Lead-free　dielectric　capacitors　for　energy　storage　device　have　attracted　increasing　attention　recently　because　of　their　high-power　density　and　superior　temperature　stability.　In　this　work,　Nd-doped　silver　niobate　(AgNbO3,　abbreviated　as　AN)　lead-free　antiferroelectric　ceramics　were　prepared　by　utilizing　traditional　solid　state　reaction　method.　A　large　energy　storage　density　of　4.6　J/cm3　and　an　efficiency　of　62.5%　were　simultaneously　obtained　in　the　1%　Nd-doped　AN　sample　with　an　outstanding　power　density　of　54.0　MW/cm3　and　an　ultrafast　discharge　speed　(t0.9)　of　59.2　ns.　Additionally,　the　1%　Nd-doped　AN　ceramic　demonstrates　a　good　temperature　stability　from　25　degrees　C　to　130　degrees　C.　The　excellent　energy　storage　properties　of　the　1%　Nd-doped　ceramic　is　ascribed　to　the　enhanced　breakdown　electric　field　induced　by　grain　size　engineering　and　the　construction　of　phase　structure　via　heterovalent　substitution　at　the　A-site　of　the　lattice　structure　at　room　temperature.　Our　present　work　suggests　that　the　1%　Nd-doped　AN　ceramic　show　promise　for　energy　storage　application　in　miniaturized　mobile　electronic　devices　and　high-power　equipment.　(c)　2021　Elsevier　B.V.　All　rights　reserved.