The　anion　conductivity　is　one　of　the　key　properties　of　anion　exchange　membranes　(AEMs),　which　is　affected　by　the　content　and　distribution　of　ionic　groups　in　the　ionomers.　Herein,　a　series　of　poly(fluorenyl　ether　ketone)s　with　multiple　phenylmethyl　groups　were　synthesized.　After　bromination,　the　phenylmethyl　groups　were　attached　with　linear　tri-　and　di-quaternary　ammonium　side　chains.　As　a　result,　the　quaternary　ammonium　groups　were　tethered　closely　at　the　aliphatic　side　chains　which　emanate　from　the　specific　segments　of　the　aromatic　backbone.　The　ion　exchange　capacity,　water　affinity,　Br−　conductivity,　morphology,　thermal　property,　mechanical　property,　oxidative　stability,　and　VO2+　permeability　of　the　obtained　AEMs　were　studied.　It　has　been　found　that　both　types　of　AEMs　have　well-developed　hydrophilic-hydrophobic　phase　separation.　When　comparing　at　similar　ion　exchange　capacity　(IEC),　the　AEMs　bearing　tri-quaternary　ammonium　side　chains　have　higher　Br−　conductivity　than　the　AEMs　bearing　di-quaternary　ammonium　side　chains,　presumably　because　of　the　better　phase　separation　in　the　former.　All　of　the　AEMs　have　significantly　reduced　VO2+　permeability　than　Nafion　212,　owing　to　the　positive　effect　of　Donnan　repulsion.　Along　with　the　other　characterizations,　the　obtained　AEMs　were　proven　to　be　promising　candidates　for　potential　vanadium　redox　flow　battery　applications.　©　2021　Elsevier　B.V.