Near‐Zero Energy Consumption Capacitors by Controlling Inhomogeneous Polarization Configuration

Abstract Taking into account the need for energy conservation, achieving near‐zero energy loss, namely ultrahigh efficiency ( η ), in energy storage capacitors with large recoverable energy storage density ( W rec ) plays an important role in applications, which is one of the major challenges in dielectric energy storage field. Here, guided by phase‐field simulation, inhomogeneous polarization configuration with multiple symmetries and polarization magnitudes is controlled through aliovalent strongly polar double ion design to establish a strongly disordered state. A record‐high η of ≈97.4% is realized in lead‐free relaxors with a large W rec of ≈8.6 J cm −3 , which also give a giant W rec of ≈11.6 J cm −3 with an ultrahigh η of ≈96.1% through high‐energy ball milling, showing a breakthrough progress in ceramic capacitors with a maximum figure of merit of 330. This work demonstrates that controlling inhomogeneous polarization configuration is an effective avenue to develop new high‐performance near‐zero energy loss energy storage capacitors.