A-ceramics Anisotropic shapes Breakdown field Core-shell Core-shell particle Effective Medium Approximation Electrical energy External electric field Hybrid supercapacitors Internal electric fields Landau potential Maximum density Nano ceramics Numerical calculation Numerical minimization Quantitative evaluation Super capacitor Theoretical approach Anisotropy Ceramic materials Dielectric materials Electric fields Electrolytic capacitors Ferroelectric ceramics Laplace equation Permittivity Polarization Shells (structures)