To　develop　a　new　type　of　energetic　ionic　liquid　(EIL)　that　has　a　catalytic　effect　on　the　thermal　decomposition　of　ammonium　perchlorate　(AP)　and　can　be　ignited　in　white　fuming　nitric　acid　(WFNA),　six　borane-containing　ionic　liquids　based　on　biferrocene　were　successfully　synthesized,　and　their　structures　were　determined　by　x-ray　crystallography.　Except　for　iodized　salts,　four　EILs　with　high　thermal　stability　burned　rapidly　in　WFNA,　one　of　which,　bis[1-(ferrocenylmethyl)imidazole-3-yl]　dihydroboronium　cyanoborohydride,　[Fcmim][BH3CN],　produced　the　shortest　ignition　delay　(ID)　time　of　5 ms.　However,　iodized　salts　demonstrated　a　better　catalytic　effect　on　AP　than　did　BH3CN−-　or　N(CN)2−-based　EILs　and　bis[1-(ferrocenylmethyl)benzimidazole-3-yl]　dihydroboronium　iodide,　[Fcbemim][I],　could　advance　the　final　thermal　decomposition　temperature　of　AP　by　50°C.　Anions　have　a　significant　effect　on　the　structures　and　performances　of　ionic　liquids.　©　2021　John　Wiley　&　Sons,　Ltd.