Poly[poly(ethylene glycol) methacrylate]-modified starch-based solid and gel polymer electrolytes for high performance Li-ion batteries.

The idea of replacing liquid electrolytes with polymer electrolytes has been successful and the development of these electrolytes has provided acceptable results. With the start of using natural polymers in the polymer industry, as well as starch, these materials can be one of the most important candidates for the polymer matrix in electrolytes. In this study, starch has been investigated as a polymer electrolyte, poly[poly(ethylene glycol) methacrylate] (PEGMA) is grafted to the starch by radical polymerization, and synthesized copolymers are used as solid polymer electrolytes (SPEs). Furthermore, by adding N,N'-methylenebisacrylamide (MBA) as a cross-linking agent, gel polymer electrolytes (GPEs) are produced after swelling in the liquid electrolyte. After characterization, the synthesized polymer electrolytes are investigated in terms of electrochemical properties. The best ionic conductivity of 3.8 × 10-5 S cm-1 is obtained for SPEs whereas it is obtained 4.3 × 10-3 S cm-1 for GPEs at room temperature. The ion transfer number in the range of 0.47-0.91 confirms the compatibility between the electrolytes and electrode. Also, the prepared polymer electrolytes present excellent electrochemical properties, including, a wide electrochemical stability window above 4.7 V, good specific capacities in the range of 170-200 mAh g-1 with a storage capacity of more than 92 %, and Coulombic efficiency of about 98 % after 100 cycles at 0.2 C.

Synthesis and evaluation of cellulose/polypyrrole composites as polymer electrolytes for lithium-ion battery application.

Natural polymers as battery components have a number of advantages, including availability, biodegradability, unleakage, stable form, superior process, electrochemical stability, and low cost. In other sides, conductive polymers can improve the electrochemical properties of the battery, such as charge/discharge rates, cycling stability, and overall energy storage capacity. Therefore, the combination of these two materials can provide acceptable features. In this study, polymer electrolytes based on cellulose have been synthesized by solution casting method to prepare a thin polymer film. Then, polypyrrole (PPy) was blended with cellulose in different weight ratios. To prevent electrical conductivity of blends, PPy was used <10 wt%. The electrochemical properties of prepared electrolytes have been investigated by different methods. The results showed that ionic conductivity was increased by addition of PPy to cellulose due to the creation of pores and also due to the high dielectric constant of conductive polymers. All synthesized electrolytes had suitable ionic conductivity (in the range of 10-3 S cm-1), significant charge capacity, stable cyclic performance, excellent electrochemical stability (above 4.8 V), and high cation transfer number (between 0.38 and 0.66 for pure cellulose and the sample containing 10 wt% PPy).

Adsorption kinetics of methyl orange from water by pH-sensitive poly(2-(dimethylamino)ethyl methacrylate)/nanocrystalline cellulose hydrogels.

A series of hydrogel nanocomposites was fabricated by in situ polymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) in presence of different amounts of (amine- and alkyl-modified) nanocrystalline cellulose (NCC). Modification and nanocomposites properties were proved by different analysis methods such as Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), and field emission scanning electron microscopy (FE-SEM). The new hydrogel nanocomposites were applied for removing methyl orange (MO) used as anionic dye and presented in process water at different pH values. The effects of the fabrication process such as modification and content of NCC, contact time, and pH value on swelling ratio (SR), and equilibrium adsorption kinetics were studied. Results showed that the swelling ratio of PDMAEMA-based nanocomposites varied with the different types of nanoparticles showing the significant effect of the modification process. The MO adsorption into the hydrogel nanocomposites was affected by intermolecular and electrostatic interactions between functional groups of hydrogel and dye. The adsorption capacity decreased at high pH value, and it was significantly affected type of nanoparticles introduced into the hydrogel network. The addition of unmodified NCC did not affect adsorption kinetics significantly. Finally, adsorption kinetics was investigated by pseudo-first-order, pseudo-second-order and intraparticle diffusion models where pseudo-first-order model showed the best correlation with experimental results.