Gradient‐Structured Ceramics with High Energy Storage Performance and Excellent Stability

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2023-02, Vol.19 (6), p.e2206125-n/a
• Main Authors: Yan, Fei, Ge, Guanglong, Qian, Jin, Lin, Jinfeng, Chen, Chukai, Liu, Zhifu, Zhai, Jiwei
• Format: Article
• Language: English
• Subjects: Bi 0.5Na 0.5TiO 3; Ceramics; Efficiency; Electric fields; Energy storage; gradient structures; lead‐free ceramics; Nanotechnology; Polarization; stability
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202206125

Owing to the high power density, eco‐friendly, and outstanding stability, the lead‐free ceramics have attracted great interest in the fields of pulsed power systems. Nevertheless, the low energy storage density of such ceramics is undoubtedly a severe problem in practical applications. To overcome this limitation, the lead‐free ceramics with gradient structures are designed and fabricated using the tape‐casting method herein. By optimizing the composition and distribution of the gradient‐structured ceramics, the energy storage density, and efficiency can be improved simultaneously. Under a moderate electric field of 320 kV cm−1, the value of recoverable energy storage density (Wrec) is higher than 4 J cm−3, and the energy storage efficiency (η) is of ≥88% for 20‐5‐20 and 20‐10‐20. Furthermore, the gradient‐structured ceramics of 20‐10‐0‐10‐20 and 20‐15‐0‐15‐20 possess high applied electric field, large maximum polarization, and small remnant polarization, which give rise to ultrahigh Wrec and η on the order of ≈6.5 J cm−3 and 89–90%, respectively. In addition, the energy storage density and efficiency also exhibit excellent stability over a broad range of frequencies, temperatures, and cycling numbers. This work provides an effective strategy for improving the energy storage capability of eco‐friendly ceramics. The lead‐free ceramics with gradient structure are designed and prepared by the tape‐casting method. After optimizing the composition and distribution of the gradient‐structured ceramics, giving rise to slim P–E loops, large Pmax and high energy storage performance (Wrec > 6.5 J cm−3 and η ≥ 89%) along with excellent stability.