Energy storage performances regulated by BiMnO₃ proportion in limited solid solution films

Na_0.5Bi_0.5TiO₃–BiMnO₃ (NBT–BM) limited solid solution films were fabricated to investigate the lattice modification on the energy storage performances. The introduction of the BM solute lattice induces the NBT solvent lattices undergoing the transition from the pure phase, solid solution, solubility limit to precipitation. Correspondingly, the polarization states transfer from the macroscopic ferroelectric domains to nanodomains then to compound ferroelectric domains. The introduction of BiMnO₃ generates great lattice changes including the local lattice fluctuation and the large lattice stretching, which enhance the energy storage performances, with the energy storage efficiency being enhanced from 39.2% to 53.2% and 51.7% and the energy density being enhanced from 33.1 J/cm³ to 76.5 J/cm³ and 83.8 J/cm³ for the BM components of 2% and 4%, respectively. The lattice modifications play a key role in the energy storage performances for limited solid solution films, which provides an alternative strategy for energy storage material.