Multi-Polar Order Engineering Enables Near-Ideal Efficiency in Lead-Free Energy Storage Perovskite

Toxic lead-based dielectrics dominate high-performance capacitors, creating urgent environmental and supply-chain challenges. Multi-polar order engineering is deployed to create an industrially scalable lead-free perovskite achieving simultaneous record efficiency (η ≈ 95%) and energy density (12 J cm^-3). Phase-field simulations are also used to guide micro-to-nano domain design to construct switchable polar nano region that delay polarization saturation. Crucially, sub-angstrom electronic state optimization - previously unexplored in energy storage dielectrics - is revealed as pivotal: synchrotron XAS quantifies Nb-O dipole ionicity enhancement via electronic polarization, while atomic-resolution electron microscopy statistically confirms bond-length homogenization and distortion reduction that structurally anchor this effect. This hierarchical atomic-to-electronic control reshapes the electrical microstructure, enabling unified charge dynamics (validated by DRT analysis) that deliver ultrafast field response (<32 ns discharge) and exceptional thermal resilience (< ±4% current fluctuation, 25-150 °C). Fabricated from commodity precursors, the material eliminates the reliance on rare-earth precursors that are common in PLZT production, significantly lowering costs while mitigating environmental impacts. Overall, this work establishes a sustainable pathway for grid-scale power electronics.