Electrospun Li(TFSI)@Polyethylene Oxide Membranes as Solid Electrolytes

Abstract

Thin membranes of lithium‐bis(trifluoromethan)sulfonimide@poly (ethylene oxide) (or Li(TFSI)@PEO) were fabricated by electrospinning from acetonitrile solutions of the starting materials at room temperature. Membranes were tested with and without succinonitrile (SN), acting as a plasticizer to enhance the ion mobility in the systems. Our experiments substantiate, that SN does influence the electrochemical performance and physical properties of the membranes. Homogeneous amorphous membranes were only realized for SN‐containing samples, while phase segregation and crystallization occurred for SN‐free representatives. Membranes of different compositions were tested and the optimum molar mixture of PEO:SN:Li(TFSI), in terms of membrane conductivity, was identified as 36:8:1. Conductivities up to up to 2.8 × 10–4 S·cm–1 were determined by impedance spectroscopy for this membrane. Used as solid electrolytes without the aid of any additional electrolyte in symmetric Li vs. Li cells, a reasonable stability upon Li cycling could be observed. Here we illustrate that electrospun plasticizer‐modified Li(TFSI)@PEO membranes show high conductivities at very low conductive salt concentrations, compared with solution casted or hot pressed representatives. This feature renders these materials as potential candidates for separators in all solid‐state batteries or related energy storage applications.

Nanofibrous poly(ethylene oxide)‐based structures incorporated with multi‐walled carbon nanotube and graphene oxide as all‐solid‐state electrolytes for lithium ion batteries

“…reported an electrospinning procedure as an efficient and facile method for the fabrication of all‐solid‐state nanofibrous electrolytes applicable in LIBs. In 2018, Walke et al . also demonstrated the highest ionic conductivity of 0.28 mS cm −1 for an electrospun PEO/LiTFSI electrolyte.…”

All-Solid-State Electrospun Poly(vinylidene fluoride-co-hexafluoropropylene)/Li7.1La3Ba0.05Zr1.95O12 Nanohybrid Membrane Electrolyte for High-Energy Li-Ion Capacitors

“…Presence of a more amorphous region is confirmed due to the appearance of the smooth surface of nanofibers, which fulfill the aim of a flexible and rigid polymer electrolyte, solely responsible for the conduction of ions independently in the polymer electrolyte. 44,45 The outer surface of the membrane is accumulated by the LLBZO nanoparticle as well as an electrolyte in which these membranes are soaked for 24 h. The soaked membranes were dried for 6 h to get the all-solidstate esHPME. Figure S1 shows the SEM images of 5 and 15 wt % LLBZO-incorporated PVDF-HFP.…”

Electrospun core‐shell nanofibers based on polyethylene oxide reinforced by multiwalled carbon nanotube and silicon dioxide nanofillers: A novel and effective solvent‐free electrolyte for lithium ion batteries

“…Moreover, the existence of the small pores in the electrospun structures facilitates the mobility and migration of the Li + ions. Hence, the electrospun membranes provide higher ionic conductivities compared with the solution‐casted ones 24‐26 . Previous studies clearly showed the effect of inert oxide fillers (including SiO 2 , Al 2 O 3 , TiO 2, and ZnO) on the ionic conductivity enhancement of the electrospun PEO‐based membranes 27,28 .…”

“…Hence, the electrospun membranes provide higher ionic conductivities compared with the solution-casted ones. [24][25][26] Previous studies clearly showed the effect of inert oxide fillers (including SiO 2 , Al 2 O 3 , TiO 2, and ZnO) on the ionic conductivity enhancement of the electrospun PEO-based membranes. 27,28 According to the obtained results, the highest ionic conductivity of 0.087 mS.cm −1 could be obtained by insertion of SiO 2 nanofillers into the PEO-based electrospun fibers.…”