Breaking the Energy Storage Trade‐off in Antiferroelectrics via Bi 3+ ‐Driven Atomic‐Nanoscale Synergy

ABSTRACT Achieving superior energy storage in antiferroelectric ceramics is limited by a fundamental compromise: realxor behavior comes at the cost of sacrificing polarization strength. This directly leads to a mutually restrictive balance between recoverable energy density ( W rec ) and energy storage efficiency ( η ). To overcome this, we develop a Bi‐induced local bonding modulation strategy in Pb 0.92‐1.5 x Sr 0.08 Bi x Zr 0.49 Sn 0.5 Ti 0.01 O 3 ceramics that simultaneously strengthens the AFE framework and refines polarization response. This approach elevates both the breakdown strength and the AFE‐FE transition field, allowing the material to withstand higher electric fields and release greater stored energy. The optimized composition achieves a record‐high W rec of 15.6 J cm −3 with ∼90% efficiency under 600 kV cm −1 , alongside ultrafast discharge ( t 0.9 ∼64.5 ns) and excellent thermal/frequency stability. Atomic‐scale characterization reveals a coexistence of robust long‐range AFE order and local polar heterogeneity, which collectively smooths the field‐induced transition path and suppresses early breakdown. This work provides a generalizable design principle for dielectric capacitors by strategically decoupling polarization enhancement from relaxor behavior, paving the way for high‐energy, high‐efficiency pulsed‐power systems.