Printed High-Entropy Prussian Blue Analogs for Advanced Non-Volatile Memristive Devices.

Non-volatile memristors dynamically switch between high (HRS) and low resistance states (LRS) in response to electrical stimuli, essential for electronic memories, neuromorphic computing, and artificial intelligence. High-entropy Prussian blue analogs (HE-PBAs) are promising insertion-type battery materials due to their diverse composition, high structural integrity, and favorable ionic conductivity. This work proposes a non-volatile, bipolar memristor based on HE-PBA.

Overcoming Ion Trapping in Chevrel Phase Compounds via Tailored Anion Substitution: An Integrated Study of Theory, Synthesis, and In Operando Techniques for Reversible Aqueous Zn-Ion Batteries.

Sustainable batteries are key for powering electronic devices of the future, with aqueous zinc-ion batteries (AZIBs) standing out for their use of abundant, readily available elements, and safer production processes. Among the various electrode materials studied for AZIBs, the Chevrel Phase, MoS has shown promise due to its open framework, but issues with zinc ion trapping have limited its practical application. In this work, we employed computational methods to investigate the insertion-deinsertion mechanism in a series of isostructural MoSSe ( = 0-8) solid solutions as materials that could balance the gravimetric capacity and reversible cycling for AZIBs.

Nanosized Chevrel phases for dendrite-free zinc-ion based energy storage: unraveling the phase transformations.

The nanoscale form of the Chevrel phase, MoS, is demonstrated to be a highly efficient zinc-free anode in aqueous zinc ion hybrid supercapacitors (ZIHSCs). The unique morphological characteristics of the material when its dimensions approach the nanoscale result in fast zinc intercalation kinetics that surpass the ion transport rate reported for some of the most promising materials, such as TiS and TiSe. Raman spectroscopy, post-mortem X-ray diffraction, Hard X-ray photoelectron spectroscopy, and density functional theory (DFT) calculations were combined to understand the overall mechanism of the zinc ion (de)intercalation process.

Sodium Triflate Water-in-Salt Electrolytes in Advanced Battery Applications: A First-Principles-Based Molecular Dynamics Study.

Offering a compelling combination of safety and cost-effectiveness, water-in-salt (WiS) electrolytes have emerged as promising frontiers in energy storage technology. Still, there is a strong demand for research and development efforts to make these electrolytes ripe for commercialization. Here, we present a first-principles-based molecular dynamics (MD) study addressing in detail the properties of a sodium triflate WiS electrolyte for Na-ion batteries.

Simulation of oriented NMR spectra: Combining molecular dynamics and chemical shift tensor calculations.

Solid state NMR is widely used to study the orientation and other structural features of proteins and peptides in lipid bilayers. Using data obtained by PISEMA (Polarization Inversion Spin Exchange at Magic Angle) experiments, periodic spectral patterns arise from well-aligned α-helical molecules. Significant problems in the interpretation of PISEMA spectra may arise for systems that do not form perfectly defined secondary structures, like α-helices, or the signal pattern is disturbed by molecular motion.

Revealing the Structural Evolution of Electrode/Electrolyte Interphase Formation during Magnesium Plating and Stripping with operando EQCM-D.

Rechargeable magnesium batteries could provide future energy storage systems with high energy density. One remaining challenge is the development of electrolytes compatible with the negative Mg electrode, enabling uniform plating and stripping with high Coulombic efficiencies. Often improvements are hindered by a lack of fundamental understanding of processes occurring during cycling, as well as the existence and structure of a formed interphase layer at the electrode/electrolyte interface.

Molecular Modeling of Water-in-Salt Electrolytes: A Comprehensive Analysis of Polarization Effects and Force Field Parameters in Molecular Dynamics Simulations.

Accurate modeling of highly concentrated aqueous solutions, such as water-in-salt (WiS) electrolytes in battery applications, requires proper consideration of polarization contributions to atomic interactions. Within the force field molecular dynamics (MD) simulations, the atomic polarization can be accounted for at various levels. Nonpolarizable force fields implicitly account for polarization effects by incorporating them into their van der Waals interaction parameters.

All-Organic Battery Based on Deep Eutectic Solvent and Redox-Active Polymers.

Sustainable battery concepts are of great importance for the energy storage demands of the future. Organic batteries based on redox-active polymers are one class of promising storage systems to meet these demands, in particular when combined with environmentally friendly and safe electrolytes. Deep Eutectic Solvents (DESs) represent a class of electrolytes that can be produced from sustainable sources and exhibit in most cases no or only a small environmental impact.

Structures Controlled by Entropy: The Flexibility of Strychnine as Example.

To study the flexibility of strychnine, we performed molecular dynamics simulations with orientational tensorial constraints (MDOC). Tensorial constraints are derived from nuclear magnetic resonance (NMR) interaction tensors, for instance, from residual dipolar couplings (RDCs). Used as orientational constraints, they rotate the whole molecule and molecular parts with low rotational barriers.

Development of a Mg/O ReaxFF Potential to describe the Passivation Processes in Magnesium-Ion Batteries.

One of the key challenges preventing the breakthrough of magnesium-ion batteries (MIB) is the formation of a passivating boundary layer at the Mg anode. To describe the initial steps of Mg anode degradation by O impurities, a Mg/O ReaxFF (force field for reactive systems) parameter set was developed capable of accurately modeling the bulk, surface, adsorption, and diffusion properties of metallic Mg and the salt MgO. It is shown that O immediately dissociates upon first contact with the Mg anode (modeled as Mg(0001), Mg(10 0)A, and Mg(10 1)), heating the surface to several 1000 K.

Combining Deep Eutectic Solvents with TEMPO-based Polymer Electrodes: Influence of Molar Ratio on Electrode Performance.

For sustainable energy storage, all-organic batteries based on redox-active polymers promise to become an alternative to lithium ion batteries. Yet, polymers contribute to the goal of an all-organic cell as electrodes or as solid electrolytes. Here, we replace the electrolyte with a deep eutectic solvent (DES) composed of sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) and N-methylacetamide (NMA), while using poly(2,2,6,6-tetramethylpiperidin-1-yl-oxyl methacrylate) (PTMA) as cathode.

Single- to Few-Layer Nanoparticle Cathode Coating for Thiophosphate-Based All-Solid-State Batteries.

Bulk-type solid-state batteries (SSBs) composed of lithium thiophosphate superionic solid electrolytes (SEs) and high-capacity cathode active materials (CAMs) have recently attracted much attention for their potential application in next-generation electrochemical energy storage. However, compatibility issues between the key components in this kind of battery system are difficult to overcome. Here, we report on a protective cathode coating that strongly reduces the prevalence of detrimental side reactions between CAM and SE during battery operation.

Stability of Magnesium Binary and Ternary Compounds for Batteries Determined from First Principles.

Electrochemical stability is a critical performance parameter for the materials used as electrolytes and electrodes in batteries. Using first-principles electronic structure calculations, we have determined the electrochemical stability windows of magnesium binary and ternary spinel compounds. These materials are candidates for protective coatings, solid electrolytes, and cathodes in Mg batteries, which represent a promising sustainable alternative to Li-ion batteries that still dominate the battery market.

Influence of Chloride Ion Substitution on Lithium-Ion Conductivity and Electrochemical Stability in a Dual-Halogen Solid-State Electrolyte.

Li conducting halide solid-state electrolytes (SEs) are developing as an alternative to contemporary oxide and sulfide SEs for all-solid-state batteries (ASSBs) due to their high ionic conductivity, excellent chemical and electrochemical oxidation stability, and good deformability. However, the instability of halide SEs against the Li anode is still one of the key challenges that need to be addressed. Among halides, fluorides have shown a wider electrochemical stability window due to fluoride's high electronegativity and smaller ionic radius.

Descriptor and Scaling Relations for Ion Mobility in Crystalline Solids.

Ion mobility is a critical performance parameter not only in electrochemical energy storage and conversion but also in other electrochemical devices. On the basis of first-principles electronic structure calculations, we have derived a descriptor for the ion mobility in battery electrodes and solid electrolytes. This descriptor is entirely composed of observables that are easily accessible: ionic radii, oxidation states, and the Pauling electronegativities of the involved species.

Improved DFT Adsorption Energies with Semiempirical Dispersion Corrections.

Over the past years, density functional theory (DFT) became a widely approved and successful method for calculating properties of various materials and molecules. Especially suited for systems with delocalized electrons like metals, the efficient treatment of the van der Waals interaction remained a problem for DFT functionals within the generalized gradient approximation (GGA). Combining Grimme's D3 correction with the RPBE functional and using a previously published data set, we show that this yields a functional that is well-suited for an accurate and balanced description of adsorption energies.

First principles studies of self-diffusion processes on metallic lithium surfaces.

Due to the theoretical high specific capacity (3860 mAh/g) and the low standard electrode potential (-3.040 V vs. standard hydrogen electrode), rechargeable lithium metal batteries are considered as excellent energy storage systems.

Synthesis of Fast Fluoride-Ion-Conductive Fluorite-Type BaSb F (0.1 ≤ x ≤ 0.4): A Potential Solid Electrolyte for Fluoride-Ion Batteries.

Toward the development of high-performance solid electrolytes for fluoride-ion batteries, fluorite-type nanostructured solid solutions of BaSb F ( x ≤ 0.4) were synthesized by high-energy ball-milling method. Substitution of divalent Ba by trivalent Sb leads to an increase in interstitial fluoride-ion concentration, which enhances the ionic conductivity of the BaSb F (0.

Performance Improvement of V-Fe-Cr-Ti Solid State Hydrogen Storage Materials in Impure Hydrogen Gas.

Two approaches of engineering surface structures of V-Ti-based solid solution hydrogen storage alloys are presented, which enable improved tolerance toward gaseous oxygen (O) impurities in hydrogen (H) gas. Surface modification is achieved through engineering lanthanum (La)- or nickel (Ni)-rich surface layers with enhanced cyclic stability in an H/O mixture. The formation of a Ni-rich surface layer does not improve the cycling stability in H/O mixtures.

Change of the work function of platinum electrodes induced by halide adsorption.

The properties of a halogen-covered platinum(111) surface have been studied by using density functional theory (DFT), because halides are often present at electrochemical electrode/electrolyte interfaces. We focused in particular on the halogen-induced work function change as a function of the coverage of fluorine, chlorine, bromine and iodine. For electronegative adsorbates, an adsorption-induced increase of the work function is usually expected, yet we find a decrease of the work function for Cl, Br and I, which is most prominent at a coverage of approximately 0.