Batteries & Supercaps最新文献

Magnesium (Mg) is an abundant resource, and rechargeable Mg metal batteries (RMMBs) could help to achieve a sustainable society. However, practical Mg batteries require electrolyte materials compatible with both positive and negative Mg metal electrodes. Weakly coordinating anion (WCA)-based electrolytes meet these requirements and have had a groundbreaking impact on this field of research. In this study, the effects of multidentate oligoether additives on the structural characteristics of WCA-based electrolytes are examined. Integrating a linear oligoether of hexaglyme (G6) is found to be particularly effective at enhancing Mg plating/stripping performance, whereas the corresponding cyclic counterparts impart inferior performance. The combined electrochemical and spectroscopic analyses suggest that changes in the coordination environments of Mg²⁺ in solution with a specific amount of G6 are responsible for the enhanced interfacial charge-transfer kinetics. The results of this study will help guide the design of fully ethereal RMMB electrolytes compatible with highly reactive Mg metal-negative electrodes.

Zinc ion (Zn²⁺) energy storage devices are considered promising candidates for next-generation energy storage technologies, offering advantages in safety, low cost, and environmental friendliness. However, their commercialization remains limited by numerous challenges, including precise regulation of the molecular conformational relationships of electrolyte additives, optimization of electrode–electrolyte interfacial stability, scalability of manufacturing processes, and comprehensive analysis of long-term degradation mechanisms. Pure Zn anode interfaces face numerous unavoidable challenges, including dendrite growth, corrosion, passivation, and hydrogen evolution reactions. This review summarizes recent advances in electrolyte additives for Zn²⁺ energy storage devices, encompassing inorganic, organic, surfactant, and organic–inorganic composite additives, with a focus on the interaction mechanisms between additives, electrodes, and electrolytes. Furthermore, the optimal type and incorporation method of additives are discussed, emphasizing the positive impact of these factors on improving additive efficiency and performance. Finally, challenges and future directions for the development of electrolyte additives and advanced ZIHSs are proposed. This review aims to provide a comprehensive perspective to guide future research and development, advancing the efficiency, stability, and cost-effectiveness of aqueous Zn²⁺ energy storage devices.

Rechargeable Magnesium ion batteries (RMIBs) are considered one of the most promising energy storage devices due to their low cost, dendrite-free nature, and ecofriendliness. However, sluggish kinetics, irreversible structural changes, short cycle life, and low capacity of cathodes hinder their practical applications. Herein, Cobalt sulfide (CoS₂) nanosheets are synthesized using microwave method followed by chemical vapor deposition to serve as cathode material for RMIBs. CoS₂ nanosheets exhibit excellent electrochemical performance, providing a high specific capacity of 432 mAh g⁻¹ at 100 mA g⁻¹ current density. Moreover, CoS₂ also demonstrates a long-term operating stability over 2000 cycles giving 284 mAh g⁻¹ capacity at a current density of 500 mA g⁻¹ with approximately 96% capacity retention. Sustainable cathodic performance is the most desirous feature for commercialization. The density functional theory and experimental results reveal that the robust electrochemical performance of CoS₂ as a cathode is attributed to the high surface area of its sheet-like morphology. This work provides meaningful insights regarding morphological limitations and opportunities of CoS₂ cathode for applications in high-performance RMIBs.

The Front Cover shows the layout of the automated robotic battery materials research platform Aurora automating battery electrolyte formulation, battery cell assembly, and battery cell cycling into a stepwise, automated, application-relevant workflow. A large structured dataset with ontologized metadata detailing cell assembly and cycling protocols, alongside corresponding time series cycling data for almost 200 cells is provided as open research data. More information can be found in the Research Article by C. Battaglia and co-workers (DOI: 10.1002/batt.202500151).

The adsorption of alkali metal (AM) atoms on graphitic surfaces is one of the processes that determine the performance of carbon-based anode materials. In particular, when graphite derivatives such as hard carbon with increased surface area are considered, adsorption accounts for a significant amount of the AM storage capacity. While it is well known that the adsorption of Li and Na on pristine graphite is energetically unfavorable, this article shows how graphitic surfaces can be modified to tailor their adsorption properties. For this purpose, the adsorption of Li, Na, and K on graphitic model systems, containing defects and impurities as well as combinations thereof, is investigated by means of density functional theory. The results show that particular defects and impurity atoms can modify the adsorption strength of the surface such that Li and Na adsorption become energetically favorable, while at the same time, capacity loss via trapping of AM atoms is minimized.

Organic cathode-active materials with higher redox potential and specific capacity are significant in achieving higher energy density. However, the exploration of new active materials, including their design and synthesis, based on professional experience comes up against limitations. The work detailed in the Research Article by Y. Oaki and co-workers (DOI: 10.1002/batt.202500288) presents new performance prediction models for these materials, such as for their potential and capacity. The predictors enable the accelerated discovery of new high-performance organic cathode-active materials, such as those used in electric vehicles, drones, and high-altitude platform stations.

Supercapacitors are prized for their high-power delivery, though their energy storage capacity is generally lower than that of batteries. A novel one-pot strategy for synthesizing nitrogen-doped porous carbon derived from KOH and urea-activated wheat bread waste (Triticum aestivum) is presented. This unique synthesis simultaneously achieves chemical activation and nitrogen doping in a single-step process, offering a cost-effective and scalable route for high-performance electrode materials. The supercapacitive properties of bread waste-derived activated carbon (BWC-700) in a 1 M H₂SO₄ aqueous electrolyte are investigated, with 0.01 M hydroquinone (HQ) acting as a redox-active agent. Morphological analysis via field-emission scanning electron microscopy confirms the material's hierarchical porous structure. The (BWC-700) exhibits a specific capacitance of 486 F g⁻¹ at a current density of 1 A g⁻¹ in a half-cell configuration, with specific capacities of 1422 C g⁻¹ and 904 C g⁻¹ in three- and two-electrode systems, respectively. When HQ is incorporated into the electrolyte, the AC demonstrates excellent cyclic stability, retaining 82% of its capacitance after 5000 cycles. Notably, BWC-700 achieves a peak energy density of 56.5 Wh kg⁻¹, outperforming symmetric supercapacitors. These findings underscore the novel combination of waste valorization, green synthesis, and redox-enhanced energy storage, making this work highly relevant and competitive in the rapidly evolving field of supercapacitors.

The effect of an anion from the electrolyte salt plays a crucial role in modulating the solvation structure of the cation and the electrochemical performances of the energy storage systems. Herein, the effect of different anions such as chlorides (Cl⁻), nitrates (NO₃⁻), sulfates (SO₄²⁻), and their influence on the solvation structure, diffusivity of Zn²⁺ cation, redox kinetics, and ion storing behavior of Zn-based Prussian blue analogue (PBA) electrodes are explored. Combining molecular dynamics simulations and experimental observations, the results divulge that different anions can significantly modulate the solvation shell and diffusivity of the cation, thereby influencing the electrochemical properties of the PBA electrodes. Further, increased anion concentration and its consequences on the aforementioned properties are investigated by employing 6 m water-in-salt electrolyte (WiSE). It is found that in ZnCl₂, a moderate Zn²⁺-Cl⁻ interaction offers higher ion diffusivity, thereby facilitating more efficient Zn²⁺ intercalation into the PBA electrode, resulting highest specific capacity of 56 mAh g⁻¹ at 2C-rate and the highest coulombic efficiency of 80% in 1 m ZnCl₂ and shows superior cycling stability in long-term cycling in 6 m-WiSE comparison to other anions. This work highlights the pivotal role of anions in tuning electrolyte molecular structure and its dynamics, ultimately governing cation transport and electrode kinetics in aqueous zinc-ion batteries.

One of the challenges in the development of Mg batteries is the lack of Mg electrolytes with good compatibility with both the Mg metal anode and cathode materials. In recent years, Mg salts based on weakly coordinating anions have emerged as promising Mg electrolytes. In this work, we systematically investigate the effects of salt concentration on the physicochemical properties, salt–solvent interactions, and electrochemical performance of the Mg[Al(hfip)₄]₂/G2 electrolyte. Infrared (IR) and Raman spectroscopy are used to study the changes in the electrolyte speciation across different concentrations, indicating a decreased amount of free glyme solvent with higher salt concentration. Mg plating/stripping of selected electrolytes is evaluated through three different testing protocols (conventional cycling, macrocycling, and cycling with added open-circuit voltage (OCV) rests) and compatibility with different cathode materials such as Chevrel phase, sulfur, and various organic redox-active compounds. In the electrochemical tests, more concentrated electrolytes demonstrated improved cathode cycling efficiency and more stable Mg plating/stripping, making an argument for Mg electrolytes with higher salt concentration. However, higher salt concentrations can increase the cost of Mg electrolytes. Further Mg electrolyte optimization should focus on adjusting electrolyte composition to specific electrode materials and other cell components, while maintaining a reasonable cost.

The rising costs of cobalt and nickel, alongside mounting environmental concerns, have spurred intensive research into alternative battery chemistries that eliminate these critical elements. This shift aligns with the broader industry push toward low-cost, sustainable materials that can rival the performance of lithiumironphosphate (LFP) systems. In this context, the present work introduces a layered oxide cathode composition, NaFe_0.45Mn_0.5Ti_0.05O₂ (NFMTO), which delivers high specific capacity and enhanced cycling stability. The substitution of Ti⁴⁺ into the Fe/Mn lattice effectively modifies the transition metal–oxygen (TM-O) layer spacing, thereby improving structural stability during cycling. As a result, the NFMTO cathode exhibits an initial discharge capacity of 125 mAh g⁻¹ at 0.1C (2.0–4.2 V vs. Na⁺/Na) and retains 78.4% of its capacity after 50 cycles. Additionally, it delivers 118 mAh g⁻¹ with 70% capacity retention over 200 cycles in a voltage window of 2.0–4.0 V. The full-cell performance of NFMTO is evaluated in a pouch cell configuration using hard carbon as the anode, further demonstrating its practical viability. The assembled pouch cell delivered an initial discharge capacity of 103 mAh g⁻¹ at 0.05C (2.0–4.2 V) and retained 90% of its capacity after 10 cycles.