,　which　exhibited　excellent　cycling　stability　with　PDDA　additives.　This　work　provides　a　new　solution　and　perspective　to　cope　with　the　dendrite　growth　problem　of　Zn　anode.