Recently,　dielectric　ceramic　materials　have　been　widely　explored　for　high-power　capacitors　applications.　However,　it　is　still　challenged　for　capacitors　to　enhance　the　energy　density　and　efficiency.　Here,　the　(1-x)　[0.88BaTiO3-0.12Bi(Li0.5Nb0.5)O3]-x(0.8BaTiO3-0.2SrTiO3)　(0.05　＜=　x　＜=　0.20)　ceramics　were　designed　to　improve　both　dielectric　temperature　stability　and　breakdown　strength.　Influence　of　composition　and　phase　structure　on　dielectric　properties　were　studied　in　detail.　Improvement　of　both　dielectric　properties　and　energy　storage　performance　was　achieved　in　this　work.　The　0.95[0.88BaTiO3-0.12Bi(Li0.5Nb0.5)O3]-0.05　(0.8BaTiO3-0.2SrTiO3)　ceramic　shows　the　best　performance,　with　an　energy　storage　density　up　to　2.88　J/cm3　(We　-2.51　J/cm3)　and　a　high　efficiency　-86.81%　under　320　kV/cm.　This　work　not　only　provides　key　materials　for　the　next　generation　of　high-end　energy　storage　capacitors,　but　also　suggests　a　different　route　for　optimizing　the　performance　of　other　relaxor　ferroelectrics.