Fatigue resistant lead-free multilayer ceramic capacitors with ultrahigh energy density

摘要

The critical role of electrical homogeneity in optimising electric-field breakdown strength (BDS) and energy storage in high energy density (0.7 -x)BiFeO3-0.3BaTiO(3)-xBi(Li0.5Nb0.5)O-3(BF-BT-xBLN) lead-free capacitors is demonstrated. The high BDS for bulk ceramics and multilayers (dielectric layer thickness similar to 8 mu m) of similar to 260 and similar to 950 kV cm(-1), respectively, gives rise to record-performance of recoverable energy density,W-rec= 13.8 J cm(-3)and efficiency,eta= 81%. Under an electric field of 400 kV cm(-1), multilayers are temperature stable up to 100 degrees C, frequency independent in the range 10(-2)to 10(2)Hz, have low strain (<0.03%) and are fatigue-resistant up to 10(4)cycles (W(rec)variation < 10%). These properties show promise for practical use in pulsed power systems.