Bioinspired Separator with Ion-Selective Nanochannels for Lithium Metal Batteries

Yi Chen; Philip Mickel; Huijie Pei; Yingfeng Wen; Xin Guan; Yun Wang; Xuyang Wang; Omar Al Mhtachem; Cheng Zhang; Hui Nie; Xingping Zhou; Petr Kral; Xiaolin Xie

doi:10.1021/acsami.3c01311

Bioinspired Separator with Ion-Selective Nanochannels for Lithium Metal Batteries

ACS Appl Mater Interfaces. 2023 Apr 12;15(14):18333-18342. doi: 10.1021/acsami.3c01311. Epub 2023 Mar 28.

Authors

Yi Chen¹, Philip Mickel², Huijie Pei¹, Yingfeng Wen¹, Xin Guan¹, Yun Wang¹, Xuyang Wang¹, Omar Al Mhtachem², Cheng Zhang³, Hui Nie¹, Xingping Zhou¹, Petr Kral⁴, Xiaolin Xie¹

Affiliations

¹ Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
² Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States.
³ Australian Institute for Bioengineering and Nanotechnology and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of Queensland, Brisbane, Queensland 4072, Australia.
⁴ Department of Chemistry and Departments of Physics, Pharmaceutical Sciences, and Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, United States.

PMID: 36976832
DOI: 10.1021/acsami.3c01311

Abstract

The free transport of anions through commercial polyolefin separators used in lithium metal batteries (LMBs) gives rise to concentration polarization and rapid growth of lithium dendrites, leading to poor performance and short circuits. Here, a new poly(ethylene-co-acrylic acid) (EAA) separator with functional active sites (i.e., carboxyl groups) distributing along the pore surface was fabricated, forming bioinspired ion-conducting nanochannels within the separator. As the carboxyl groups effectively desolvated Li⁺ and immobilized anion, the as-prepared EAA separator selectively accelerated the transport of Li⁺ with transference number of Li⁺ (t_Li⁺) up to 0.67, which was further confirmed by molecular dynamics simulations. The battery with the EAA separator can be stably cycled over 500 h at 5 mA cm^-2. The LMBs with the EAA separator have exceptional electrochemical performance of 107 mAh g^-1 at 5 C and a capacity retention of 69% after 200 cycles. This work provides new commercializable separators toward dendrite-free LMBs.

Keywords: ion-selective nanochannels; lithium anode; lithium metal battery; poly(ethylene-co-acrylic acid); separator.