Battery-type　faradaic　materials　are　considered　a　class　of　promising　electrodes　for　capacitive　deionization　(CDI)　due　to　their　superior　ability　to　store　ions　through　redox　reactions.　However,　the　desalination　potential　of　such　electrode　materials　has　not　been　fully　explored　subject　to　the　accessibility,　conductivity,　stability,　etc.　Herein,　embedded　battery　material　Ag　nanoparticles　is　designed　in　capsule-structural　units　composed　of　graphene　and　constructed　freestanding　composite　electrodes　for　CDI.　Particularly,　these　Ag　nanoparticles　confined　in　interconnected　graphene　capsules　can　be　both　efficiently　accessed　by　the　electrolyte　and　rationally　protected　by　the　capsule　networks,　significantly　unlocking　their　potential　as　desalination　materials.　Impressively,　the　optimized　Ag-involved　anodes　can　achieve　an　ultrahigh　NaCl　desalination　capacity　of　approximate　to　360　mg　g-1　(approximate　to　218　mg　g-1　for　Cl-)　at　1.4　V　and　exhibit　good　cycling　stability.　Moreover,　the　as-designed　anodes　also　have　very　competitive　desalination　capacities　for　other　anions,　such　as　SO2-　4　(approximate　to　90　mg　g-1)　and　CrO2-　4　(approximate　to　77　mg　g-1),　suggesting　the　broad　applicability　of　such　Ag-involved　electrodes.　This　work　shows　that　the　ingenious　introduction　of　space-confined　structures　is　an　effective　means　of　unlocking　the　desalination　potential　of　Ag-based　materials,　opening　up　alternative　avenues　for　the　development　of　other　high-performance　battery-type　desalination　electrodes.