Two　inorganic-organic　hybrid　polyoxotantalates,　H4[Na(H2O)5]2[CoII(en)3]2{[CoIII(en)]2(Ta6O19)2}·22H2O　(1)　and　H2K2Na6　(H2O)24{[CoIII(en)]2(Ta6O19)2}·33H2O　(2)　have　been　constructed　from　{[CoIII(en)(Ta6O19)]2}10−　({Co2Ta12})　dimers.　Compound　1　has　a　three-dimensional　supramolecular　framework　with　a　pcu-type　topology.　Compound　2　possesses　a　three-dimensional　structure　composed　of　{Co2Ta12}　dimers　and　alkali　metal　ions　(Na+/K+)　via　coordination　bonds.　Polyoxotantalates　1　and　2　have　been　used　as　active　materials　for　ITO/1/Ag　and　ITO/2/Ag　RRAM　devices.　These　devices　exhibit　stable　non-volatile　storage　behavior　and　rewritable　resistive　switching　with　high　ON/OFF　ratios　of　1.43　×　103　and　2.17　×　104　for　1-based　and　2-based　RRAM　devices,　respectively,　and　stable　cyclic　performance　during　100-cycle　stability　tests.　This　discovery　opens　up　new　opportunities　for　the　development　of　electrical　bistability　materials.　©　2024　The　Royal　Society　of　Chemistry.