A　new　type　of　collaborative　extractants　consisting　of　the　ionic　liquid　(IL)　1-aminoprooyl-3-methylimidazolium　bis((trifluoromethyl)sulfonyl)imide,　([APMIM][Tf2N])　and　Cyanex　923　(C923)　is　first　applied　for　selective　extraction　of　valuable　metals　from　spent　lithium-ion　batteries　(LIBs).　The　one-stage　extraction　efficiencies　of　Co2+,　Ni2+　and　Mn2+　are　up　to　99.87　%,　97.74　%,　99.98　%,　respectively,　at　the　optimal　conditions,　and　the　high-purity　Li+　was　enriched　at　the　raffinate.　It　is　found　that　the　extraction　process　follows　the　so-called　“cation　exchange　mechanism”,　and　the　molecular-level　mechanism　is　revealed　via　quantum　chemical　(QC)　calculations.　The　findings　show　that　C923　plays　the　role　of　coordinating　with　metal　ions,　the　cation　of　IL　exchanges　metal　ions　from　the　aqueous　to　organic　phases,　and　the　anion　[Tf2N]-　of　IL　can　stabilize　the　complex　species　of　metal　ion-[Tf2N]--C923　in　organic　phase.　This　work　provides　new　insights　for　the　design　of　novel　IL-based　extractants　for　the　recycling　of　spent　LIBs.　©　2024