High-Performance Room Temperature Lithium-Ion Battery Solid Polymer Electrolytes Based on Poly(vinylidene fluoride-co-hexafluoropropylene) Combining Ionic Liquid and Zeolite

Abstract

The demand for more efficient energy storage devices has led to the exponential growth of lithium-ion batteries. To overcome the limitations of these systems in terms of safety and to reduce environmental impact, solid-state technology emerges as a suitable approach. This work reports on a three-component solid polymer electrolyte system based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), the ionic liquid 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]), and clinoptilolite zeolite (CPT). The influences of the preparation method and of the dopants on the electrolyte stability, ionic conductivity, and battery performance were studied. The developed electrolytes show an improved room temperature ionic conductivity (1.9 × 10 −4 S cm −1 ), thermal stability (up to 300 °C), and mechanical stability. The corresponding batteries exhibit an outstanding room temperature performance of 160.3 mAh g −1 at a C/ 15-rate, with a capacity retention of 76% after 50 cycles. These results represent a step forward in a promising technology aiming the widespread implementation of solid-state batteries.

Three‐Component Solid Polymer Electrolytes Based on Li‐Ion Exchanged Microporous Silicates and an Ionic Liquid for Solid‐State Batteries

“…[40] These voids have been shown to positively contribute to battery performance, as stated in previous works. [31] The homogeneous nature of the composites along the cross-section proves the good compatibility between the three components (polymer, ionic liquid, and zeolites), and the absence of spherulites is attributed to the hindered crystallization due to the high loading content. [41] Figure 2a,b shows the XRD patterns of PVDF-HFP and the corresponding composites doped with the microporous silicates CPT, ETS-10, and ETS-4, without and with ion exchange, respectively.…”

“…The IL [BMIM][SCN] was selected on account of its high room temperature ion conductivity, which makes it suitable for SPE applications, as proved in previous works [13b,31] …”

“…[31] Thus, it was proved that combining zeolites and ILs is a good strategy to achieve effective SPEs by combining the high ionic conductivity of the IL and the stabilization of battery performance by the zeolite. [31] Further, the ion exchange capacity of some zeolites is also an interesting feature of these structures to take advantage of, as it allows a better tuning of their characteristics in specific ways. [32] Thus, to develop high-performance SPEs, this work focus on different zeolite structures, natural zeolite clinoptilolite (CPT), and synthetic microporous titanosilicates ETS-4 and ETS-10 with and without ion exchange, combined with the IL [BMIM][SCN] entrapped within a polar PVDF-HFP polymer matrix.…”

Ionic Conductivity, Na Plating–Stripping, and Battery Performance of Solid Polymer Na Ion Electrolyte Based on Poly(vinylidene fluoride) and Poly(vinyl pyrrolidone)

“…However, the SiO 2 and PVP-containing SPE-5 showed lower ionic conductivity than the binder-less SPE-4. Among the literature reported PVDF-based SPEs, the ionic conductivity of SPE-2 at room temperature was one of the highest reported values, as shown in Table . ,, …”

“…Among the literature reported PVDF-based SPEs, the ionic conductivity of SPE-2 at room temperature was one of the highest reported values, as shown in Table 2. 18,48,49 The low conductivity may be explained by the competing interaction of PVP and SiO 2 toward Na-salt, leading to less ion dissociation in the SPE-5 system. A filler and binder-less sample (SPE-6; PVDF/NaPF 6 = 9:1) was prepared to investigate the effect of PVP binder on ionic conductivity.…”