Flexible Lead-Free Ba0.5Sr0.5TiO3/0.4BiFeO3-0.6SrTiO3 Dielectric Film Capacitor with High Energy Storage Performance.

Wenwen Wang,Lingchao Lu,Mengjia Fan,Jin Qian,Zhenxiang Cheng,Chaohui Geng,Changhong Yang

doi:10.3390/nano11113065

Abstract

Ferroelectric thin film capacitors have triggered great interest in pulsed power systems because of their high-power density and ultrafast charge–discharge speed, but less attention has been paid to the realization of flexible capacitors for wearable electronics and power systems. In this work, a flexible Ba0.5Sr0.5TiO3/0.4BiFeO3-0.6SrTiO3 thin film capacitor is synthesized on mica substrate. It possesses an energy storage density of Wrec ~ 62 J cm−3, combined with an efficiency of η ~ 74% due to the moderate breakdown strength (3000 kV cm−1) and the strong relaxor behavior. The energy storage performances for the film capacitor are also very stable over a broad temperature range (−50–200 °C) and frequency range (500 Hz–20 kHz). Moreover, the Wrec and η are stabilized after 108 fatigue cycles. Additionally, the superior energy storage capability can be well maintained under a small bending radius (r = 2 mm), or after 104 mechanical bending cycles. These results reveal that the Ba0.5Sr0.5TiO3/0.4BiFeO3-0.6SrTiO3 film capacitors in this work have great potential for use in flexible microenergy storage systems.

Highlights

IntroductionThe energy crisis and environmental pollution have aroused widespread concern
At present, the energy crisis and environmental pollution have aroused widespread concern
The flexible mica substrate coated with bottom electrode was provided for depositing dielectric thin film

Summary

Introduction

The energy crisis and environmental pollution have aroused widespread concern. In order to solve these problems, it is necessary to develop and utilize clean and sustainable energy sources and energy storage devices [1,2,3,4]. At present, advanced energy storage techniques include batteries, superconducting magnetic energy storage systems and electrochemical/dielectric capacitors [5,6]. Dielectric capacitors are attracting immense research interest in pulsed power systems due to their unique features of high-power density (up to 108 W kg−1 ) and short charge−discharge time (10−3 –10−6 s) [7,8,9,10,11,12].

Methods

Results

Conclusion