Rationally Designed PEGDA-LLZTO Composite Electrolyte for Solid-State Lithium Batteries

Xingwen Yu; Yijie Liu; John B Goodenough; Arumugam Manthiram

doi:10.1021/acsami.1c07547

Rationally Designed PEGDA-LLZTO Composite Electrolyte for Solid-State Lithium Batteries

ACS Appl Mater Interfaces. 2021 Jul 7;13(26):30703-30711. doi: 10.1021/acsami.1c07547. Epub 2021 Jun 28.

Authors

Xingwen Yu¹, Yijie Liu¹, John B Goodenough¹, Arumugam Manthiram¹

Affiliation

¹ Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States.

PMID: 34180236
DOI: 10.1021/acsami.1c07547

Abstract

A novel composite electrolyte is rationally designed with a polyethylene glycol diacrylate (PEGDA) polymer and a garnet-type fast lithium-ion conductor (Li_6.4La₃Zr_1.4Ta_0.6O₁₂, LLZTO) for solid-state lithium batteries. The LLZTO ceramic phase is incorporated into the PEGDA polymeric matrix as nanoparticles. The ionic conductivity of the composite is further optimized with a succinonitrile plasticizer. The solid composite membranes are synthesized via a tape casting process followed by a UV curing procedure. The resulting solid-state composite electrolyte delivers a room-temperature Li⁺-ion conductivity of 3.1 × 10^-4 S cm^-1 and can sustain an electrochemical polarization potential up to 4.6-4.7 V (vs Li⁺/Li). The compositing approach harnesses the advantages of both polymeric PEGDA and ceramic LLZTO. In addition to enhancing the ionic conductivity, the LLZTO ceramic filler can suppress Li dendrites. The polymeric phase of PEGDA facilitates good interfacial contact between the solid electrolyte and the electrodes. The solid-state cells fabricated with the composite solid electrolyte, lithium-metal anode, and LiNi_0.8Mn_0.1Co_0.1O₂ (NMC 811) cathode show long cyclability.

Keywords: composite electrolyte; electrochemistry; garnet lithium-ion conductor; polymer matrix; solid-state lithium batteries.