Reviving　lithium　metal　anode　is　of　great　significance　to　developing　high-energy-density　batteries　after　addressing　the　lithium　dendrite.　Constructing　functional　separator　with　charged　nanochannel　configuration　has　been　proven　to　be　an　effective　way　to　inhibit　nucleation　of　lithium　dendrites　due　to　the　achievement　of　a　fast　and　selective　lithium　ion　transport.　While　the　ion　regulation　capability　of　existing　functional　separators　cannot　be　maximized　because　their　nanochannels　are　much　larger　than　the　electric　double　layer　(EDL)　regions　that　dominate　ion　transport.　Considering　the　tiny　EDL　thickness　(∼1　nm)　formed　in　the　electrolyte,　the　sulfonate-rich　covalent　organic　framework　(COF)　is　developed　as　functional　separator　to　achieve　a　dependable　ion　regulation　based　on　the　nano-confined　channel　(∼1.55　nm)　and　surface　negative　charges.　Consequently,　a　high　Li+　transference　number　tLi+　(0.85)　and　sufficient　ionic　conductivity　(0.53　mS　cm−1)　are　obtained　simultaneously,　which　effectively　alleviates　dendrite　nucleation　and　growth　of　lithium　metal　anode　for　over　1000　h.　Moreover,　the　principle　for　fast　and　selective　lithium-ion　transport　is　revealed　from　a　new　perspective　of　EDL　region　embedded　in　the　nanochannel.　Overall,　this　work　demonstrates　a　strategy　to　eliminate　lithium　dendrites　via　ion　regulation　of　charged　nanochannels,　which　is　anticipated　to　promote　the　practical　application　of　lithium　metal　batteries.　©　2024