Lithium polymer electrolyte rechargeable battery

Recent Advances in Synthesis and Applications of Single-Atom Catalysts for Rechargeable Batteries

The rapid development of flexible and wearable optoelectronic devices, demanding the superior, reliable, and ultra-long cycling energy storage systems. But poor performances of electrode materials used in energy devices are main obstacles. Recently, single-atom catalysts (SACs) are considered as emerging and potential candidates as electrode materials for battery devices. Herein, we have discussed the recent methods for the fabrication of SACs for rechargeable metal-air batteries, metal-CO₂ batteries, metal-sulfur batteries, and other batteries, following the recent advances in assembling and performance of these batteries by using SACs as electrode materials. The role of SACs to solve the bottle-neck problems of these energy storage devices and future perspectives are also discussed.

Single-Atom Catalytic Materials for Advanced Battery Systems

Advanced battery systems with high energy density have attracted enormous research enthusiasm with potential for portable electronics, electrical vehicles, and grid-scale systems. To enhance the performance of conversion-type batteries, various catalytic materials are developed, including metals and transition-metal dichalcogenides (TMDs). Metals are highly conductive with catalytic effects, but bulk structures with low surface area result in low atom utilization, and high chemical reactivity induces unfavorable dendrite effects. TMDs present chemical adsorption with active species and catalytic activity promotes conversion processes, suppressing shuttle effect and improving energy density. But they suffer from inferior conductivity compared with metal, and limited sites mainly concentrate on edges and defects. Single-atom materials with atomic sizes, good conductivity, and individual sites are promising candidates for advanced batteries because of a large atom utilization, unsaturated coordination, and unique electronic structure. Single-atom sites with high activity chemically trap intermediates to suppress shuttle effects and facilitate electron transfer and redox reactions for achieving high capacity, rate capability, and conversion efficiency. Herein, single-atom catalytic electrodes design for advanced battery systems is addressed. Major challenges and promising strategies concerning electrochemical reactions, theoretical model, and in situ characterization are discussed to shed light on future research of single-atom material-based energy systems.

Surface Reinforcing Balloon Trick-Inspired Separator/Li Metal Integrated Assembly To Improve the Electrochemical Performance of Li Metal Batteries

Li metal experiences significant morphological changes during operation, resulting in rapid electrochemical performance degradation. In this study, a traditional balloon trick is applied to the Li metal surface to release mechanical stress and hinder morphological changes during operation. Polymer separators directly attach to the Li metal surface using a polymeric adhesive to fabricate a separator/Li metal integrated assembly. The separator/Li metal assembly improves not only the electrochemical performance but also safety issues related to Li metal anodes. This approach has three main advantages: (i) Li metal surface stabilization. The separator/Li metal assembly mechanically stabilize the Li metal surface, resulting in improved rate capability and cycle performance [85.0% of initial discharge capacity (90.2 mAh g^-1) at a 7C condition for rate capability and 87.6% of discharge capacity (95.5 mAh g^-1) at the 220th cycle] compared with the bare Li metal without separator integration [82.6% of initial discharge capacity (84.5 mAh g^-1) at a 3C condition for rate capability and 58.0% of discharge capacity (62.6 mAh g^-1) at the 120th cycle]. (ii) Suitability for high energy density battery implementation. The thickness of the polymeric adhesive is less than 1 μm, which is one-tenth of the coating layer of conventional thermally stable separators, but exhibits similar thermal shrinkage characteristics (0% shrinkage at 140 °C for 30 min). By reducing the thickness of inactive components, a larger volume of active material can be loaded into the battery system to increase the energy density of the battery. (iii) Simple process for mass production. The separator/Li metal integration process ("stick" and "dry") is very simple and can be easily applicable across industries.

Temperature dependence of ion transport in dilute tetrabutylammonium triflate-acetate solutions and self-diffusion in pure acetate liquids

Conductivities and static dielectric constants for 0.0055 M tetrabutylammonium trifluoromethanesulfonate in n-butyl acetate, n-pentyl acetate, n-hexyl acetate, n-octyl acetate, and n-decyl acetate have been collected over the temperature range of 0-80 °C. Self-diffusion coefficients and static dielectric constants of pure acetates were obtained over the same temperature range. Both temperature-dependent diffusion coefficients and ionic conductivities of these pure acetates and dilute acetate solutions can be accurately described by the compensated Arrhenius formalism. Activation energies were calculated from compensated Arrhenius plots for both conductivity and diffusion data. Activation energies are higher for conductivity data of 0.0055 M TbaTf-acetates compared to diffusion data of pure acetates. The plot of the exponential prefactor versus the dielectric constant yields a single master curve for both conductivity and diffusion data. These data support the argument that mass and charge transport are thermally activated processes in the acetates, as previously observed in alcohol-based electrolytes.

New nanomaterials for light weight lithium batteries

Technological improvements, allowing to manipulate and investigate the properties of nanomaterials, are nowadays changing the approach to the energy storage and power supply vision. Modern nanoscale techniques led the market in the realization of nanostructured inorganic and organic materials increasing the efficiency of different devices, like lithium batteries, one of the most promising energy storage elements, obtaining everyday higher values of capacity, cyclability and environmental resistance. Each part of the battery, the anode, the cathode and the electrolyte, are here described analyzing the nanomaterials used for their realization.

Battery separators

The ideal battery separator would be infinitesimally thin, offer no resistance to ionic transport in electrolytes, provide infinite resistance to electronic conductivity for isolation of electrodes, be highly tortuous to prevent dendritic growths, and be inert to chemical reactions. Unfortunately, in the real world the ideal case does not exist. Real world separators are electronically insulating membranes whose ionic resistivity is brought to the desired range by manipulating the membranes thickness and porosity. It is clear that no single separator satisfies all the needs of battery designers, and compromises have to be made. It is ultimately the application that decides which separator is most suitable. We hope that this paper will be a useful tool and will help the battery manufacturers in selecting the most appropriate separators for their batteries and respective applications. The information provided is purely technical and does not include other very important parameters, such as cost of production, availability, and long-term stability. There has been a continued demand for thinner battery separators to increase battery power and capacity. This has been especially true for lithiumion batteries used in portable electronics. However, it is very important to ensure the continued safety of batteries, and this is where the role of the separator is greatest. Thus, it is essential to optimize all the components of battery to improve the performance while maintaining the safety of these cells. Separator manufacturers should work along with the battery manufacturers to create the next generation of batteries with increased reliability and performance, but always keeping safety in mind. This paper has attempted to present a comprehensive review of literature on separators used in various batteries. It is evident that a wide variety of separators are available and that they are critical components in batteries. In many cases, the separator is one of the major factors limiting the life and/or performance of batteries. Consequently, development of new improved separators would be very beneficial for the advanced high capacity batteries.

Ion solvation and association in LiClO4/sulfolane solution: a vibrational spectroscopic and molecular orbital study

Solvation interaction and ion association in solutions of lithium perchlorate/sulfolane have been studied by using infrared and Raman spectra as a function of concentration of lithium perchlorate. The band changes of antisymmetric OSO stretch, antisymmetric CSC stretch, -SO2 wag and twist suggest that there is an interaction between Li+ and sulfolane molecules, and the site of solvation is the oxygen atom of -SO2 group. The molecular orbital calculation supports this suggestion. On the other hand, the apparent solvation number was calculated, and the band fitting for the ClO4- band reveals the presence of contact ion pair, solvent separated ion pair and free ClO4- anion in the concentrated solutions.