Nanocomposite solid polymer electrolytes based on semi-interpenetrating hybrid polymer networks for high performance lithium metal batteries

Characterization of Poly(methyl methacrylate)- and Polystyrene-Based Block Copolymers by Liquid Chromatography under Limiting Conditions of Desorption Gradient

Size exclusion chromatography-gradient (SEC-Gradient) is a powerful technique to separate polymers by their chemical composition. The stationary phase is first conditioned with a gradient from adsorli to desorli, and polymer samples are injected after the gradient in SEC conditions. Since its first description in 2011 by Schollenberger and Radke, it has never been applied to block copolymers. Liquid chromatography under limiting conditions of desorption (LC LCD), developed in the 2000s by Berek, allows the separation of block copolymers from their parent homopolymers by injecting some barriers of appropriately chosen solvents at specific injection delays before sample injection. In this work, we propose a new technique close to the LC LCD elution mechanism but applying column conditioning with a global gradient before sample injection, as in SEC-Gradient experiments, namely, liquid chromatography under limiting conditions of desorption gradient (LC LCDG). Using this LC LCDG technique, we managed to baseline separate poly(methyl methacrylate) (PMMA)- and polystyrene (PS)-based block copolymers from their PMMA and PS parent homopolymers. The chromatographic method development to achieve an optimal separation and identify a low molar mass limit is particularly described.

Glass Fiber Reinforced Epoxy-Amine Thermosets and Solvate IL: Towards New Composite Polymer Electrolytes for Lithium Battery Applications

To effectively use (Li) lithium metal anodes, it is becoming increasingly necessary to create membranes with high lithium conductivity, electrochemical and thermal stabilities, as well as adequate mechanical properties. Composite gel polymer electrolytes (CGPE) have emerged as a promising strategy, offering improved ionic conductivity and structural performance compared to polymer electrolytes. In this study, a simple and scalable approach was developed to fabricate a crosslinked polyethylene oxide (PEO)-based membrane, comprising two different glass fiber reinforcements, in terms of morphology and thickness. The incorporation of a solvated ionic liquid into the developed membrane enhances the ionic conductivity and reduces flammability in the resulting CGPE. Galvanostatic cycling experiments demonstrate favorable performance of the composite membrane in symmetric Li cells. Furthermore, the CGPE demonstrated electrochemical stability, enabling the cell to cycle continuously for more than 700 h at a temperature of 40 °C without short circuits. When applied in a half-cell configuration with lithium iron phosphate (LFP) cathodes, the composite membrane enabled cycling at different current densities, achieving a discharge capacity of 144 mAh·g^-1. Overall, the findings obtained in this work highlight the potential of crosslinked PEO-based composite membranes for high-performance Li metal anodes, with enhanced near room temperature conductivity, electrochemical stability, and cycling capability.

Epoxy-Based Interlocking Membranes for All Solid-State Lithium Ion Batteries: The Effects of Amine Curing Agents on Electrochemical Properties

In this study, a series of crosslinked membranes were prepared as solid polymer electrolytes (SPEs) for all-solid-state lithium ion batteries (ASSLIBs). An epoxy-containing copolymer (glycidyl methacrylate-co-poly(ethylene glycol) methyl ether methacrylate, PGA) and two amine curing agents, linear Jeffamine ED2003 and hyperbranched polyethyleneimine (PEI), were utilized to prepare SPEs with various crosslinking degrees. The PGA/polyethylene oxide (PEO) blends were cured by ED2003 and PEI to obtain slightly and heavily crosslinked structures, respectively. For further optimizing the interfacial and the electrochemical properties, an interlocking bilayer membrane based on overlapping and subsequent curing of PGA/PEO/ED2003 and PEO/PEI layers was developed. The presence of this amino/epoxy network can inhibit PEO crystallinity and maintain the dimensional stability of membranes. For the slightly crosslinked PGA/PEO/ED2003 membrane, an ionic conductivity of 5.61 × 10⁻⁴ S cm⁻¹ and a lithium ion transference number (tLi⁺) of 0.43 were obtained, along with a specific capacity of 156 mAh g⁻¹ (0.05 C) acquired from an assembled half-cell battery. However, the capacity retention retained only 54% after 100 cycles (0.2 C, 80 °C), possibly because the PEO-based electrolyte was inclined to recrystallize after long term thermal treatment. On the other hand, the highly crosslinked PGA/PEO/PEI membrane exhibited a similar ionic conductivity of 3.44 × 10⁻⁴ S cm⁻¹ and a tLi⁺ of 0.52. Yet, poor interfacial adhesion between the membrane and the cathode brought about a low specific capacity of 48 mAh g⁻¹. For the reinforced interlocking bilayer membrane, an ionic conductivity of 3.24 × 10⁻⁴ S cm⁻¹ and a tLi⁺ of 0.42 could be achieved. Moreover, the capacity retention reached as high as 80% after 100 cycles (0.2 C, 80 °C). This is because the presence of the epoxy-based interlocking bilayer structure can block the pathway of lithium dendrite puncture effectively. We demonstrate that the unique interlocking bilayer structure is capable of offering a new approach to fabricate a robust SPE for ASSLIBs.

Review on Comparison of Different Energy Storage Technologies Used in Micro-Energy Harvesting, WSNs, Low-Cost Microelectronic Devices: Challenges and Recommendations

This paper reviews energy storage systems, in general, and for specific applications in low-cost micro-energy harvesting (MEH) systems, low-cost microelectronic devices, and wireless sensor networks (WSNs). With the development of electronic gadgets, low-cost microelectronic devices and WSNs, the need for an efficient, light and reliable energy storage device is increased. The current energy storage systems (ESS) have the disadvantages of self-discharging, energy density, life cycles, and cost. The ambient energy resources are the best option as an energy source, but the main challenge in harvesting energy from ambient sources is the instability of the source of energy. Due to the explosion of lithium batteries in many cases, and the pros associated with them, the design of an efficient device, which is more reliable and efficient than conventional batteries, is important. This review paper focused on the issues of the reliability and performance of electrical ESS, and, especially, discussed the technical challenges and suggested solutions for ESS (batteries, supercapacitors, and for a hybrid combination of supercapacitors and batteries) in detail. Nowadays, the main market of batteries is WSNs, but in the last decade, the world's attention has turned toward supercapacitors as a good alternative of batteries. The main advantages of supercapacitors are their light weight, volume, greater life cycle, turbo charging/discharging, high energy density and power density, low cost, easy maintenance, and no pollution. This study reviews supercapacitors as a better alternative of batteries in low-cost electronic devices, WSNs, and MEH systems.

Synthesis and Use of Zwitterion Bearing Sulfonyl(trifluoromethane sylfonyl)imide Anion as Additive for Polymer Electrolytes

In order to improve the electrochemical properties of poly(ethylene oxide), a well-known-solid polymer electrolyte, by adding zwitterion molecules, the synthesis of a new zwitterion (ZN) having imidazolium cation and sulfonyl(trifluoromethane sulfonyl)imide anion is investigated. The addition of different amounts of ZN to the mixture of lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) and poly(ethylene glycol)dimethyl ether (PEGDM) of 1000 g mol−1 does not significantly affect the transition temperature of PEGDM but causes a slight decrease in ionic conductivity of the electrolyte mixtures. However, even with the presence of only 0.05 mole fraction of ZN, the anodic stability of LiTFSI/PEGDM based electrolytes is improved to over 4.5 V vs. Li+/Li at 25 °C. This makes the new synthesized zwitterion a promising electrolyte’s additive for high voltage batteries.