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Abstract Poly(vinylidene fluoride- co -hexafluoropropylene) (P(VDF-HFP))-based composite polymer electrolytes (CPEs) doped with different amounts of CaTiO 3 inorganic fillers are prepared by phase inversion. With adding the CaTiO 3 fillers into the P(VDF-HFP) polymer matrix, the CPE membranes show more abundant and uniform micro-pore structure with lower crystallinity, better thermal stability and mechanical strength. The characterization results show that the ionic conductivity at room temperature and electrochemical working window of the CPE doped with 5 wt% CaTiO 3 fillers (CPE-5) can be up to about 3.557 mS cm−1 and 5.1 V, respectively. The interfacial resistance of the Li/CPE-5/Li simulated cell can quickly stabilize at 750 Ω after 5 days storage, and the assembled LiCoO 2 /CPE-5/Li coin cell shows excellent rate and cycle performance. Moreover, the CPE-5 membrane can still well maintain the original micro-pore structure after 100 cycles at 1.0 C without visible cracks. Those results suggest that the as-fabricated CPE doped with 5 wt% CaTiO 3 inorganic fillers may become a promising polymer electrolyte for the lithium ion battery Graphical abstract Cycling performance and coulombic efficiency plots of the LiCoO 2 /CPE-5/Li battery after 100 cycles at 1.0 C (The insert are the SEM images and digital photographs of the CPE-5 before and after cycle). Unlabelled Image Highlights • P(VDF-HFP)-based CPE membranes doped with different amounts of CaTiO 3 ceramics are fabricated by phase inversion. • The electrolyte uptake and ionic conductivity of the CPE-5 can be up to 187.4% and 3.557 mS cm−1. • The Li/CPE-5/Li simulated cell possesses good interfacial stability. • The assembled LiCoO 2 /CPE-5/Li battery shows good rate and cycle performance. [ABSTRACT FROM AUTHOR]

Abstract: To improve the electrochemical performance of pure poly[(vinylidene fluoride)‐co‐hexafluoropropylene] (P(VDF‐HFP))‐based gel polymer electrolytes, different amounts of monodispersed ZrO2 nanoparticles were introduced to fabricate P(VDF‐HFP)/ZrO2 composite polymer electrolytes (CPEs) using the phase inversion method and activated processes, in which the monodispersed ZrO2 nanoparticles were synthesized by an easy route without any chelating agents or surfactants, and confirmed using scanning electron microscopy, particle size distribution measurement and X‐ray diffraction. The characterization results show that the as‐fabricated CPE membranes present not only an abundant porous structure, but also an improved mechanical strength. In particular, sample CPE‐5 presents the best properties when the doped content of the monodispersed ZrO2 nanoparticles reaches 5 wt% in the polymer matrix, in which the liquid uptake and ionic conductivity at room temperature are about 192.4% and 3.926 mS cm−1, and the electrochemical working window and thermal decomposition temperature can increase to 5.1 V and 420 °C, respectively. Moreover, an assembled LiCoO2/CPE‐5/Li coin cell can deliver excellent rate and cycling performance, in which the discharge specific capacity of the cell can show about 83.95% capacity retention at 2.0 C after 85 cycles. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

To improve the ionic conductivity as well as enhance the mechanical strength of the gel polymer electrolyte, poly(vinylidene fluoride-hexafluoroprolene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with the organic-inorganic hybrid particles poly(methyl methacrylate) -ZrO 2 (PMMA-ZrO 2 ) are prepared by phase inversion method, in which PMMA is successfully grafted onto the surface of the homemade nano-ZrO 2 particles via in situ polymerization confirmed by FT-IR. XRD and DSC patterns show adding PMMA-ZrO 2 particles into P(VDF-HFP) can significantly decrease the crystallinity of the CPE membrane. The CPE membrane doped with 5  wt % PMMA-ZrO 2 particles can not only present a homogeneous surface with abundant interconnected micro-pores, but maintain its initial shape after thermal exposure at 160 °C for 1 h, in which the ionic conductivity and lithium ion transference number at room temperature can reach to 3.59 × 10 −3  S cm −1 and 0.41, respectively. The fitting results of the EIS plots indicate the doped PMMA-ZrO 2 particles can significantly lower the interface resistance and promote lithium ions diffusion rate. The Li/CPE-sPZ/LiCoO 2 and Li/CPE-sPZ/Graphite coin cells can deliver excellent rate and cycling performance. Those results suggest the P(VDF-HFP)-based CPE doped with 5  wt % PMMA-ZrO 2 particles can become an exciting potential candidate as polymer electrolyte for the lithium ion battery. [ABSTRACT FROM AUTHOR]

The organic-inorganic hybrid material poly(styrene-methyl methacrylate)-silica (P(St- MMA)-SiO2) was successfully prepared by in situ polymerization confirmed by Fourier transform infrared spectroscopy and was employed to fabricate poly(vinylidene fluoride-hexafluoropropylene) (P( VDF-HFP)) based composite polymer electrolyte ( CPE) membrane. Desirable CPEs can be obtained by immersing the CPE membranes into 1.0 mol L−1 LiPF6-EC/ DMC/ EMC (LiPF6 ethylene carbonate + dimethyl carbonate + ethylmethyl carbonate) liquid electrolyte for about 0.5 h for activation. The corresponding physicochemical properties were characterized by SEM, XRD, electrochemical impedance spectroscopy and charge-discharge cycle testing measurements. The results indicate that the as-prepared CPEs have excellent properties when the mass ratio of the hybrid P(St- MMA)- SiO2 particles to polymer matrix P( VDF-HFP) reaches 1:10, at which point the SEM analyses show that the as-prepared P(St- MMA)- SiO2 particles are uniformly dispersed in the membrane and the CPE membrane presents a homogeneous surface with abundant interconnected micropores. The XRD results show that there may exist interaction forces between the P(St- MMA)- SiO2 particles and the polymer matrix, which can obviously decrease the crystallinity of the composite membrane. Moreover, the ionic conductivity at room temperature and the electrochemical working window of the CPE membrane can reach 3.146 mS cm−1 and 4.7 V, respectively. The assembled LiCoO2/ CPE/Li coin cell with the CPE presents excellent charge-discharge and C-rate performance, which indicates that P(St- MMA)- SiO2 hybrid material is a promising additive for the P( VDF-HFP) based CPE of the lithium ion battery. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The mesoporous Si/Ti molecular sieve was successfully synthesized from tetrabutyl titanate, tetraethoxysilane and EO 20 PO 70 EO 20 by sol-gel combined with following pyrolysis processes and confirmed by XRD and TEM. The poly (vinylidene fluoride- co -hexafluoropropylene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with Si/Ti molecular sieve were fabricated by phase inversion method and the desirable CPEs were obtained after being activated in liquid electrolytes, which are investigated by SEM, XRD, TG, LSV and EIS measurements. The results show that the CPE doped with 10% Si/Ti molecular sieve ( vs P(VDF-HFP) in weight) presents the most uniform surface with abundant interconnected micro-pores and possesses excellent mechanical tensile strength with high decomposition temperature about 400 °C and wide electrochemical working window about 4.7 V; adding Si/Ti molecular sieve into the system can significantly decrease the crystallinity and improve the ionic conductivity of the as-prepared CPEs, in which the ionic conductivity and lithium ion transference number at room temperature are up to 3.263 mS cm −1 and 0.4292, respectively, and the reciprocal temperature dependence of ionic conductivity follows Vogel-Tamman-Fulcher relation. Furthermore, the anti-shrinkage rate of the as-prepared CPE membrane distinctly outperforms the commercial polyolefin membrane at 120 °C about 2 h. The interfacial resistance of the assembled Li/CPE/Li simulated cell can rapidly increase to a steady value about 548 Ω from the initial value about 362 Ω at 30 °C during 5 days storage, and the assembled Li/CPE/LiCoO 2 coin cell with the electrolyte also show excellent rate and cycle performance, which indicates that this kind of CPE is an exciting potential candidate as polymer electrolyte for the lithium ion battery. [ABSTRACT FROM AUTHOR]

NASICON-type fast ion conductor powders Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) are prepared by spray-drying and sintering processes confirmed by XRD and SEM analyses. Novel poly(vinylidene fluoride-hexafluoropylene) (P(VDF-HFP))-based composite polymer electrolytes (CPEs) doped with various amounts of LATP particles are fabricated via classical inverse-phase method. As a result, the as-prepared CPE-5 membrane can present excellent physicochemical properties when the doped amount is maintained at 5% vs. polymer matrix, in which the interfacial impedance value can rapidly stabilize at 472 Ω and the thermal decomposition temperature can be up to 430 °C, respectively. In particularly, the ionic conductivity can be as high as 3.943 mS cm−1 at 25 °C. In addition, the assembled LiCoO 2 /CPE-5/Li coin cell can deliver a discharge specific capacity of 145.4 mAh g−1 at 1.0 C with 96.93% capacity retention ratio after 25 cycles. These outstanding properties can promote the CPE-5 to be a candidate electrolyte to improve the performance of lithium ion batteries. Brief preparation process and characterization of composite polymer electrolytes doped with various amounts of LATP powders. Unlabelled Image • NASICON-type LATP powders are prepared by spray-drying and sintering methods. • The optimum LATP doping amount is 5% vs. polymer matrix. • The ionic conductivity at room temperature is as high as 3.943 mS cm−1. • The assembled cell delivers a discharge specific capacity of 132.8 mAh g−1 at 1.0 C. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO)/Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) composite solid electrolyte is considered as a promising electrolyte for lithium batteries. However, LLZTO nanoparticles tend to agglomerate in PEO/LLZTO composite polymer electrolyte due to interfacial incompatibility between PEO and LLZTO nanoparticles, which leads to low ionic conductivity, poor interface stability with the electrode, and inferior batteries cycling stability. In order to enhance interfacial compatibility, herein, LLZTO nanoparticles are modified through firstly surface-functionalizing by dopamine coating and then grafting poly (ethylene glycol) (PEG) brush on it via amino and epoxy reaction. As a consequence, the ionic conductivity of LLZTO/PEO composite polymer electrolyte filled with 2 wt% modified LLZTO increases up to 1.1 × 10 − 4 S cm−1, which is about twice and 20 times in comparison with LLZTO/PEO filled with 2 wt% unmodified LLZTO and PEO electrolytes, respectively. Moreover, high oxidation potential of around 4.8 V and ionic transference number of 0.34 as well as good interface stability with lithium anode are also achieved. Thus, LiFePO 4 ||Li all-solid-state lithium metal batteries based on LLZTO/PEO composite polymer electrolyte filled with 2 wt% modified LLZTO exhibit excellent cyclic stability of 152.3 mAh g−1 with capacity retention of 90.35% at 0.5 C after 500 cycles under 60 °C. [Display omitted] • LLZTO were coated with PDA and further grafted with PEGDE to form PEG brush. • PEG-g-LLZTO@PDA nanoparticles can be uniformly dispersed in PEO. • 2 wt% PEG-g-LLZTO@PDA/PEO shows a RT ionic conductivity of 1.1 × 10 − 4 S cm−1. • Li.|2 wt% PEG-g-LLZTO@PDA/PEO|LiFePO 4 battery shows excellent cycling stability. [ABSTRACT FROM AUTHOR]