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A new type of nanopolypyrrole/organically modified montmorillonite-ionic liquid gel polymer electrolyte (ppy/OMMT-ILGPE) is prepared based on nanopolypyrrole/organically modified montmorillonite (ppy/OMMT), N-butyl-N- methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PP14TFSI), lithium-bis(trifluoromethanesulfonyl) (LiTFSI), polyvinylidene difluoride (PVDF), methyl methacrylate (MMA), and benzoyl peroxide (BPO) by an in situ method. The effect of nano-ppy/OMMT on the physical and electrochemical properties of an ionic liquid gel polymer electrolyte is demonstrated. The results show that nano-ppy/OMMT-ILGPE has a porous structure with a large surface area, and the diameter of the pores on the surface is approximately 1-2 μm. The Li+ transference number of 0.72 is achieved, and the ionic conductivity reaches up to 1.2 × 10−3 S/cm at room temperature. Nano-ppy/OMMT-ILGPE has good thermal stability and mechanical properties. Meanwhile, nano-ppy/OMMT-ILGPE has fine cycle performance in the Li|nano-ppy/OMMT-ILGPE|LiNi1/3Co1/3Mn1/3O2 coin cell. The good electrochemistry performance of nano-ppy/OMMT-ILGPE means that it can act as an ideal gel polymer electrolyte material for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Nanopolypyrrole/organic montmorillonite- (nano-ppy/OMMT-) coated separator is prepared by coating nano-ppy/OMMT on the surface of polyethylene (PE). Nano-ppy/OMMT-coated separator with three-dimensional and multilayered network structure is beneficial to absorb more organic electrolyte, enhancing the ionic conductivity (reach 4.31 mS·cm-1). Meanwhile, the composite separator exhibits excellent thermal stability and mechanical properties. The strong covalent bonds (Si-F) are formed by the nucleophilic substitution reaction between F− from the thermal decomposition and hydrolysis of LiPF6 and the covalent bonds (Si-O) of nano-ppy/OMMT. The Si-F can effectively prevent the formation of HF, POF3, and LiF, resulting in the inhibition of the disproportionation of Mn3+ in LiNi1/3Co1/3Mn1/3O2 material as well as reducing the internal resistance of the cell. Therefore, the nano-ppy/OMMT-coated separator exhibits outstanding capacity retention and cycling performance at 80°C. [ABSTRACT FROM AUTHOR]

A microbistable piezoelectric energy harvester has been developed. The harvester was based on a center-fixed and quadrilateral-free microbistable plate with mass blocks placed at the four corners. Considering the thermoelectromechanical coupling effect, a nonlinear oscillation differential equation was established by Hamilton's principle. Strain gradient theory was applied to consider the size effect, and von Karman theory was used to consider the large deformation effect. The influences of the laying position and area of the piezoelectric layer on the efficiency of energy capture were investigated. The voltage-frequency response of the nonlinear system was investigated, and the snap-through behavior of the bistable plate results in energy harvesting achieving the ideal broaden frequency range before the resonance region. [ABSTRACT FROM AUTHOR]