Sterically　hindered　(S)-1,1＇-binaphthyl-2,2＇-diol　had　been　successfully　copolymerized　with　4,4＇-sulfonyldiphenol　and　4,4＇-difluorobenzophenone　to　yield　fibrous　poly(arylene　ether　ketone)s　(PAEKs)　containing　various　amounts　of　binaphthyl　unit,　which　was　then　selectively　and　efficiently　sulfonated　using　ClSO3H　to　yield　sulfonated　poly(arylene　ether　ketone)s　(SPAEKs)　with　ion　exchange　capacities　(IECs)　ranging　from　1.40　to　1.89　mmol·g-1.　The　chemical　structures　of　the　polymers　were　confirmed　by　2D　1H-1H　COSY　NMR　and　FT-IR.　The　thermal　properties,　water　uptake,　swelling　ratio,　proton　conductivity,　oxidative　stability　and　mechanical　properties　of　SPAEKs　were　investigated　in　detail.　It　was　found　that　the　conjugated　but　non-coplanar　structure　of　binaphthyl　unit　endorsed　excellent　solubility　and　film-forming　capability　to　SPAEKs.　The　SPAEK-50　with　an　IEC　of　1.89　mmol·g-1　exhibited　a　proton　conductivity　of　102　mS·cm-1　at　30　°C,　much　higher　than　that　of　the　state-of-the-art　Nafion　N212　membrane　and　those　of　many　previously　reported　aromatic　analogs,　which　may　be　attributed　to　the　likely　large　intrinsic　free　volume　of　SPAEKs　created　by　the　highly　twisted　chain　structures　and　the　desirable　microscopic　morphology.　Along　with　the　remarkable　water　affinity,　thermal　stabilities　and　mechanical　properties,　the　SPAEKs　were　demonstrated　to　be　promising　proton　exchange　membrane　(PEM)　candidates　for　potential　membrane　separations.　©　2018　by　the　authors.