A self-healing plastic ceramic electrolyte by an aprotic dynamic polymer network for lithium metal batteries.

Oxide ceramic electrolytes (OCEs) have great potential for solid-state lithium metal (Li) battery applications because, in theory, their high elastic modulus provides better resistance to Li dendrite growth. However, in practice, OCEs can hardly survive critical current densities higher than 1 mA/cm. Key issues that contribute to the breakdown of OCEs include Li penetration promoted by grain boundaries (GBs), uncontrolled side reactions at electrode-OCE interfaces, and, equally importantly, defects evolution (e.

Fundamental mechanistic insights into the catalytic reactions of Li─S redox by Co single-atom electrocatalysts via operando methods.

Lithium-sulfur batteries represent an attractive option for energy storage applications. A deeper understanding of the multistep lithium-sulfur reactions and the electrocatalytic mechanisms are required to develop advanced, high-performance batteries. We have systematically investigated the lithium-sulfur redox processes catalyzed by a cobalt single-atom electrocatalyst (Co-SAs/NC) via operando confocal Raman microscopy and x-ray absorption spectroscopy (XAS).

Simulated sulfur K-edge X-ray absorption spectroscopy database of lithium thiophosphate solid electrolytes.

X-ray absorption spectroscopy (XAS) is a premier technique for materials characterization, providing key information about the local chemical environment of the absorber atom. In this work, we develop a database of sulfur K-edge XAS spectra of crystalline and amorphous lithium thiophosphate materials based on the atomic structures reported in Chem. Mater.

Boosting the interfacial superionic conduction of halide solid electrolytes for all-solid-state batteries.

Designing highly conductive and (electro)chemical stable inorganic solid electrolytes using cost-effective materials is crucial for developing all-solid-state batteries. Here, we report halide nanocomposite solid electrolytes (HNSEs) ZrO(-ACl)-AZrCl (A = Li or Na) that demonstrate improved ionic conductivities at 30 °C, from 0.40 to 1.

Identification and Catalysis of the Potential-Limiting Step in Lithium-Sulfur Batteries.

The Li-S chemistry is thermodynamically promising for high-density energy storage but kinetically challenging. Over the past few years, many catalyst materials have been developed to improve the performance of Li-S batteries and their catalytic role has been increasingly accepted. However, the classic catalytic behavior, i.

Understanding Electrochemical Reaction Mechanisms of Sulfur in All-Solid-State Batteries through Operando and Theoretical Studies.

Due to its outstanding safety and high energy density, all-solid-state lithium-sulfur batteries (ASLSBs) are considered as a potential future energy storage technology. The electrochemical reaction pathway in ASLSBs with inorganic solid-state electrolytes is different from Li-S batteries with liquid electrolytes, but the mechanism remains unclear. By combining operando Raman spectroscopy and ex situ X-ray absorption spectroscopy, we investigated the reaction mechanism of sulfur (S ) in ASLSBs.

Carbon-free high-performance cathode for solid-state Li-O battery.

The development of a cathode for solid-state lithium-oxygen batteries has been hindered in practice by a low capacity and limited cycle life despite their potential for high energy density. Here, a previously unexplored strategy is proposed wherein the cathode delivers a specific capacity of 200 milliampere hour per gram over 665 discharge/charge cycles, while existing cathodes achieve only ~50 milliampere hour per gram and ~100 cycles. A highly conductive ruthenium-based composite is designed as a carbon-free cathode by first-principles calculations to avoid the degradation associated with carbonaceous materials, implying an improvement in stability during the electrochemical cycling.

Investigation of Ca Insertion into α-MoO Nanoparticles for High Capacity Ca-Ion Cathodes.

Calcium-ion batteries (CIBs) are a promising alternative to lithium-ion batteries (LIBs) due to the low redox potential of calcium metal and high abundance of calcium compounds. Due to its layered structure, α-MoO is regarded as a promising cathode host lattice. While studies have reported that α-MoO can reversibly intercalate Ca ions, limited electrochemical activity has been noted, and its reaction mechanism remains unclear.

Understanding the Roles of the Electrode/Electrolyte Interface for Enabling Stable Li∥Sulfurized Polyacrylonitrile Batteries.

Sulfurized polyacrylonitrile (SPAN) is a promising high-capacity cathode material. In this work, we use spatially resolved X-ray absorption spectroscopy combined with X-ray fluorescence (XRF) microscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy to examine the structural transformation of SPAN and the critical role of a robust cathode-electrolyte interface (CEI) on the electrode. LiS species forms during the cycling of SPAN.

Hierarchical nickel valence gradient stabilizes high-nickel content layered cathode materials.

High-nickel content cathode materials offer high energy density. However, the structural and surface instability may cause poor capacity retention and thermal stability of them. To circumvent this problem, nickel concentration-gradient materials have been developed to enhance high-nickel content cathode materials' thermal and cycling stability.

Identification of LiH and nanocrystalline LiF in the solid-electrolyte interphase of lithium metal anodes.

A comprehensive understanding of the solid-electrolyte interphase (SEI) composition is crucial to developing high-energy batteries based on lithium metal anodes. A particularly contentious issue concerns the presence of LiH in the SEI. Here we report on the use of synchrotron-based X-ray diffraction and pair distribution function analysis to identify and differentiate two elusive components, LiH and LiF, in the SEI of lithium metal anodes.

Understanding the Mechanism of High Capacitance in Nickel Hexaaminobenzene-Based Conductive Metal-Organic Frameworks in Aqueous Electrolytes.

Recently, intrinsically conductive metal-organic frameworks (MOFs) have demonstrated promising performance in fast-charging energy storage applications and may outperform some current electrode materials (, porous carbons) for supercapacitors in terms of both gravimetric and volumetric capacitance. In this report, we examine the mechanism of high capacitance in a nickel hexaaminobenzene-based MOF (NiHAB). Using a combination of Raman and X-ray absorption spectroscopies, as well as detailed electrochemical studies in a series of aqueous electrolytes, we demonstrate that the charge storage mechanism is, in fact, a pH-dependent surface pseudocapacitance, and unlike typical inorganic systems, where transition metals change oxidation state during charge/discharge cycles, NiHAB redox activity is ligand-centered.

Structural Stabilization of P2-type Sodium Iron Manganese Oxides by Electrochemically Inactive Mg Substitution: Insights of Redox Behavior and Voltage Decay.

Layered P2-type Na Mn Fe O cathode material is a promising candidate for next-generation sodium-ion batteries due to the economical and environmentally benign characteristics of Mn and Fe. The poor cycling stability of the material, however, is still a problem that must be solved. To address the problem, electrochemically inactive Mg was introduced into the structure by substituting some of the Fe ions.

Revealing Reaction Pathways of Collective Substituted Iron Fluoride Electrode for Lithium Ion Batteries.

Metal fluorides present a high redox potential among the conversion-type compounds, which make them specially work as cathode materials of lithium ion batteries. To mitigate the notorious cycling instability of conversion-type materials, substitutions of anion and cation have been proposed but the role of foreign elements in reaction pathway is not fully assessed. In this work, we explored the lithiation pathway of a rutile-FeCoOF cathode with multimodal analysis, including and transmission electron microscopy and synchrotron X-ray techniques.

Salivary microbiota in periodontal health and disease and their changes following nonsurgical periodontal treatment.

Purpose: The aims of this study were to examine the salivary microbiota in conditions of periodontal health and disease and to explore microbial changes following nonsurgical periodontal treatment.

Methods: Non-stimulated saliva samples were collected from 4 periodontally healthy participants at baseline and from 8 patients with chronic periodontitis at baseline and 3 months following nonsurgical periodontal therapy. The V3 and V4 regions of the 16S rRNA gene from the DNA of saliva samples were amplified and sequenced.

Tailoring Solution-Processable Li Argyrodites LiPMSI (M = Ge, Sn) and Their Microstructural Evolution Revealed by Cryo-TEM for All-Solid-State Batteries.

Owing to their high Li conductivities, mechanical sinterability, and solution processability, sulfide Li argyrodites have attracted much attention as enablers in the development of high-performance all-solid-state batteries with practicability. However, solution-processable Li argyrodites have been developed only for a composition of LiPSX (X = Cl, Br, I) with insufficiently high Li conductivities (∼10 S cm). Herein, we report the highest Li conductivity of 0.

Anionic redox reaction in layered NaCrTiS through electron holes formation and dimerization of S-S.

The use of anion redox reactions is gaining interest for increasing rechargeable capacities in alkaline ion batteries. Although anion redox coupling of S and (S) through dimerization of S-S in sulfides have been studied and reported, an anion redox process through electron hole formation has not been investigated to the best of our knowledge. Here, we report an O3-NaCrTiS cathode that delivers a high reversible capacity of ~186 mAh g (0.

Improving the Electrochemical Performance and Structural Stability of the LiNiCoAlO Cathode Material at High-Voltage Charging through Ti Substitution.

LiNiCoAlO (NCA) has been proven to be a good cathode material for lithium-ion batteries (LIBs), especially in electric vehicle applications. However, further elevating energy density of NCA is very challenging. Increasing the charging voltage of NCA is an effective method, but its structural instability remains a problem.

Anomalous metal segregation in lithium-rich material provides design rules for stable cathode in lithium-ion battery.

Despite the importance of studying the instability of delithiated cathode materials, it remains difficult to underpin the degradation mechanism of lithium-rich cathode materials due to the complication of combined chemical and structural evolutions. Herein, we use state-of-the-art electron microscopy tools, in conjunction with synchrotron X-ray techniques and first-principle calculations to study a 4d-element-containing compound, LiRuMnO. We find surprisingly, after cycling, ruthenium segregates out as metallic nanoclusters on the reconstructed surface.

Atomically Dispersed Molybdenum Catalysts for Efficient Ambient Nitrogen Fixation.

NH synthesis by the electrocatalytic N reduction reaction (NRR) under ambient conditions is an appealing alternative to the currently employed industrial method-the Haber-Bosch process-that requires high temperature and pressure. We report single Mo atoms anchored to nitrogen-doped porous carbon as a cost-effective catalyst for the NRR. Benefiting from the optimally high density of active sites and hierarchically porous carbon frameworks, this catalyst achieves a high NH yield rate (34.

High energy-density and reversibility of iron fluoride cathode enabled via an intercalation-extrusion reaction.

Iron fluoride, an intercalation-conversion cathode for lithium ion batteries, promises a high theoretical energy density of 1922 Wh kg However, poor electrochemical reversibility due to repeated breaking/reformation of metal fluoride bonds poses a grand challenge for its practical application. Here we report that both a high reversibility over 1000 cycles and a high capacity of 420 mAh g can be realized by concerted doping of cobalt and oxygen into iron fluoride. In the doped nanorods, an energy density of ~1000 Wh kg with a decay rate of 0.

Introducing Fe into Nickel-Iron Layered Double Hydroxide: Local Structure Modulated Water Oxidation Activity.

Exploring materials with regulated local structures and understanding how the atomic motifs govern the reactivity and durability of catalysts are a critical challenge for designing advanced catalysts. Herein we report the tuning of the local atomic structure of nickel-iron layered double hydroxides (NiFe-LDHs) by partially substituting Ni with Fe to introduce Fe-O-Fe moieties. These Fe -containing NiFe-LDHs exhibit enhanced oxygen evolution reaction (OER) activity with an ultralow overpotential of 195 mV at the current density of 10 mA cm , which is among the best OER catalytic performance to date.

Utilizing Co/Co Redox Couple in P2-Layered NaCoMnTiO Cathode for Sodium-Ion Batteries.

Developing sodium-ion batteries for large-scale energy storage applications is facing big challenges of the lack of high-performance cathode materials. Here, a series of new cathode materials NaCo Mn TiO for sodium-ion batteries are designed and synthesized aiming to reduce transition metal-ion ordering, charge ordering, as well as Na and vacancy ordering. An interesting structure change of NaCo Mn TiO from orthorhombic to hexagonal is revealed when Co content increases from = 0 to 0.

Explore the Effects of Microstructural Defects on Voltage Fade of Li- and Mn-Rich Cathodes.

Li- and Mn-rich (LMR) cathode materials have been considered as promising candidates for energy storage applications due to high energy density. However, these materials suffer from a serious problem of voltage fade. Oxygen loss and the layered-to-spinel phase transition are two major contributors of such voltage fade.

Quantification of Honeycomb Number-Type Stacking Faults: Application to Na3Ni2BiO6 Cathodes for Na-Ion Batteries.

Ordered and disordered samples of honeycomb-lattice Na3Ni2BiO6 were investigated as cathodes for Na-ion batteries, and it was determined that the ordered sample exhibits better electrochemical performance, with a specific capacity of 104 mA h/g delivered at plateaus of 3.5 and 3.2 V (vs Na(+)/Na) with minimal capacity fade during extended cycling.