Batteries & Supercaps最新文献

Manufacturing aqueous batteries based on the magnesium cations is an important step towards more sustainable and safer energy storage solutions. Thus, it is important to understand how these systems age and which species are formed throughout numerous charge/discharge cycles. To this end, we have used radiolysis to induce accelerated ageing in concentrated aqueous solutions of magnesium bistriflimide Mg(TFSI)₂ (also called “water-in-salt electrolytes” or WISEs). We demonstrate in this work that the degradation products formed, whether in the gas or liquid phase, are very similar to those formed in concentrated LiTFSI aqueous solutions. In fact, the behavior under ionizing radiation is driven by the anion/water molar ratio regardless of whether the cation is Li⁺ or Mg²⁺. This is because both cations are non-reactive, and the bond strengths in the TFSI⁻ anion do not vary with the nature of the cation. Reaction mechanisms are proposed to explain the formation of several species under ionizing radiation.

Among emerging rechargeable batteries, rechargeable aluminum-ion batteries (AIBs) stand out for their high specific capacities and the abundance of aluminum, positioning them as an attractive electrochemical energy storage option. Despite the superior electrochemical performance of non-aqueous AIBs, aqueous aluminum-ion batteries (AAIBs) have garnered extensive research interest for their low cost and enhanced safety. Yet, realizing high energy density in AAIBs poses significant challenges. This article systematically reviews strategies and recent advancements in cathodes, anodes, and electrolytes aimed at achieving high energy density in AAIBs. It concludes with a forward-looking perspective on the design of AAIBs with high energy density and prolonged cycle life, highlighting promising directions for future researches.

The successful utilization of innovative sulfide-based solid-state batteries in energy storage hinges on developing scalable technologies and machinery for upscaling their production. While multiple Gigafactories for lithium-ion batteries are already operational worldwide, the upscaling of solid-state batteries exhibiting their full potential remains to be seen in the near future. In this study, the conventional production of lithium-ion batteries is reconsidered, and the feasibility of seamlessly integrating sulfide-based solid-state batteries into the existing process chains is discussed. Scalable technologies and key challenges along the process chain of sulfide-based solid-state batteries are accordingly addressed. Experimental investigations yield crucial insights into enabling large-scale production of sulfide-based battery components while highlighting remaining challenges from a production perspective. An overview of the roll-to-roll machinery housed in microenvironments under an inert atmosphere in the “Sulfidic Cell Production Advancement Center” at the Institute for Machine Tools and Industrial Management at the Technical University of Munich is given.

Sodium-oxygen batteries are emerging as new battery systems. Deep understanding of the origin of overpotential and the kinetic process in sodium-oxygen batteries remain challenging yet critical. We apply a method of distribution of relaxation time (DRT) to decipher the electrochemical impedance spectroscopy (EIS), allowing us to monitor the changes of different kinetic processes during the discharging and charging. The origin of the overpotential in a battery was further comprehensively investigated combining DRT analysis with differential electrochemical mass spectrometry, Raman and other characterizations. Overpotential is found to primarily stem from oxygen mass transport during discharging, and from poor solid-solid contact at the electrode surface during charging. Our work demonstrates the study of kinetic processes using DRT analysis, and suggests effective ways to improve the performances of sodium-oxygen batteries.

Molybdenum disulfide (MoS₂)-based cathodes have exhibited good electrochemical reactions in all phenyl complex (APC) electrolytes. However, APC electrolytes are highly corrosive and susceptible to oxidation. Alternatively, magnesium fluorinated alkoxyaluminate electrolyte (Mg[Al(HFIP)₄]₂) is a pioneering chloride-free electrolyte with remarkable electrochemical activity in rechargeable Mg batteries (RMBs). This study aims to investigate the compatibility of various MoS₂ nanomaterials with Mg[Al(HFIP)₄]₂ in RMBs. Seven MoS₂ nanomaterials were synthesized under different hydro/solvothermal conditions and evaluated as cathode materials in RMBs. The results revealed that the electrochemical activity of the as-synthesized MoS₂ in RMBs significantly varied and MoS₂ with high content of 1T-phase (M5) exhibited the best specific capacity of ca. 35 mAh g⁻¹. Heteroatom doping, graphene oxide (GO) incorporation, and dual-salt electrolytes were employed to enhance the electrochemical performance of M5. The electrochemical tests showed that all doped-MoS₂ and GO-MoS₂ delivered poor specific capacities (<20 mAh g⁻¹), properly due to the disorder of the cathode material and the entrapment of Mg²⁺ ions. In contrast, dual-salt electrolytes (0.3 M Mg[Al(HFIP)₄]₂/0.3 M LiCl) improved the initial specific capacity by 242 %. This is attributed to the preferential intercalation of Li⁺ ions that reduces the diffusion energy barrier and facilitates the intercalation of Mg⁺² ions.

The utilization of tetraethylammonium perfluorobutane sulfonate as a promising alternative salt for electrolyte solutions in electrochemical double layer capacitors is introduced in this study. A thorough analysis of the physical and electrochemical characteristics of tetraethylammonium perfluorobutane sulfonate was conducted, including the assessment of its ionic conductivity, viscosity, and thermal behavior, using a 1 M solution in acetonitrile. Comparative assessments were made between the performance of this novel electrolyte and two well-studied electrolytes: 1 M tetraethylammonium tetrafluoroborate and 1 M tetraethylammonium bis(trifluoromethanesulfonyl)imide in acetonitrile, focusing on electrochemical performance and long-term stability. Furthermore, an investigation into the impact of tetraethylammonium perfluorobutane sulfonate on the anodic dissolution of aluminum current collectors was conducted. The results highlight the potential of tetraethylammonium perfluorobutane sulfonate as an effective replacement for bis(trifluoromethanesulfonyl)imide-based electrolytes.

To improve the sulfur reaction kinetics and inhibit the notorious shuttle effects, a tube-in-tube structure decorated by carbon nanotubes (CNT) and Fe₃C nanoparticles (TIT/Fe₃C-CNT) is designed as sulfur host for lithium-sulfur batteries (LSBs) in this work. The construction of tube-in-tube structure increases the active sites and the specific surface area of the material. Additionally, Fe₃C nanoparticles can effectively adsorb the soluble lithium polysulfides and promote their catalytic conversion, thus greatly alleviating the shuttle effects. As a result of these advantages, the TIT/Fe₃C-CNT-based cathode exhibits a high reversible capacity of 841 mAh g⁻¹ after 200 cycles with a low decay of 0.056 % per cycle at 0.5 C. This work provides a promising and reasonable approach to the rational design of sulfur host for LSBs.

Benefiting from the natural attributes of exceptional chemical stability, versatility, porous structure, and tunable pore sizes, pristine metal-organic frameworks, MOFs, have gained widespread recognition as advanced anodes and cathodes for potassium-ion batteries, PIBs, showcasing several promising features in electrochemical energy storage devices. Here, a comprehensive review highlights recent advancements in pristine MOF-based electrodes for PIBs, focusing on the detailed characteristics, redox reaction monachism, and effective strategies to improve electrochemical energy performance, which provides guidance for further developments in electrode design and optimization strategies aimed at achieving prolonged cyclability and capacity retention.

Lithium-ion insertion/deinsertion in anode at slow rates limits the power performance of energy storage devices. Here, a new pseudocapacitive electrode with high reversible capacity during cycling has been proposed for a lithium-ion capacitor. The lithium-fluoride garnet, namely Na₃Fe₂Li₃F₁₂, is obtained via precipitation from an aqueous solution at room temperature using abundant materials and exhibits a high discharge capacity of 746 mAh g⁻¹. After the first charging cycle, the energy is stored via fast pseudocapacitive faradaic reactions which are facilitated by the nanocrystalline transport pathways with no structural modification to the electrode. The high stability window of F-garnet allows extracting cell voltages of 2.2–3.2 V in a lithium-ion capacitor where it is coupled with a porous carbon-based positive electrode, with a high energy efficiency of 93 % maintained for 10000 charge/discharge cycles. This study opens a new research direction concerning pseudocapacitive anode materials for enhancing power performance and even replacing the traditional battery-like anode materials.

A range of techniques for the coating of high purity alumina (HPA) on porous polypropylene battery separators has been investigated. A slurry was prepared by dispersion of the alumina powder in acetone solvent and poly (vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) as the binder to obtain an excellent adhesion to the membrane. Doctor blade, spin coating, and electro-spin coating techniques were utilized to coat a thin layer of HPA on the separator that was followed up with a calendering step to improve compactness, decrease thickness and enhance adhesion. Furthermore, the effect of HPA particle size, distribution, and the use of a calendering step on coating thickness, compactness, and electrochemical performance were investigated using three HPA sources. The doctor blade technique was found to give the most uniform coating with the best mechanical properties and high-temperature resistance. The coated separators were incorporated into lithium-ion coin cells to evaluate the rate capability and long-term cycling performance.