Effect of Ultrasonic Excitation on Discharge Performance of a Button Zinc-Air Battery.

Zhao Luo,Junhui Hu,Qiang Tang

doi:10.3390/mi12070792

Abstract

In this paper, a method to increase the output power of a button zinc–air battery by applying acoustofluidics induced by ultrasonic excitation to the battery is proposed and demonstrated. In the structural design of the device, a flat piezoelectric ring was bonded onto the top of the outer surface of the cathode shell to excite an ultrasonic field in the battery. The maximum output power of the zinc–air battery increased by 46.8% when the vibration velocity and working frequency were 52.8 mm/s (the corresponding vibration amplitude was 277 nm) and 161.2 kHz and the rating capacity increased by about 20% with the assistance of the acoustofluidic field induced by ultrasonic excitation. Further analyses indicated that the discharge performance improvement can be attributed to the acoustic microstreaming vortices and the decrease of the viscosity coefficient in the electrolyte solution, which were both caused by ultrasonic excitation of the piezoelectric ring.

Highlights

Owing to the merits such as high energy density (1086 W·h/kg in theory), ecofriendliness, low cost, and high safety [1,2,3], zinc–air batteries have garnered extensive interest in the energy engineering field over recent years
With the development of zinc–air battery performance, the primary zinc–air batteries have been commercially implemented for some applications such as hearing-aids and outdoor lighting [6,31,32]
The analyses showed that the ultrasonic effects in electrolyte solution, such as acoustic microstreaming vortices and viscosity decrease, contribute to the discharge performance improvement by enhancing the uniformity of OH− distribution and decreasing the resistance of mass transfer [37,39]

Summary

Introduction

Owing to the merits such as high energy density (1086 W·h/kg in theory), ecofriendliness, low cost, and high safety [1,2,3], zinc–air batteries have garnered extensive interest in the energy engineering field over recent years. The abbreviation vp-p in the figure is the averaged peak–peak value of the out-of-plane vibration velocity on the upper surface of the piezoelectric ring, which was measured by the 3D laser Doppler vibrometer. Considering the propagation of the ultrasonic field into the inner cavity of the battery, the weakening of both concentration polarization and electric double layer effect can be attributed to the acoustic microstreaming vortices and viscosity decrease the electrolyte solution induced by the acoustolow-frequency range inofa Bode plot is mainly caused by the concentration polarization and fluidic field [40,42]. Considering the propagation of the ultrasonic field into the inner cavity of the battery, the weakening of both concentration polarization and electric double layer effect can be attributed to the acoustic microstreaming vortices and viscosity decrease of the electrolyte solution induced by the acoustofluidic field [40,42]. The vibration the battery and ultrasoniccan fieldbeinclarified the electrolyte can be clarified in the following sonic field in the electrolyte in the following simulation results. simulation results

Measured vibration distribution at 161 kHzatand

Findings

Conclusions