Bismuth strontium titanate-based lead-free ceramic material for efficient capacitor and preparation method of ceramic material

The invention relates to a bismuth strontium titanate-based lead-free ceramic material for a high-efficiency capacitor and a preparation method of the ceramic material, and belongs to the field of electric energy storage materials. A solid-phase synthesis method is adopted, on the basis of a relaxor ferroelectric material Sr0.7Bi0.2TiO3, Nb and Ni heterovalent elements in a certain molar ratio are doped into the B site of a perovskite structure to increase the charge disorder of the perovskite structure, the novel composite ceramic is obtained, the chemical formula of the novel composite ceramic is (1-x)Sr0.7Bi0.2TiO3-xBi(Ni2/3Nb1/3)O3, and x is larger than or equal to 0 and smaller than or equal to 0.15. The main performance parameters of the energy storage ceramic material obtained by the invention can recover the energy storage density Wrec which reaches 4.19-5.98 J/cm , and the energy storage efficiency eta reaches up to 92.6-98.6%. The method is simple in technological process, suitable for industrial pr