Multilayer Lead-Free Ceramic Capacitors with Ultrahigh Energy Density and Efficiency

Jinglei Li; Fei Li; Zhuo Xu; Shujun Zhang

doi:10.1002/adma.201802155

Multilayer Lead-Free Ceramic Capacitors with Ultrahigh Energy Density and Efficiency

Adv Mater. 2018 Aug;30(32):e1802155. doi: 10.1002/adma.201802155. Epub 2018 Jun 26.

Authors

Jinglei Li^{1

2}, Fei Li¹, Zhuo Xu¹, Shujun Zhang³

Affiliations

¹ Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
² School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
³ Institute for Superconducting and Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, NSW, 2500, Australia.

PMID: 29944176
DOI: 10.1002/adma.201802155

Abstract

The utilization of antiferroelectric (AFE) materials is thought to be an effective approach to enhance the energy density of dielectric capacitors. However, the high energy dissipation and inferior reliability that are associated with the antiferroelectric-ferroelectric phase transition are the main issues that restrict the applications of antiferroelectric ceramics. Here, simultaneously achieving high energy density and efficiency in a dielectric ceramic is proposed by combining antiferroelectric and relaxor features. Based on this concept, a lead-free dielectric (Na_0.5 Bi_0.5 )TiO₃ -x(Sr_0.7 Bi_0.2 )TiO₃ (NBT-xSBT) system is investigated and the corresponding multilayer ceramic capacitors (MLCCs) are fabricated. A record-high energy density of 9.5 J cm^-3 , together with a high energy efficiency of 92%, is achieved in NBT-0.45SBT multilayer ceramic capacitors, which consist of ten dielectric layers with the single-layer thickness of 20 µm and the internal electrode area of 6.25 mm² . Furthermore, the newly developed capacitor exhibits a wide temperature usage range of -60 to 120 °C, with an energy-density variation of less than 10%, and satisfactory cycling reliability, with degradation of less than 8% over 10⁶ cycles. These characteristics demonstrate that the NBT-0.45SBT multilayer ceramic is a promising candidate for high-power energy storage applications.

Keywords: energy storage; lead-free antiferroelectric; multilayer ceramic capacitors.