PFAS-Free Energy Storage: Investigating Alternatives for Lithium-Ion Batteries.

The class-wide restriction proposal on perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the European Union is expected to affect a wide range of commercial sectors, including the lithium-ion battery (LIB) industry, where both polymeric and low molecular weight PFAS are used. The PFAS restriction dossiers currently state that there is weak evidence for viable alternatives to the use of PFAS in LIBs. In this Perspective, we summarize both the peer-reviewed literature and expert opinions from academia and industry to verify the legitimacy of the claims surrounding the lack of alternatives.

Tailoring superstructure units for improved oxygen redox activity in Li-rich layered oxide battery's positive electrodes.

The high-voltage oxygen redox activity of Li-rich layered oxides enables additional capacity beyond conventional transition metal (TM) redox contributions and drives the development of positive electrode active materials in secondary Li-based batteries. However, Li-rich layered oxides often face voltage decay during battery operation. In particular, although Li-rich positive electrode active materials with a high nickel content demonstrate improved voltage stability, they suffer from poor discharge capacity.

Towards Sustainable Direct Recycling: Unraveling Structural Degradation Induced by Thermal Pretreatment of Lithium-Ion Battery Electrodes.

As the demand for lithium-ion batteries (LIBs) continues to increase, there is a growing focus on recycling these battery wastes. Among the existing recycling methods, direct recycling is considered a promising approach, because it allows waste to be returned directly to production. One crucial step in this process is the pretreatment, which involves separating the active materials from the current collector.

Development of in situ high resolution NMR: Proof-of-principle for a new (spinning) cylindrical mini-pellet approach applied to a Lithium ion battery.

Solid-state nuclear magnetic resonance (ssNMR) spectroscopy is a powerful technique for characterizing the local structure and dynamics of battery and other materials. It has been widely used to investigate bulk electrode compounds, electrolytes, and interfaces. Beside common ex situ investigations, in situ and operando techniques have gained considerable importance for understanding the reaction mechanisms and cell degradation of electrochemical cells.

Systematic Study of the Multiple Variables Involved in VAlC Acid-Based Etching Processes, a Key Step in MXene Synthesis.

The realization of the broad range of application of MXenes relies on the successful and reproducible synthesis of quality materials of tailored properties. To date, most MXenes have been produced making use of acid-based etching methods, yet an in-depth understanding of etching processes is lacking. Herein, we have engaged in a comprehensive study of the multiple variables involved in the synthesis of VCT with focus on the properties of etched materials.

Impact of Iodine Electrodeposition on Nanoporous Carbon Electrode Determined by EQCM, XPS and In Situ Raman Spectroscopy.

The charging of nanoporous carbon via electrodeposition of solid iodine from iodide-based electrolyte is an efficient and ecofriendly method to produce battery cathodes. Here, the interactions at the carbon/iodine interface from first contact with the aqueous electrolyte to the electrochemical polarization conditions in a hybrid cell are investigated by a combination of in situ and ex situ methods. EQCM investigations confirm the flushing out of water from the pores during iodine formation at the positive electrode.

Universal and efficient extraction of lithium for lithium-ion battery recycling using mechanochemistry.

The increasing lithium-ion battery production calls for profitable and ecologically benign technologies for their recycling. Unfortunately, all used recycling technologies are always associated with large energy consumption and utilization of corrosive reagents, which creates a risk to the environment. Herein we report a highly efficient mechanochemically induced acid-free process for recycling Li from cathode materials of different chemistries such as LiCoO, LiMnO, Li(CoNiMn)O, and LiFePO.

Synergy of cations in high entropy oxide lithium ion battery anode.

High entropy oxides (HEOs) with chemically disordered multi-cation structure attract intensive interest as negative electrode materials for battery applications. The outstanding electrochemical performance has been attributed to the high-entropy stabilization and the so-called 'cocktail effect'. However, the configurational entropy of the HEO, which is thermodynamically only metastable at room-temperature, is insufficient to drive the structural reversibility during conversion-type battery reaction, and the 'cocktail effect' has not been explained thus far.

New Insight into Desodiation/Sodiation Mechanism of MoS: Sodium Insertion in Amorphous Mo-S Clusters.

Molybdenum disulfide (MoS) is a promising anode material for sodium batteries due to its high theoretical capacity. While significantly improved electrochemical performance has been achieved, the reaction mechanism is still equivocal. Herein, we applied electron pair distribution function and X-ray absorption spectroscopy to investigate the desodiation/sodiation mechanism of MoS electrodes.

Study of the Lithium Storage Mechanism of N-Doped Carbon-Modified Cu S Electrodes for Lithium-Ion Batteries.

Owing to their high specific capacity and abundant reserve, Cu S compounds are promising electrode materials for lithium-ion batteries (LIBs). Carbon compositing could stabilize the Cu S structure and repress capacity fading during the electrochemical cycling, but the corresponding Li storage mechanism and stabilization effect should be further clarified. In this study, nanoscale Cu S was synthesized by CuS co-precipitation and thermal reduction with polyelectrolytes.

Probing Sulfur Deposition onto Carbon Nanomaterials from Aqueous, Elemental Sulfur Sols for Lithium-Sulfur Batteries.

Sulfur cathodes for lithium-sulfur batteries often rely on integrating sulfur with high surface area carbonaceous materials. Nanoscale mixing is typically achieved by a lengthy, high-temperature melt imbibition approach that employs carbon nanomaterials in an aggregated solid form. In this work, we present a simple strategy to coat carbon nanomaterials with sulfur in a cost-effective, room-temperature process using inexpensive elemental sulfur.

Elucidating the Mechanism of Li Insertion into FeS/Carbon Synchrotron Studies.

The detailed understanding of kinetic and phase dynamics taking place in lithium-ion batteries (LIBs) is crucial for optimizing their properties. It was previously reported that FeS/C nanocomposites display a superior performance as anode materials in LIBs. However, the underlying lithium storage mechanism was not entirely understood during the 1st cycle.

Exploring the Reversibility of Phase Transformations in Aluminum Anodes through Operando Light Microscopy and Stress Analysis.

Aluminum is well-known to possess attractive properties for possible use as an anode material in Li-ion batteries (LIBs), but effort is still needed to understand how and why it degrades. Herein, investigations of the delithiation and the re-lithiation processes in Al thin films using an established operando light microscopic platform are pursued. Operando videos highlight that the extraction of Li from the β phase (LiAl) is accompanied by fracture and crack formation leading to the detachment of the α phase (Al) from the rest of the electrode.

Benefits of Organo-Aqueous Binary Solvents for Redox Supercapacitors Based on Polyoxometalates.

A novel redox electrolyte is proposed based on organo-aqueous solvent and a polyoxometalate (POM) redox moiety. The presence of dimethyl sulfoxide (DMSO) plays multiple roles in this system. Firstly, it enhances the cathodic electrochemical stability window by shifting the H evolution to lower potentials with respect to pure aqueous systems; secondly, it improves the reversibility of the redox reaction of the PWO anion at low potentials.

Redox-inactive ions control the redox-activity of molecular vanadium oxides.

Polyoxometalates are key materials for energy conversion and storage due to their unique chemical tunability and electrochemical reactivity. Herein, we report that functionalization of molecular vanadium oxides, polyoxovanadates, with redox-inert Ca cations leads to a significant increase in their electron storage capabilities. The electrochemical performance of the Ca-functionalized dodecavanadate [CaVOCl(DMF)] (= ) was thus compared with that of the precursor compound (HNMe)[VOCl] (= ).

Effect of Continuous Capacity Rising Performed by FeS/Fe C/C Composite Electrodes for Lithium-Ion Batteries.

FeS-based composites are sustainable conversion electrode materials for lithium-ion batteries, combining features like low cost, environmental friendliness, and high capacities. However, they suffer from fast capacity decay and low electron conductivity. Herein, novel insights into a surprising phenomenon of this material are provided.

Improvement of the Cycling Performance of Aluminum Anodes through Operando Light Microscopy and Kinetic Analysis.

Aluminum is an attractive anode material for lithium-ion batteries (LIBs) owing to its low cost, light weight, and high specific capacity. However, utilization of Al-based anodes is significantly limited by drastic capacity fading during cycling. Herein, a systematic study is performed to investigate the kinetics of electrochemical lithiation of Al thin films to understand the mechanisms governing the phase transformation, by using an operando light microscopy platform.

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.

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.

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.

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.

Can Metallic Sodium Electrodes Affect the Electrochemistry of Sodium-Ion Batteries? Reactivity Issues and Perspectives.

Sodium-ion batteries (NIBs) are promising energy-storage devices with advantages such as low cost and highly abundant raw materials. To probe the electrochemical properties of NIBs, sodium metal is most frequently applied as the reference and/or counter electrode in state-of-the-art literature. However, the high reactivity of the sodium metal and its impact on the electrochemical performance is usually neglected.

High-Entropy Oxides: Fundamental Aspects and Electrochemical Properties.

High-entropy materials, especially high-entropy alloys and oxides, have gained significant interest over the years due to their unique structural characteristics and correlated possibilities for tailoring of functional properties. The developments in the area of high-entropy oxides are highlighted here, with emphasis placed on their fundamental understanding, including entropy-dominated phase-stabilization effects and prospective applications, e.g.

In Operando Synchrotron Diffraction and in Operando X-ray Absorption Spectroscopy Investigations of Orthorhombic VO Nanowires as Cathode Materials for Mg-Ion Batteries.

Orthorhombic VO nanowires were successfully synthesized via a hydrothermal method. A cell-configuration system was built utilizing VO as the cathode and 1 M Mg(ClO) electrolyte within acetonitrile, together with Mg MoS ( x ≈ 2) as the anode to investigate the structural evolution and oxidation state and local structural changes of VO. The VO nanowires deliver an initial discharge/charge capacity of 103 mAh g/110 mAh g and the highest discharge capacity of 130 mAh g in the sixth cycle at C/20 rate in the cell-configuration system.