In:
Advanced Materials, Wiley, Vol. 35, No. 22 ( 2023-06)
Abstract:
Dielectric capacitors are promising for high power energy storage, but their breakdown strength ( E b ) and energy density ( U e ) usually degrade rapidly at high temperatures. Adding boron nitride (BN) nanosheets can improve the E b and high‐temperature endurance but with a limited U e due to its low dielectric constant. Here, freestanding single‐crystalline BaZr 0.2 Ti 0.8 O 3 (BZT) membranes with high dielectric constant are fabricated, and introduced into BN doped polyetherimide (PEI) to obtain laminated PEI–BN/BZT/PEI–BN composites. At room temperature, the composite shows a maximum U e of 17.94 J cm −3 at 730 MV m −1 , which is more than two times the pure PEI. Particularly, the composites exhibit excellent dielectric‐temperature stability between 25 and 150 °C. An outstanding U e = 7.90 J cm −3 is obtained at a relatively large electric field of 650 MV m −1 under 150 °C, which is superior to the most high‐temperature dielectric capacitors reported so far. Phase‐field simulation reveals that the depolarization electric field generated at the BZT/PEI–BN interfaces can effectively reduce carrier mobility, leading to the remarkable enhancement of the E b and U e over a wide temperature range. This work provides a promising and scalable route to develop sandwich‐structured composites with prominent energy storage performances for high‐temperature capacitive applications.
Type of Medium:
Online Resource
ISSN:
0935-9648
,
1521-4095
DOI:
10.1002/adma.202300962
Language:
English
Publisher:
Wiley
Publication Date:
2023
detail.hit.zdb_id:
1474949-X
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