Transition-metal　sulfides　(TMSs)　and　transition-metal　phosphites　(TMPOs)　have　been　recommended　for　promising　electrocatalytic　materials　used　for　supercapacitors　(SCs)　and　water　splitting.　Nevertheless,　the　application　of　only　TMSs　or　TMPOs　is　limited　due　to　their　slow　reaction　kinetics　and　drastic　volume　expansion　during　electrochemical　processes.　Designing　a　stable　structure　by　combining　TMSs　with　TMPOs　was　expected　to　improve　their　performance.　A　Zn-Ni-S/Ni-Co-P　(ZNS/NCP)　composite　was　synthesized　by　a　hydrothermal　method.　SEM,　XRD,　XPS,　BET,　and　electrochemical　tests　were　used　to　study　the　morphologies,　phases,　capacitive　performance,　and　electrocatalytic　activities.　It　is　shown　that　ZNS/NCP　composites　were　composed　of　NiS33.3Zn32.3,　Co11(HPO3)8(OH)6,　and　Ni11(HPO3)8(OH)6with　a　microsphere　structure,　were　closely　bound　with　nickel　substrates,　and　had　a　large　specific　surface　area,　which　can　provide　abundant　active　sites　and　shorten　the　electron/ion　diffusion　distance.　The　specific　capacitance　of　the　ZNS/NCP　electrode　was　6.94F/cm2at　8　mA/cm2and　had　an　excellent　cycle　stability.　The　asymmetric　supercapacitor　assembled　with　Fe2O3-IrO2as　an　anode　and　ZNS/NCP　as　a　cathode　had　a　power　density　of　5.95　mW/cm2,　with　an　energy　density　of　0.52　mWh/cm2.　It　also　had　an　excellent　stability.　The　overpotential　values　of　ZNS/NCP,　ZNS,　NCP,　and　NF　were　126,　185,　154,　and　324　mV　for　HER　and　230,　270,　330,　and　470　mV　for　OER　at　10　mA/cm2,　respectively.　If　the　ZNS/NCP　electrode　was　used　both　as　a　cathode　and　anode　for　water　splitting,　an　excellent　performance　could　be　obtained.　The　required　voltages　for　ZNS/NCP||ZNS/NCP,　ZNS||ZNS,　NCP||NCP,　and　NF||NF　were　1.46,　1.68,　1.66,　and　1.81　V　at　10　mA/cm2,　respectively.　©　2023　American　Chemical　Society.　All　rights　reserved.