Ionic liquid incorporated nanocomposite polymer electrolytes for rechargeable lithium ion battery: A way to achieve improved electrochemical and interfacial properties

Salt Effects on the Mechanical Properties of Ionic Conductive Polymer: A Molecular Dynamics Study

Functional polymers can be used as electrolyte and binder materials in solid-state batteries. This often requires performance targets in terms of both the transport and mechanical properties. In this work, a model ionic conductive polymer system, i.e., poly(ethylene oxide)-LiTFSI, was used to study the impact of salt concentrations on mechanical properties, including different types of elastic moduli and the viscoelasticity with both nonequilibrium and equilibrium molecular dynamics simulations. We found an encouragingly good agreement between experiments and simulations regarding Young's modulus, bulk modulus, and viscosity. In addition, we identified an intermediate salt concentration at which the system shows high ionic conductivity, high Young's modulus, and short elastic restoration time. Therefore, this study laid the groundwork for investigating ionic conductive polymer binders with self-healing functionality from molecular dynamics simulations.

Development of biochar/HDPE composites and characterization of the effects of carbon loadings on the electromagnetic shielding properties

The aim of this research is to develop high carbon-yielding biochar from pinewood, coffee husk, sugarcane bagasse, and maize cob and to characterize the biochar/HDPE composites for electromagnetic (EM) shielding application. During the biochar/HDPE composites fabrication, slow pyrolysis and compression molding manufacturing were used. The enhanced properties characterizations were conducted by using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), differential thermal analysis (DTA), Fourier transform spectrometry (FTIR), Brunauer-Emmet-Teller (BET) analysis, digital multi-meter, and proximity analysis. The results of biochar pyrolysis showed the maximum carbon yield of 74.6 %, 68.9 %, 68.4 %, and 40 % for pine wood, maize cob, sugarcane bagasse, and coffee husk respectively. The BET analysis showed the maximum specific surface area (734.5 m2/g), pore volume (0.2364 cm3/g), and pore radius (9.897 Å) from the pine wood biochar. The biochar loading analysis results showed that the 30 % and 40 % pine wood biochar significantly enhanced the electrical conductivity, thermal conductivity, thermal stability, crystallinity, and EM shielding effectiveness (SE) of the biochar/HDPE composites. In particular, the biochar/HDPE composite with 30 wt% pine wood biochar showed the highest thermal conductivity of 2.219 W/mK, and the 40 wt% pine wood biochar/HDPE composite achieved the highest electrical conductivity of 4.67 × 10-7 S/cm and EM SE of 44.03 dB at 2.1 GHz.

Solid polymer electrolytes reinforced with porous polypropylene separators for all-solid-state supercapacitors

Solid polymer electrolytes (SPEs) encounter the challenge of balancing high ionic conductivity and mechanical strength. Ionic liquids, which are among the contenders to be used in high-performance supercapacitors, have difficulty infiltrating commercial polyolefin separators for combined applications. In this study, a novel SPE involving uniform infiltration in the micropores of commercial polyolefin separators with polyethylene oxide (PEO), lithium salt, and different proportions of added ionic liquid was developed. The composite membranes combining ionic liquid-filled SPE with polypropylene (PP) microporous separators simultaneously achieve excellent mechanical strength and high-ionic conductivity. The low wettability of pure ionic liquids and commercial polyolefin-based separators is addressed. The 70 wt% IL-filled solid electrolyte composite membrane (PLI(70)@PP) exhibits a high ionic conductivity (2.9 × 10-3 S cm-1), low resistance at the electrolyte-electrode interface and excellent mechanical strength (128 MPa) at 25 °C. The all-solid-state supercapacitor using PLI(70)@PP exhibits a specific capacitance of 158 F g-1 at 0.1 A g-1 and stable cycle performance. The proposed method can be performed via high-volume roll-to-roll processing to obtain high-performance all-solid-state supercapacitors (ASSCs) for engineering applications.

Review on Synthesis and Properties of Lithium Lanthanum Titanate

The rapid development of portable electronic devices and the efforts to find alternatives to fossil fuels have triggered the rapid development of battery technology. The conventional lithium-ion batteries have reached a high degree of sophistication. However, improvements related to specific capacity, charge rate, safety and sustainability are still required. Solid state batteries try to answer these demands by replacing the organic electrolyte of the standard battery with a solid (crystalline, but also polymer and hybrid) electrolyte. One of the most promising solid electrolytes is Li3xLa2/3-xTiO3 (LLTO). The material nevertheless presents a set of key challenges that must be resolved before it can be used for commercial applications. This review discusses the synthesis methods, the crystallographic and the ionic conduction properties of LLTO and the main limitations encountered through a number of selected studies on this material.

Double-Network Polymer Electrolytes with Ionic Liquids for Lithium Metal Batteries

Solid-state polymer electrolytes have become promising candidates for high-energy-density lithium metal batteries (LMBs). However, they suffer from low ionic conductivities at room temperature. In this work, two types of composite polymer electrolytes based on a double-network polymer, an ionic liquid (IL) of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr14TFSI) or 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl) imide (EmimTFSI), and bis(trifluoromethane)sulfonamide lithium salt (LiTFSI) were prepared by a facile one-pot method. The two types of CPEs possess good mechanical properties, excellent thermal stability, and high ionic conductivities greater than 10−4 S cm−1 at 20 °C with 26 wt% IL. The performance diversity of the CPEs was also carefully investigated through a series of electrochemical measurements. Although the CPEs containing EmimTFSI show higher ionic conductivities than those of CPEs with Pyr14TFSI, the latter ones have wider electrochemical stability windows and better resistance to the growth of lithium dendrites. Moreover, CPE with 34 wt% Pyr14TFSI leads to Li/LiFePO4 batteries with favorable rate capability and cycling stability and a columbic efficiency of 98.8% at 20 °C, which suggests that CPEs are promising for practical application in solid-state LMBs.

Ionic Liquid-Based Electrolytes for Energy Storage Devices: A Brief Review on Their Limits and Applications

Since the ability of ionic liquid (IL) was demonstrated to act as a solvent or an electrolyte, IL-based electrolytes have been widely used as a potential candidate for renewable energy storage devices, like lithium ion batteries (LIBs) and supercapacitors (SCs). In this review, we aimed to present the state-of-the-art of IL-based electrolytes electrochemical, cycling, and physicochemical properties, which are crucial for LIBs and SCs. ILs can also be regarded as designer solvents to replace the more flammable organic carbonates and improve the green credentials and performance of energy storage devices, especially LIBs and SCs. This review affords an outline of the progress of ILs in energy-related applications and provides essential ideas on the emerging challenges and openings that may motivate the scientific communities to move towards IL-based energy devices. Finally, the challenges in design of the new type of ILs structures for energy and environmental applications are also highlighted.

Review on Polymer-Based Composite Electrolytes for Lithium Batteries

Lithium-ion batteries have dominated the high performance and mobile market for last decade. Despite their dominance in many areas, the development of current commercial lithium-ion batteries is experiencing bottlenecks, limited by safety risks such as: leakage, burning, and even explosions due to the low-boiling point organic liquid electrolytes. Solid electrolyte is a promising option to solve or mitigate those issues. Among all solid electrolytes, polymer based solid electrolytes have the advantages of low flammability, good flexibility, excellent thermal stability, and high safety. Numerous researchers have focused on implementing solid polymer based Li-ion batteries with high performance. Nevertheless, low Li-ion conductivity and poor mechanical properties are still the main challenges in its commercial development. In order to tackle the issues and improve the overall performance, composites with external particles are widely investigated to form a polymer-based composite electrolyte. In light of their work, this review discusses the progress of polymer-based composite lithium ion's solid electrolytes. In particular, the structures, ionic conductivities, electrochemical/chemical stabilities, and fabrications of solid polymer electrolytes are introduced in the text and summarized at the end. On the basis of previous work, the perspectives of solid polymer electrolytes are provided especially toward the future of lithium ion batteries.

Recent Advances in Metal Chalcogenides (MX; X = S, Se) Nanostructures for Electrochemical Supercapacitor Applications: A Brief Review

Supercapacitors (SCs) have received a great deal of attention and play an important role for future self-powered devices, mainly owing to their higher power density. Among all types of electrical energy storage devices, electrochemical supercapacitors are considered to be the most promising because of their superior performance characteristics, including short charging time, high power density, safety, easy fabrication procedures, and long operational life. An SC consists of two foremost components, namely electrode materials, and electrolyte. The selection of appropriate electrode materials with rational nanostructured designs has resulted in improved electrochemical properties for high performance and has reduced the cost of SCs. In this review, we mainly spotlight the non-metallic oxide, especially metal chalcogenides (MX; X = S, Se) based nanostructured electrode materials for electrochemical SCs. Different non-metallic oxide materials are highlighted in various categories, such as transition metal sulfides and selenides materials. Finally, the designing strategy and future improvements on metal chalcogenide materials for the application of electrochemical SCs are also discussed.

An enhanced electrochemical and cycling properties of novel boronic Ionic liquid based ternary gel polymer electrolytes for rechargeable Li/LiCoO2 cells

A new generation of boronic ionic liquid namely 1-ethyl-3-methylimidazolium difluoro(oxalate)borate (EMImDFOB) was synthesized by metathesis reaction between 1-ethyl-3-methylimiazolium bromide and lithium difluoro(oxalate)borate (LiDFOB). Ternary gel polymer electrolyte membranes were prepared using electrolyte mixture EMImDFOB/LiDFOB with poly vinylidenefluoride-co-hexafluoropropylene (PVdF-co-HFP) as a host matrix by facile solvent-casting method and plausibly demonstrated its feasibility to use in lithium ion batteries. Amongst ternary gel electrolyte membrane, DFOB-GPE3, which contained 80 wt% of EMImDFOB/LiDFOB and 20 wt% PVdF-co-HFP, showed excellent electrochemical and cycling behaviors. The highest ionic conductivity was found to be 10⁻³ Scm⁻¹ at 378 K. Charge-discharge profile of Li/DFOB-GPE3/LiCoO₂ coin cell displayed a maximum discharge capacity of 148.4 mAhg⁻¹ at C/10 rate with impressive capacity retention capability and columbic efficiency at 298 K.

Headway in rhodanide anion based ternary gel polymer electrolytes (TILGPEs) for applications in rechargeable lithium ion batteries: an efficient route to achieve high electrochemical and cycling performances

For the first time, a new category of rhodanide anion based ternary ionic liquid gel polymer electrolytes has been synthesized and characterized for its applications in lithium ion batteries.