Recent Advances on Materials for Lithium-Ion Batteries

Mixed Conducting Oxide Coating for Lithium Batteries

Thin, uniform, and conformal coatings on the active electrode materials are gaining more importance to mitigate degradation mechanisms in lithium-ion batteries. To avoid polarization of the electrode, mixed conductors are of crucial importance. Atomic layer deposition (ALD) is employed in this work to provide superior uniformity, conformality, and the ability to precisely control the stoichiometry and thickness of the desired coating materials. We provide experimental and computational guidelines for the need of mixed electronic and ionic conducting coating materials, especially in the case where highly uniform and conformal coatings are achieved. We report promising results for ALD-deposited protective films achieved by doping fluorine (F) into a lithium vanadate coating. The F-doped lithium vanadate coating at the optimal doping level exhibits an electrical conductivity of 1.2 × 10-5 S·cm-1. Density functional theory calculations corroborate enhanced mixed electronic and ionic conduction in F-doped lithium vanadate through band structure analysis and climbing-image nudge elastic band (CI-NEB) calculations. It has been demonstrated that the experimentally determined optimal doping concentration aligns well with that predicted by density functional theory calculations. CI-NEB calculations have shown that the activation energy for lithium-ion transport was the lowest for optimally doped lithium vanadate.

Recent Progress on the Synthesis, Morphological Topography, and Battery Applications of Polypyrrole-Based Nanocomposites

Polypyrrole (PPy)-based nanocomposite materials are of great interest to the scientific community owing to their usefulness in designing state-of-the-art industrial applications, such as fuel cells, catalysts and sensors, energy devices, and especially batteries. However, the commercialization of these materials has not yet reached a satisfactory level of implementation. More research is required for the design and synthesis of PPy-based composite materials for numerous types of battery applications. Due to the rising demand for environmentally friendly, cost-effective, and sustainable energy, battery applications are a significant solution to the energy crisis, utilizing suitable materials like PPy-based composites. Among the conducting polymers, PPy is considered an important class of materials owing to their ease of synthesis, low cost, environmentally friendly nature, and so on. In this context, PPy-based nanocomposites may be very promising due to their nanostructural properties and distinct morphological topography, which are vital concerns for their applications for battery applications. Such features of PPy-based nanocomposites make them particularly promising for next-generation electrode materials. However, the design and fabrication of appropriate PPy-based nanocomposites for battery applications is still a challenging area of research. This review paper describes the current progress on the synthesizing of PPy-based composites for battery applications along with their morphological topography. We discussed here the recent progress on the synthesis of different PPy-based composites, including PPy/S, PPy/MnOx, MWCNT/PPy, V2O5/PPy, Cl-doped PPy/rGO, and Fe/α-MnO2@PPy composites, by a polymerization approach for numerous battery applications. The insights presented in this review aim to provide a comprehensive reference for the future development of PPy-based composites in battery technology.

Thermal Degradation Kinetics Analysis of Polymer Composite Electrolyte Membranes of PEVOH and PBT Nano Fiber

The thermal degradation kinetics of high-performance polymer composite electrolyte membranes were investigated by thermal gravimetric analysis in this study. The novel porous polymer composite membranes were fabricated by crosslinking poly (ethylene-co-vinyl alcohol) (EVOH) with polybutylene terephthalate (PBT) nano fiber. The PBT nano-scale fiber non-woven cloth was first prepared by the electrospinning method to form a labyrinth-like structure, and the crosslinking was carried out by filtering it through a solution of EVOH and crosslinking agent triallylamine using the Porcelain Buchner funnel vacuum filtration method. The PBT-EVOH composite membranes with various crosslinking agent ratios and ethylene carbonate/dimethyl carbonate (EC/DMC) immersion times were investigated for their thermal stability and ionic conductivity. The results showed that the higher crosslinking agent content would lower the crystallinity and enhance thermal stability. The thermal degradation activation energy was dramatically increased from 125 kJ/mol to 340 kJ/mol for the 1.5% crosslinking agent content sample at 80% conversion. The triallylamine crosslinking agent was indeed effective in improving thermal degradation resistivity. The best ionic conductivity of the polymer composite membranes was exhibited at 5.04 × 10-3 S cm-1 using the optimal weight ratio of EVOH/PBT composite controlled at 1/2. On the other hand, the EC/DMC immersion time was more effective in controlling the Rb value, thus the ionic conductivity of the membranes. A higher immersion time, such as 48 h, not only gave higher conductivity data but also provided more stable results. The triallylamine crosslinking agent improved the membrane ionic conductivity by about 22%.

Silk fibroin and sericin polymer blends for sustainable battery separators

Natural polymers are a promising alternative for reducing the environmental impact of batteries. For this reason, it is still necessary to study their behavior and implement its use in these devices, especially in separator membranes. This work reports on new separator membranes based on silk fibroin (SF) and silk sericin (SS) prepared by salt leaching method. The effect of the different SS relative content on the physiochemical properties of the membranes and on the electrochemical performance of the corresponding batteries with lithium iron phosphate (LFP) as cathodes has been reported. It is observed that the increasing of SS content leads to a decrease of the overall crystallinity of the membranes. All SF/SS membranes presented a well-defined porosity above 75% with a uniform distribution of interconnected micropores. The electrolyte uptake and the ionic conductivity are dependent on the relative SS content. The addition of 10 wt% of SS into SF membranes, induce a high ionic conductivity of 4.09 mS.cm^-1 and high lithium transference number (0.52), due to the improvement of the Li⁺ ions conduction paths within the blended structure. Charge/discharge tests performed in Lithium/C-LFP half-cells reveal a discharge capacity of 85 mAh.g^-1 at 2C after 100 cycles for batteries with a SF/SS separator, containing a 10 wt% of SS, which suggests a stabilizing effect of Sericin on discharge capacity. Further, a 50% and 35% of capacity of retention and capacity fade, respectively, is observed. The presented SF/SS membrane show high electrochemical stability, being suitable for implementation in a next generation of sustainable battery systems. This could allow the SS valorization considering that 150,000 tons of SS are abandoned each year, reducing the contamination of environmental effluents.

The Second Generation Electromobility in Polish Urban Public Transport: The Factors and Mechanisms of Spatial Development

One of the key challenges on the road to sustainable mobility is the development of low/zero emission urban public transport (UPT). This is crucial in order to meet environmental requirements aiming at reducing greenhouse gas (GHG) emission. In some countries (e.g., Poland) reduction of air pollution is also an important reason behind the implementation of low/zero emission UPT. The aim of this study is to investigate the factors and mechanisms influencing the development of modern electromobility in Polish UPT. We have examined all 242 UPT systems in the country in terms of the characteristics of the relevant urban municipalities, such as size, economic prosperity, level of human and social capital, development paths of urban public transport in the long term as well as the institutional context and proximity and connections to other cities with experience in electromobility. Classification and statistical methods are used based on a variety of approaches, as assigning a score to various preliminarily identified indicators or applying correlation between quantities to verify the formulated hypotheses. Our analysis demonstrates that electromobility adoption is the result of a combination of favourable economic, urban, social and technological characteristic features of a given city. Zero or low emission buses are more common in large cities which are highly positioned in urban hierarchy, economically sound and which are characterized by a well-developed tertiary economy as well as by high human capital. An additional factor that positively influences the implementation of electromobility—in particular at the very first stage—is proximity to the location of low emission bus producers. The leadership in modern electromobility can be understood as part of a broader, proactive development policy of the cities aimed at improving the quality of life of their residents. This is especially important in medium-sized towns where utilizing electric vehicles can be an instrument to maintain or even develop their role and status. The results of the article may provide a basis for creating sustainable urban policies, especially sustainable mobility and improving environmental quality.