Challenges and prospects of the role of solid electrolytes in the revitalization of lithium metal batteries

The scientific community is continuously committed to the search for new high energy electrochemical storage devices. In this regard, lithium metal batteries, due to their very high electrochemical energy storage capacity, appear to be a highly appealing choice. Unfortunately, the use of lithium metal as the anode may lead to some safety hazards due to its uneven deposition upon charging, resulting in dendrite growth and eventual shorting of the battery. This issue may be successfully addressed by using intrinsically safer electrolytes capable of establishing a physical barrier at the electrode interface. The most promising candidates are solid electrolytes, either polymeric or inorganic. The main purpose of this review is to describe the present status of worldwide research on these electrolyte materials together with a critical discussion of their transport properties and compatibility with metallic lithium, hoping to provide some general guidelines for the development of innovative and safe lithium metal batterie

Consistent quantum mechanics admits no mereotopology

It is standardly assumed in discussions of quantum theory that physical systems can be regarded as having well-defined Hilbert spaces. It is shown here that a Hilbert space can be consistently partitioned only if its components are assumed not to interact. The assumption that physical systems have well-defined Hilbert spaces is, therefore, physically unwarranted.Comment: 10 pages; to appear in Axiomathe

Metal–organic framework derived Fe7S8 nanoparticles embedded in heteroatom-doped carbon with Lithium and Sodium storage capability

Iron sulfides are promising materials for lithium- and sodium-ion batteries owing to their high theoretical capacity and widespread abundance. Herein, the performance of an iron sulfide-carbon composite, synthesized from a Fe-based metal–organic framework (Fe-MIL-88NH2) is reported. The material is composed of ultrafine Fe7S8 nanoparticles (<10 nm in diameter) embedded in a heteroatom (N, S, and O)-doped carbonaceous framework (Fe7S8@HD-C), and is obtained via a simple and efficient one-step sulfidation process. The Fe7S8@HD-C composite, investigated in diethylene glycol dimethyl ether-based electrolytes as anode material for lithium and sodium batteries, shows high reversible capacities (930 mAh g−1 for lithium and 675 mAh g−1 for sodium at 0.1 A g−1). In situ X-ray diffraction reveals an insertion reaction to occur in the first lithiation and sodiation steps, followed by conversion reactions. The composite electrodes show rather promising long-term cycling stability and rate capability for sodium storage in glyme electrolyte, while an improved rate capacity and long-term cycling stability (800 mAh g−1 after 300 cycles at 1 A g−1) for lithium can be achieved using conventional carbonates

Zinc‐Ion Hybrid Supercapacitors Employing Acetate‐Based Water‐in‐Salt Electrolytes

Halide-free, water-in-salt electrolytes (WiSEs) composed of potassium acetate (KAc) and zinc acetate (ZnAc$_2$) are investigated as electrolytes in zinc-ion hybrid supercapacitors (ZHSs). Molecular dynamics simulations demonstrate that water molecules are mostly non-interacting with each other in the highly concentrated WiSEs, while “bulk-like water” regions are present in the dilute electrolyte. Among the various concentrated electrolytes investigated, the 30 m KAc and 1 m ZnAc$_2$ electrolyte (30K1Zn) grants the best performance in terms of reversibility and stability of Zn plating/stripping while the less concentrated electrolyte cannot suppress corrosion of Zn and hydrogen evolution. The ZHSs utilizing 30K1Zn, in combination with a commercial activated carbon (AC) positive electrode and Zn as the negative electrode, deliver a capacity of 65 mAh g$^{−1}$ (based on the AC weight) at a current density of 5 A g$^{−1}$. They also offer an excellent capacity retention over 10 000 cycles and an impressive coulombic efficiency (≈100%)

Embedding Heterostructured α‐MnS/MnO Nanoparticles in S‐Doped Carbonaceous Porous Framework as High‐Performance Anode for Lithium‐Ion Batteries

In this work, the synthesis of α-MnS/MnO/S-doped C micro-rod composites via a simple sulfidation process is demonstrated, starting from a Mn-based metal-organic framework. The resulting heterostructured α-MnS/MnO nanoparticles (8±2 nm) are uniformly embedded into the S-doped carbonaceous porous framework with hierarchical micro-/meso-porosity. The combination of structural and compositional characteristics results in the promising electrochemical performance of the as-obtained composites as anode materials for lithium-ion batteries, coupled with high reversible capacity (940 mAh $g^{−1}$ at 0.1 A $g^{−1}$), excellent rate capability as well as long cycling lifespan at high rate of 2.0 A $g^{−1}$ for 2000 cycles with the eventual capacity of ∼300 mAh $g^{−1}$. Importantly, in situ X-ray diffraction studies clearly reveal mechanistic details of the lithium storage mechanism, involving multistep conversion processes upon initial lithiation

Reversible Copper Sulfide Conversion in Nonflammable Trimethyl Phosphate Electrolytes for Safe Sodium‐Ion Batteries

Rechargeable sodium-ion batteries are considered promising candidates for low-cost and large-scale energy storage systems. However, the limited energy density, cyclability, and safety issues remain challenges for practical applications. Herein, investigation of the Cu1.8S/C composite material as the negative electrode active (conversion) material in combination with a concentrated electrolyte composed of a 3.3 m solution of sodium bis(fluorosulfonyl)imide (NaFSI) in trymethyl phosphate and fluoroethylene carbonate (FEC) as the additive is reported on. Such a combination enables the stable cycling of the conversion-type Cu1.8S/C electrode material for hundreds of cycles with high capacity (380 mAh g−1). Both the salt (NaFSI) and the additive (FEC) contribute to the formation of a stable NaF-rich solid electrolyte interphase (SEI) on the anode surface. A full cell using the Na3V2(PO4)3/C cathode also demonstrates stable cycling performance for 200 cycles with a promising Coulombic efficiency (CE) (99.3%). These findings open new opportunities for the development of safer rechargeable sodium-ion batteries

Unveiling the Intricate Intercalation Mechanism in Manganese Sesquioxide as Positive Electrode in Aqueous Zn‐Metal Battery

In the family of Zn/manganese oxide batteries with mild aqueous electrolytes, cubic α-Mn$_{2}$O$_{3}$ with bixbyite structure is rarely considered, because of the lack of the tunnel and/or layered structure that are usually believed to be indispensable for the incorporation of Zn ions. In this work, the charge storage mechanism of α-Mn$_{2}$O$_{3}$ is systematically and comprehensively investigated. It is demonstrated that the electrochemically induced irreversible phase transition from α-Mn$_{2}$O$_{3}$ to layered-typed L-Zn$_{x}$MnO$_{2}$, coupled with the dissolution of Mn$^{2+}$ and OH$^{-}$ into the electrolyte, allows for the subsequent reversible de-/intercalation of Zn$^{2+}$. Moreover, it is proven that α-Mn$_{2}$O$_{3}$ is not a host for H$^{+}$. Instead, the MnO$_{2}$ formed from L-Zn$_{x}$MnO$_{2}$ and the Mn^{2+ in the electrolyte upon the initial charge is the host for H$^{+}$. Based on this electrode mechanism, combined with fabricating hierarchically structured mesoporous α-Mn$_{2}$O$_{3}$ microrod array material, an unprecedented rate capability with 103 mAh g−1 at 5.0 A g−1 as well as an appealing stability of 2000 cycles (at 2.0 A g$^{-1}$) with a capacity decay of only ≈0.009% per-cycle are obtained

Drawing Boundaries

In “On Drawing Lines on a Map” (1995), I suggested that the different ways we have of drawing lines on maps open up a new perspective on ontology, resting on a distinction between two sorts of boundaries: fiat and bona fide. “Fiat” means, roughly: human-demarcation-induced. “Bona fide” means, again roughly: a boundary constituted by some real physical discontinuity. I presented a general typology of boundaries based on this opposition and showed how it generates a corresponding typology of the different sorts of objects which boundaries determine or demarcate. In this paper, I describe how the theory of fiat boundaries has evolved since 1995, how it has been applied in areas such as property law and political geography, and how it is being used in contemporary work in formal and applied ontology, especially within the framework of Basic Formal Ontology

Current status and future perspectives of lithium metal batteries

With the lithium-ion technology approaching its intrinsic limit with graphite-based anodes, Li metal is recently receiving renewed interest from the battery community as potential high capacity anode for next-generation rechargeable batteries. In this focus paper, we review the main advances in this field since the first attempts in the mid-1970s. Strategies for enabling reversible cycling and avoiding dendrite growth are thoroughly discussed, including specific applications in all-solid-state (inorganic and polymeric), Lithium–Sulfur (Li–S) and Lithium-O2 (air) batteries. A particular attention is paid to recent developments of these battery technologies and their current state with respect to the 2030 targets of the EU Integrated Strategic Energy Technology Plan (SET-Plan) Action 7