The　transformation　of　Li2S2　-Li2S　is　indubitably　the　most　crucial　and　labored　rate　-limiting　step　among　the　sophisticated　reactions　for　the　lithium　-sulfur　batteries　(LSBs),　the　adjustment　of　which　is　anticipated　to　impede　the　shuttle　effect.　Herein,　a　N,　Se　dual　-doped　carbon　nanocages　embedded　by　Co-CoSe2　nanoparticles　(Co-CoSe2　@NSeC)　is　employed　as　a　functional　coating　layer　on　commercial　separator　to　improve　the　performance　of　LSBs.　The　well　-designed　N,　Se　co　-doped　nanostructures　endow　the　modified　layer　with　a　satisfactory　capacity　for　blocking　polysulfides.　Both　calculations　and　experiments　jointly　disclose　that　the　Li2S2　to　Li2S　reaction,　including　the　liquid　-solid　conversion,　was　prominently　expedited　both　thermodynamically　and　electrodynamically.　Consequently,　the　batteries　fabricated　with　Co-CoSe2　@NSeC　modified　separator　can　deliver　a　favorable　764.2　mAh　g-1　with　8.0　C,　accompanied　by　a　salient　long　cycling　lifespan　(only　0.066　%　at　1　C　and　0.061　%　under　2　C　after　10　0　0　and　20　0　0　cycles),　and　a　desired　anode　protection.　In　addition,　despite　a　raised　areal　loading　of　7.53　mg　cm-2　was　introduced,　the　cells　assembled　by　Co-CoSe2　@NSeC@PP　are　allowed　to　produce　an　outstanding　initial　behavior　of　8.71　mAh　cm-2　under　0.2　C.　This　work　may　reinforce　further　explorations　and　serve　with　valuable　insights　into　N,　Se　dual　-doping　materials　for　high-performance　LSBs.　(c)　2024　Published　by　Elsevier　Ltd　on　behalf　of　The　editorial　office　of　Journal　of　Materials　Science　&　Technology.