A Composite Gel Polymer Electrolyte with High Performance Based on Poly(Vinylidene Fluoride) and Polyborate for Lithium Ion Batteries

Abstract

A composite membrane based on electrospun poly(vinylidene fl uoride) (PVDF) and lithium polyvinyl alcohol oxalate borate (LiPVAOB) exhibiting high safety (self-extinguishing) and good mechanical property is prepared. The ionic conductivity of the as-prepared gel polymer electrolyte from this composite membrane saturated with 1 mol L −1 LiPF 6 electrolyte at ambient temperature can be up to 0.26 mS cm −1 , higher than that of the corresponding well-used commercial separator (Celgard 2730), 0.21 mS cm −1 . Moreover, the lithium ion transference in the gel polymer electrolyte at room temperature is 0.58, twice as that in the commercial separator (0.27). Furthermore, the absorbed electrolyte solvent is diffi cult to evaporate at elevated temperature. Its electrochemical performance is evaluated by using LiFePO 4 cathode. The obtained results suggest that this gel-type composite membrane shows great possibilities for use in large-capacity lithium ion batteries that require high safety.

Improved Dielectric Properties and Energy Storage Density of Poly(vinylidene fluoride-co-hexafluoropropylene) Nanocomposite with Hydantoin Epoxy Resin Coated BaTiO3

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 12 group (-C-F) of P(VDF-HFP), hydantoin/BT bonds tightly with the polymer host. 46 Thus the BT nanoparticles maintained a homogeneous dispersion in the composites and neglected evidence of defects was observed between both particle-particle and particle-matrix, indicating strong interfacial bonding and excellent compatibility between nanoparticles and the P(VDF-HFP) matrix. The results can be further proved by the high-magnification SEM images of the nanocomposites (see Figure S4 from the Supporting Information).…”

Electrolytes for electrochemical energy storage

“…288 Then, a Na-ion capacitor assembled with this GPEs provided high specific energy of 168 Wh kg ─1 and stable cycling with 85 % of the specific capacitance maintained after 1200 cycles. 234 Also, a Na-ion battery Sb/Na3V2(PO4)3 with a low-cost GPE based on cross-linked PMMA was demonstrated. The cell exhibited a highly reversible electrochemical reaction and a stable cycle performance, which was attributed to the enhanced interfacial properties of the gel-polymer electrolyte, especially at the evaluated temperature.…”

“…Replacing the organic electrolytes with gel polymer electrolytes (GPEs) delivers a promising solution to improve safety by avoiding these crucial issues. [233][234][235] There are extensively explored GPEs based on polymer matrices that are capable of immobilizing a large amount of liquid electrolyte. These GPEs offer both the flexibility of the polymer and the high ionic conductivity of the liquid electrolyte, and enable wide electrochemical windows, excellent cycling durability and improved thermal stability.…”

Fabrication of a novel sandwich-like composite separator with enhanced physical and electrochemical performances for lithium-ion battery

“…For example, various kinds of composite separators were fabricated by mixing functional ingredients with the supporting matrices, such as inorganic nanoparticles (SiO 2 , TiO 2 , Al 2 O 3 , and Sm 2 O 3 , etc.) [26e30], and polyborate [31,32]. It has also been found that the introduction of some functional groups onto the surfaces of polyolefins or non-woven fabrics before coating modification could enhance the compatibility between substrates and support materials and finally to improve the electrolyte uptake [30,33,34].…”