Potassium-ion　hybrid　capacitors　(PIHCs)　shrewdly　integrate　the　merits　of　the　high　energy　density　of　battery-type　anode　and　the　high　power　density　of　capacitor-type　cathode,　promising　prospects　for　potential　application　in　a　diversity　of　fields.　Here,　we　report　the　synthesis　of　P-doped　porous　carbon　nanosheets　(P-PCNs)　with　favorable　features　as　electrochemical　storage　materials,　including　ultrahigh　specific　surface　area　and　rich　activity　sites.　The　P-PCN　as　Janus　electrodes　show　highly　attractive　electrochemical　properties　of　high　capacity　and　remarkable　stability　for　fast　K+　storage　and　manifest　high　capacitance　for　PF6-　adsorption.　The　P-PCNs　are　applied　as　both　anode　and　cathode　materials　to　set　up　dual-carbon　PIHCs,　which　show　the　capability　to　deliver　a　high　energy/power　density　(165.2　Wh　kg-1　and　5934.4　W　kg-1)　as　well　as　remarkable　long-life　capability.　©　2021　American　Chemical　Society.