Sodium niobate-based composite energy storage ceramic material

The invention discloses a sodium niobate-based composite energy storage ceramic material and a preparation method thereof. The defect that in the prior art, a sodium niobate-based composite energy storage ceramic material is poor in frequency stability is overcome. The chemical general formula of the material is 0.9 Na < 1-3x > Sm < x > NbO < 3-0.1 > (Sr < 0.6 > Na < 0.2 > Bi < 0.2 >) (Sn < 1-y > Tiy) O < 3 >, in the formula, x is greater than or equal to 0.04 and less than or equal to 0.12, and y is greater than or equal to 0.40 and less than or equal to 0.80. Under the conditions of the environment temperature of 25 DEG C and the electric field frequency of 10 Hz, the effective energy storage density change range of the material is that Wrecc is larger than or equal to 2.45 J/cm < 3 > and smaller than or equal to 4.17 J/cm < 3 >, and the energy storage efficiency change range is that eta is larger than or equal to 72.56% and smaller than or equal to 93.05%; at the environment temperature of 25 DEG C, when a