Understanding the Electrode/Electrolyte Interface Layer on the Li-Rich Nickel Manganese Cobalt Layered Oxide Cathode by XPS.

Layered lithium-rich nickel manganese cobalt oxide (LR-NMC) represents one of the most promising cathode materials for application in high energy density lithium-ion batteries. The extraordinary capacity delivered derives from a combination of both cationic and anionic redox processes. However, the latter ones lead to oxygen evolution which triggers structural degradation and electrode/electrolyte interface (EEI) instability that hinders the use of LR-NMC in practical application.

Water Purification and Microplastics Removal Using Magnetic Polyoxometalate-Supported Ionic Liquid Phases (magPOM-SILPs).

Filtration is an established water-purification technology. However, due to low flow rates, the filtration of large volumes of water is often not practical. Herein, we report an alternative purification approach in which a magnetic nanoparticle composite is used to remove organic, inorganic, microbial, and microplastics pollutants from water.

Composition Modulation of Ionic Liquid Hybrid Electrolyte for 5 V Lithium-Ion Batteries.

Electrolyte is a key component in high-voltage lithium-ion batteries (LIBs). Bis(trifluoromethanesulfonyl)imide-based ionic liquid (IL)/organic carbonate hybrid electrolytes have been a research focus owing to their excellent balance of safety and ionic conductivity. Nevertheless, corrosion of Al current collectors at high potentials usually happens for this kind of electrolyte.

Surface chemistry and electrochemistry of an ionic liquid and lithium on LiTiO(111)-A model study of the anode|electrolyte interface.

Aiming at a detailed molecular understanding of the initial stage of the solid|electrolyte interphase (SEI) formation in Li-ion batteries, we have investigated the interaction of the battery-relevant ionic liquid (IL) 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMP][TFSI]) (solvent/electrolyte) and Li (Li ion shuttle) on well-defined Li-poor LiTiO(111) and Li-rich LiTiO(111) surfaces/electrodes in a combined surface science and electrochemical model study. X-ray photoelectron spectroscopy (XPS) measurements reveal that postdeposition of Li under ultrahigh vacuum (UHV) conditions on a Li-poor LiTiO(111) surface precovered with a molecularly adsorbed [BMP][TFSI] adlayer leads to little IL decomposition at 80 and 300 K. We assume that most of the Li diffuses through the IL adlayer and rapidly inserts into the LiTiO(111) bulk.

Design and Tuning of the Electrochemical Properties of Vanadium-Based Cation-Disordered Rock-Salt Oxide Positive Electrode Material for Lithium-Ion Batteries.

Disordered rock-salt compounds are becoming increasingly important due to their potential as high-capacity positive electrode materials for lithium-ion batteries. Thereby, a significant number of studies have focused on increasing the accessible Li capacity, but studies to manipulate the electrochemical potential are limited. This work explores the effect of transition-metal substitution on the electrochemistry of ternary disordered rock-salt-type compounds with LiMVO stoichiometry (M = Mn, Fe, Co) directly synthesized through mechanochemistry.

A More Sustainable and Cheaper One-Pot Route for the Synthesis of Hydrophobic Ionic Liquids for Electrolyte Applications.

An innovative one-pot synthetic process that uses water as the only processing solvent was used to obtain ionic liquids (ILs) in a yield of approximately 95 mol % and purity greater than 99.3 wt % (<2 ppm each of lithium, bromide and moisture) in a processing time of 1 h. Since no heating is needed for carrying out the reaction and no purification through sorbents is required, energy, time and chemicals can be saved to minimize waste production.

Grand Canonical ReaxFF Molecular Dynamics Simulations for Catalytic Reactions.

In order to study the time-dependent behavior of catalytic systems during operation, we have developed a grand canonical molecular dynamics approach based on the ReaxFF reactive force-field framework. After describing the details of the implementation, the capabilities of this method are demonstrated by studying the gas-phase water formation from oxygen and hydrogen on platinum catalysts during the steady state where we discuss the effects of the surface structure as well as the importance of kinetics. The approach presented here can be extended to other dynamic (catalytic) systems, providing a framework for exploring catalytic and electrocatalytic processes, in particular, allowing studies on the effects of reaction conditions on a system's behavior, characteristics, and stability.

Difference in Electrochemical Mechanism of SnO Conversion in Lithium-Ion and Sodium-Ion Batteries: Combined in Operando and Ex Situ XAS Investigations.

Conversion and alloying type negative electrodes attracted huge attention in the present research on lithium/sodium-ion batteries (LIBs/SIBs) due to the high capacity delivered. Among these, SnO is investigated intensively in LIBs due to high cyclability, low reaction potential, cost-effectiveness, and environmental friendliness. Most of the LIB electrodes are explored in SIBs too due to expected similar electrochemical performance.

Insight into Sulfur Confined in Ultramicroporous Carbon.

Here, we provide a deeper insight into the state of sulfur confined in ultramicroporous carbon (UMC) and clarify its electrochemical reaction mechanism with lithium by corroborating the results obtained using various experimental techniques, such as X-ray photoelectron spectroscopy, electron energy loss spectroscopy, Raman spectroscopy, and electrochemical impedance spectroscopy. In combination, these results indicate that sulfur in UMC exists as linear polymeric sulfur rather than smaller allotropes. The electrochemical reactivity of lithium with sulfur confined in UMC (pore size ≤0.

Calcined chicken eggshell electrode for battery and supercapacitor applications.

Biowaste eggshell can be used as a cathode while in its calcined form and it is found to be suitable as an anode in an electrochemical cell. This not only enables energy to be stored reversibly but also achieves waste management and sustainability goals by redirecting material away from landfill. Biowaste eggshell comprises 94% calcium carbonate (CaCO; calcite), an attractive divalent ion source as a viable option for energy storage.

Solvent-Controlled Polymerization of Molecular Strontium Vanadate Monomers into 1D Strontium Vanadium Oxide Chains.

We report the polymerization of a solvent-stabilized molecular strontium vanadium oxide monomer into infinite 1D chains. Supramolecular polymerization is triggered by controlled solvent-exchange, which leads to oligomer and polymer formation. Mechanistic insights into the chain formation were obtained by solid-state, solution, and gas-phase studies.

A Crosslinked Polyethyleneglycol Solid Electrolyte Dissolving Lithium Bis(trifluoromethylsulfonyl)imide for Rechargeable Lithium Batteries.

Replacing liquid electrolytes with solid ones can provide advantages in safety, and all-solid-state batteries with solid electrolytes are proposed to solve the issue of the formation of lithium dendrites. In this study, a crosslinked polymer composite solid electrolyte was presented, which enabled the construction of lithium batteries with outstanding electrochemical behavior over long-term cycling. The crosslinked polymeric host was synthesized through polymerization of the terminal amines of O,O-bis(2-aminopropyl) polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol and terminal epoxy groups of bisphenol A diglycidyl ether at 90 °C and provided an amorphous matrix for Li dissolution.

Mechanism Study of Carbon Coating Effects on Conversion-Type Anode Materials in Lithium-Ion Batteries: Case Study of ZnMnO and ZnO-MnO Composites.

The carbon coating strategy is intensively used in the modification of conversion-type anode materials to improve their cycling stability and rate capability. Thus, it is necessary to elucidate the modification mechanism induced by carbon coating. For this purpose, bare ZnMnO, carbon-derivative-coated ZnMnO, and carbon-coated ZnO-MnO composite materials have been synthesized and investigated in-depth.

Halide-Based Materials and Chemistry for Rechargeable Batteries.

Rechargeable batteries are considered one of the most effective energy storage technologies to bridge the production and consumption of renewable energy. The further development of rechargeable batteries with characteristics such as high energy density, low cost, safety, and a long cycle life is required to meet the ever-increasing energy-storage demands. This Review highlights the progress achieved with halide-based materials in rechargeable batteries, including the use of halide electrodes, bulk and/or surface halogen-doping of electrodes, electrolyte design, and additives that enable fast ion shuttling and stable electrode/electrolyte interfaces, as well as realization of new battery chemistry.

Alloying Reaction Confinement Enables High-Capacity and Stable Anodes for Lithium-Ion Batteries.

The current insertion anode chemistries are approaching their capacity limits; thus, alloying reaction anode materials with high theoretical specific capacity are investigated as potential alternatives for lithium-ion batteries. However, their performance is far from being satisfactory because of the large volume change and severe capacity decay that occurs upon lithium alloying and dealloying processes. To address these problems, we propose and demonstrate a versatile strategy that makes use of the electronic reaction confinement the synthesis of ultrasmall Ge nanoparticles (10 nm) uniformly confined in a matrix of larger spherical carbon particles (Ge⊂C spheres).

Concentrated Ionic-Liquid-Based Electrolytes for High-Voltage Lithium Batteries with Improved Performance at Room Temperature.

Ionic liquids (ILs) have been widely explored as alternative electrolytes to combat the safety issues associated with conventional organic electrolytes. However, hindered by their relatively high viscosity, the electrochemical performances of IL-based cells are generally assessed at medium-to-high temperature and limited cycling rate. A suitable combination of alkoxy-functionalized cations with asymmetric imide anions can effectively lower the lattice energy and improve the fluidity of the IL material.

Toward Stable Electrode/Electrolyte Interface of P2-Layered Oxide for Rechargeable Na-Ion Batteries.

The electrochemical properties of P2-NaMnFeTiO layered oxide, which is a promising cathode material for rechargeable Na-ion batteries (NIBs), are evaluated with an optimized in-house ionic liquid (IL)-based electrolyte, and its performance is compared with that using carbonate-based electrolyte. The IL-based system reveals better electrochemical performance at room temperature than the carbonate electrolyte-based one at 0.1C and 1C, especially in terms of cycling stability, with a 97% capacity retention after 100 deep cycles (0.

Porous N- and S-doped carbon-carbon composite electrodes by soft-templating for redox flow batteries.

Highly porous carbon-carbon composite electrodes for the implementation in redox flow battery systems have been synthesized by a novel soft-templating approach. A PAN-based carbon felt was embedded into a solution containing a phenolic resin, a nitrogen source (pyrrole-2-carboxaldehyde) and a sulfur source (2-thiophenecarboxaldehyde), as well as a triblock copolymer (Pluronic F-127) acting as the structure-directing agent. By this strategy, highly porous carbon phase co-doped with nitrogen and sulfur was obtained inside the macroporous carbon felt.

Enhancing the Electrochemical Performance of LiNiCoMnO by VO/LiVO Coating.

Despite layered LiNiCoMnO having drawn much attention for their high capacity and high energy density, they still endure strong capacity decay upon prolonged cycling and high C-rates, primarily due to sluggish Li and charge-transfer kinetics and detrimental parasitic reactions with the electrolyte. To address these issues, application of a surface-coating layer made of VO/LiVO on LiNiCoMnO (V-NCM) is pursued. Benefiting from the ionic conductivity of LiVO and the electronic conductivity of VO, resulting in both enhanced Li diffusion and charge-transfer kinetics, the coated material offers significantly improved C-rate capability.

A Lithium-Free Energy-Storage Device Based on an Alkyne-Substituted-Porphyrin Complex.

Porphyrin complexes are well-known for their application in solar-cell systems and as catalysts; however, their use in electrochemical energy-storage applications has scarcely been studied. Here, a tetra-alkenyl-substituted [5,10,15,20-tetra(ethynyl)porphinato]copper(II) (CuTEP) complex was used as anode material in a high-performance lithium-free CuTEP/PP TFSI/graphite cell [PP TFSI=1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide]. Thereby, the influence of size and morphology on the electrochemical performance of the cell was thoroughly investigated.

The electrochemical double layer and its impedance behavior in lithium-ion batteries.

Interfacial reaction and transport processes contribute crucially to the overall performance and impedance of electrochemical systems. The influence of the electrochemical double layer and the interfacial reactions on the impedance of lithium intercalation batteries is investigated with a modeling approach. Our generic theory for charge and electron transfer reactions at electrified interfaces and its simplified adaptation, a reduced interface model, are compared with the standard for electrochemical interface modeling, the Butler-Volmer ansatz, in terms of numerically simulated impedance spectra.

Direct Conversion of CO to Multi-Layer Graphene using Cu-Pd Alloys.

A straightforward one-step process was developed, in which CO gas is directly converted into multi-layer graphene via atmospheric pressure chemical vapor deposition (APCVD). A bimetallic alloy film based on Cu and Pd was employed as the catalyst and substrate. In this study, we found that the quantity of Cu required for the CO conversion process is high (>82 at %).

Ionic Liquid-Based Electrolytes for Sodium-Ion Batteries: Tuning Properties To Enhance the Electrochemical Performance of Manganese-Based Layered Oxide Cathode.

Ionic liquids (ILs) are considered as appealing alternative electrolytes for application in rechargeable batteries, including next-generation sodium-ion batteries, because of their safe and eco-friendly nature, resulting from their extremely low volatility. In this work, two groups of advanced pyrrolidinium-based IL electrolytes are concerned, made by mixing sodium bis(fluorosulfonyl)imide (NaFSI) or sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) salts salts with N-methyl- N-propylpyrrolidinium bis(fluorosulfonyl)imide (PyrFSI), N-butyl- N-methylpyrrolidinium bis(fluorosulfonyl)imide (PyrFSI), and N-butyl- N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PyrFSI). The characterization of eight different electrolytes, including single anion electrolytes and binary anion mixtures, in terms of thermal properties, density, viscosity, and conductivity, as well as electrochemical stability window and cycling performance in room-temperature sodium cells, is reported here.

Interface in Solid-State Lithium Battery: Challenges, Progress, and Outlook.

All-solid-state batteries (ASSBs) based on inorganic solid electrolytes promise improved safety, higher energy density, longer cycle life, and lower cost than conventional Li-ion batteries. However, their practical application is hampered by the high resistance arising at the solid-solid electrode-electrolyte interface. Although the exact mechanism of this interface resistance has not been fully understood, various chemical, electrochemical, and chemo-mechanical processes govern the charge transfer phenomenon at the interface.

Role of Manganese in Lithium- and Manganese-Rich Layered Oxides Cathodes.

Lithium-rich transition-metal-oxide cathodes are among the most promising materials for next generation lithium-ion-batteries because they operate at high voltages and deliver high capacities. However, their cycle-life remains limited, and individual roles of the transition-metals are still not fully understood. Using bulk-sensitive X-ray absorption and emission spectroscopy on Li[LiNiMnCo]O, we inspect the behavior of Mn, generally considered inert upon the electrochemical process.