High performance of boehmite/polyacrylonitrile composite nanofiber membrane for polymer lithium-ion battery

Layered double hydroxide based composite core-shell electrospun nanofibers for lead and fluoride filtration from contaminated streams

Coaxial electrospinning was used to synthesize polyacrylonitrile-polyethersulfone (PAN-PES) core-shell nanofibers with magnesium-aluminum layered double hydroxide (Mg-Al LDH) for filtration of lead and fluoride from contaminated streams. Fiber geometry was characterized at a 0.5 mL h-1 flow rate for the core polymer (PES/LDH) and 0.8 mL h-1 flow rate for the shell polymer (PAN), with a potential of 23 kV and a distance of 15-17 cm between the collector and the needle head. A homogeneous fiber shape was achieved using an optimal LDH concentration of 0.7%. The prepared nanofibers served as an ultrafiltration membrane with a permeability of 5 × 10-12 m s-1 Pa-1. The uptake capacity of the produced nanofibers for fluoride and lead was estimated to be 948 mg g-1 and 196 mg g-1, respectively at 298 K as per Langmuir's isotherm model. These fibers exhibited hydrophilic properties and possessed a significant level of porosity. XPS study revealed binding energies of 139.3 eV and 685.2 eV, indicating lead and fluoride uptake by the nanofibers. Ether, sulfone, hydroxyl and nitrile groups found in the nanofibers' shell and core most likely contributed to the lead and fluoride uptake. This facilitated the uptake of both ions on the surface of the nanofibers. In terms of the inhibition effect, fluoride had a stronger masking effect compared with lead in a multicomponent solution (consisting of lead and fluoride). Dynamic vacuum filtration was also investigated using the prepared nanofibers in artificial and real-life feed solutions.

Fabrication of Network Spherical α-Al2O3 and Its Application on the Separator of Lithium-Ion Batteries

Ceramic-coated polyolefin separator technology is considered a simple and effective method for the improvement of lithium-ion battery (LIB) safety. However, the characteristics of ceramic powder can adversely affect the surface structure and ion conductivity of the separators. Therefore, it is crucial to develop a ceramic powder that not only improves the thermal stability of the separators but also enhances ion conductivity. Herein, network spherical α-Al2O3 (N-Al2O3) with a multi-dimensional network pore structure was constructed. Furthermore, N-Al2O3 was applied as a coating to one side of polyethylene (PE) separators, resulting in N-Al2O3-PE separators that exhibit superior thermal stability and enhanced wettability with liquid electrolytes. Notably, the N-Al2O3-PE separators demonstrated exceptional ionic conductivity (0.632 mS cm-1), attributed to the internal multi-dimensional network pore structures of N-Al2O3, which facilitated an interconnected and efficient "highway" for the transport of Li+ ions. As a consequence, LiCoO2/Li half batteries equipped with these N-Al2O3-PE separators showcased remarkable rate and cycling performance. Particularly at high current densities, their discharge capacity and capacity retention rate significantly outperformed those of conventional PE separators.

High electrolyte uptake of MXene integrated membrane separators for Zn-ion batteries

The recent development of separators with high flexibility, high electrolyte uptake, and ionic conductivity for batteries have gained considerable attention. However, studies on composite separators with the aforementioned properties for aqueous electrolytes in Zn-ion batteries are limited. In this research, a polyacrylonitrile (PAN)/bio-based polyurethane (PU)/Ti3C2Tx MXene composite membrane was fabricated using an electrospinning technique. Ti3C2 MXene was embedded in fibers and formed a spindle-like structure. With Ti3C2Tx MXene, the electrolyte uptake and ionic conductivity reached the superior values of 2214% and 3.35 × 10-3 S cm-1, respectively. The composite membrane presented an excellent charge-discharge stability when assembled in a Zn//Zn symmetrical battery. Moreover, the developed separator exhibited a high flexibility and no dimensional and structural changes after heat treatment, which resulted in the high-performance separator for the Zn-ion battery. Overall, the PAN/bio-based PU/Ti3C2Tx MXene composite membrane can be potentially used as a high-performance separator for Zn-ion batteries.

Recent Advances on Materials for Lithium-Ion Batteries

Environmental issues related to energy consumption are mainly associated with the strong dependence on fossil fuels. To solve these issues, renewable energy sources systems have been developed as well as advanced energy storage systems. Batteries are the main storage system related to mobility, and they are applied in devices such as laptops, cell phones, and electric vehicles. Lithium-ion batteries (LIBs) are the most used battery system based on their high specific capacity, long cycle life, and no memory effects. This rapidly evolving field urges for a systematic comparative compilation of the most recent developments on battery technology in order to keep up with the growing number of materials, strategies, and battery performance data, allowing the design of future developments in the field. Thus, this review focuses on the different materials recently developed for the different battery components—anode, cathode, and separator/electrolyte—in order to further improve LIB systems. Moreover, solid polymer electrolytes (SPE) for LIBs are also highlighted. Together with the study of new advanced materials, materials modification by doping or synthesis, the combination of different materials, fillers addition, size manipulation, or the use of high ionic conductor materials are also presented as effective methods to enhance the electrochemical properties of LIBs. Finally, it is also shown that the development of advanced materials is not only focused on improving efficiency but also on the application of more environmentally friendly materials.