Sodium Super Ionic Conductor-Type Hybrid Electrolytes for High Performance Lithium Metal Batteries

Composite solid electrolytes (CSEs), composed of sodium superionic conductor (NASICON)-type Li<sub>1+x</sub>Al<sub>x</sub>Ti<sub>2&#8210;x</sub>(PO<sub>4</sub>)<sub>3</sub> (LATP), poly (vinylidene fluoride-hexafluoro propylene) (PVDF-H...

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Bibliographic Details
Main Authors: Sung, Po-Yu, Lu, Mi, Hsieh, Chien-Te, Ashraf Gandomi, Yasser, Gu, Siyong, Liu, Wei-Ren
Other Authors: Massachusetts Institute of Technology. Department of Chemical Engineering
Format: Article
Published: Multidisciplinary Digital Publishing Institute 2023
Online Access:https://hdl.handle.net/1721.1/148017
Description
Summary:Composite solid electrolytes (CSEs), composed of sodium superionic conductor (NASICON)-type Li<sub>1+x</sub>Al<sub>x</sub>Ti<sub>2&#8210;x</sub>(PO<sub>4</sub>)<sub>3</sub> (LATP), poly (vinylidene fluoride-hexafluoro propylene) (PVDF-HFP), and lithium bis (trifluoromethanesulfonyl)imide (LiTFSI) salt, are designed and fabricated for lithium-metal batteries. The effects of the key design parameters (i.e., LiTFSI/LATP ratio, CSE thickness, and carbon content) on the specific capacity, coulombic efficiency, and cyclic stability were systematically investigated. The optimal CSE configuration, superior specific capacity (~160 mAh g<sup>&minus;1</sup>), low electrode polarization (~0.12 V), and remarkable cyclic stability (a capacity retention of 86.8%) were achieved during extended cycling (&gt;200 cycles). In addition, with the optimal CSE structure, a high ionic conductivity (~2.83 &times; 10<sup>&minus;4</sup> S cm<sup>&minus;1</sup>) was demonstrated at an ambient temperature. The CSE configuration demonstrated in this work can be employed for designing highly durable CSEs with enhanced ionic conductivity and significantly reduced interfacial electrolyte/electrode resistance.