Transition-metal　selenides　have　recently　attracted　increasing　interest　in　supercapacitors　(SCs)　owning　to　their　fascinating　electrochemical　properties.　Here,　binary　metal　selenides　(NiCoSe2,　NiCo2Se4,　NiCo2Se4)　are　designed　as　novel　electrode　materials　according　to　the　reported　NiSe　and　CoSe　via　a　one-step　electrodeposition　process.　The　effects　of　different　Ni/Co　ratio　on　pseudo-capacitive　properties　of　the　binary　metal　selenides　are　investigated　accordingly.　Obviously,　the　designed　binary　metal　selenides　can　combine　the　advantages　of　both　metal　selenides.　As　a　result,　the　NiCoSe2　sample　exhibits　an　optimized　performance　with　a　high　specific　capacity　(334.2　mAh　g–1,　1　A　g–1),　good　rate　capability,　and　excellent　durability　(90.7%,　5000　cycles).　Most　notably,　the　NiCoSe2//AC　asymmetric　SC　(ASC)　exhibits　an　excellent　energy　density　of　41.7　Wh　kg–1　at　800　W　kg–1.　Hence,　a　variety　of　ions　with　complementary　advantages　can　be　combined　by　electrodeposition,　which　provides　an　efficient　way　to　synthesize　excellent　materials　with　various　properties.　©　2021　Institute　of　Physics　Publishing.　All　rights　reserved.