Journal of Bionic Engineering (2022) 19:1014–1023  https://doi.org/10.1007/s42235-022-00173-5

3D-Printed Bio-inspired Multi-channel Cathodes for Zinc–air Battery Applications 

Xin Men1  · Zhiyuan Li1  · Wei Yang2  · Mi Wang2  · Song Liang1  · Hang Sun1  · Zhenning Liu1  · Guolong Lu1 

1 Key Laboratory of Bionic Engineering (Ministry of Education), College of Biological and Agricultural Engineering, Jilin University, Changchun 130022, Jilin, People’s Republic of China 

2 Engineering College, Changchun Normal University, Changchun 130032, People’s Republic of China

Abstract It is of great signifcance to enhance mass transfer and improve active surface area in cathodes for zinc–air batteries (ZABs), which promote oxygen reduction reaction (ORR) efciency and power outputs. Nature has endowed some tissues with special structures to have efcient mass transfer properties and high active surface area. As an important mass transfer part of trees, xylem contains massive long and partially aligned channels, which provides numerous “passageway” and high active surface area for plants to facilitate the efcient transport of oxygen and inorganic salts. The multi-channel structures give an important insight to develop high efcient air cathode. Herein, 3D-printed bio-inspired multi-channel cathodes (BMCs), inspired by xylem structures, have been developed for high-performance ZABs via 3D printing. Channels of bionic cathode contribute to forming a continuous supply of oxygen from air. As a result, massive tri-phase boundary regions, where ORR happens, are formed inside of cathode. Moreover, the 3D-printed metal-based framework can facilitate electron transfer during ORR process. Benefting from the multi-channel framework, the assembled ZABs with BMC-600 show excellent electrochemical performances in terms of the high power density of 170.1 mW cm?2 and a high open-circuit voltage of 1.51 V. Therefore, BMCs provide a potential alternative as promising cathode for metal–air batteries. 

Keywords Zinc–air battery · Bio-inspired · 3D printing · Mass transfer

OCV plots of the ZABs with CC, SSM, XCs and BMCs (A). The OCV histograms of CC, SSM, XCs and BMCs (B). Nyquist plots of the ZABs with CC, SSM and XCs and BMCs (C) from 100 kHz to 0.01 Hz. The resistance histograms of CC, SSM, XCs and BMCs (D)