Influence of a rigid polystyrene block on the free volume and ionic conductivity of a gel polymer electrolyte based on poly(methyl methacrylate)‐block‐polystyrene

Abstract

Diblock copolymers poly(methyl methacrylate)-block-polystyrene with three different molar ratios [poly(methyl methacrylate)/polystyrene (PS) 5 1:1, 1:1.5, and 1:1.8] were synthesized by atom transfer radical polymerization and used as a polymer matrix for gel polymer electrolytes (GPEs). The positron annihilation lifetime spectroscopy was applied to determine the free-volume behaviors of different GPEs, respectively. We illustrated that a proper PS ratio may led to the formation of a high fraction of free volume, and the influence of the PS ratio on the free-volume fraction was caused by the different morphologies of the GPEs because of the different packing densities of the PS rigid block. The ionic conductivity was correlated with the free volume in the GPE through the study of the ionic conductivity dependence on the temperature; this followed the Vogel-Tamman-Fulcher equation. Moreover, an ionic conductive model was proposed, in which variations of the free-volume behavior provide different ionic-conducting abilities. Thermogravimetric analysis indicated that GPEs based on different block copolymers exhibited high liquid-electrolyte preservation properties.

Recent advances in gel polymer electrolyte for high-performance lithium batteries

“…Blending, copolymerization and introduction of nanofillers have been attempted to improve mechanical stability of GPE based on PMMA. Guan et al [14] synthesized the di-block copolymers PMMA-block-polystyrene (PS) with three different molar ratios (PMMA/PS) by atom transfer radical polymerization to use as a polymer matrix for GPE, and the synthesis of copolymers was displayed in Fig. 2 (b).…”

Synthesis and characterization of multi‐ionic block copolymers and blended membranes for chemical protective clothing applications

“…36 It is known that PS has a higher free volume than methacrylates and that its proper addition to a polymer matrix can benefit the ionic transport through a membrane. 37 The behavior observed in Figure 11a also could be explained due to the contribution of the methacrylate blocks to maintaining a low free volume structure. When the copolymers were sulfonated, a hydrophilic affinity was added to the matrix; however, it was held at a low level (25%-35%), contributing to the water/DMMP selectivity.…”

Polymer‐Based Solid‐State Electrolytes for High‐Energy‐Density Lithium‐Ion Batteries – Review

“…Ma et al synthesized PMMA/polystyrene copolymers with different molar ratios and introduced PC-LiClO 4 as the plasticizer to prepare GPE. [111] The introduction of polystyrene block improved the mechanical properties, thermal stability, and liquid preservation ability of the GPE. Utilizing the lithium-stable property of PMMA, Sui et al synthesized a unique PAN (core)-PMMA (shell) nanofiber structure by coaxial electrospinning, effectively avoiding the direct PAN/lithium metal anode contact.…”

“…synthesized PMMA/polystyrene copolymers with different molar ratios and introduced PC‐LiClO 4 as the plasticizer to prepare GPE. [ 111 ] The introduction of polystyrene block improved the mechanical properties, thermal stability, and liquid preservation ability of the GPE. Utilizing the lithium‐stable property of PMMA, Sui et al.…”