Electrochemical Activation of LiGaO: Implications for Ga-Doped Garnet Solid Electrolytes in Li-Metal Batteries.

Ga-doped LiLaZrO garnet solid electrolytes exhibit the highest Li-ion conductivities among the oxide-type garnet-structured solid electrolytes, but instabilities toward Li metal hamper their practical application. The instabilities have been assigned to direct chemical reactions between LiGaO coexisting phases and Li metal by several groups previously. Yet, the understanding of the role of LiGaO in the electrochemical cell and its electrochemical properties is still lacking.

Chemical Prelithiated 3D Lithiophilic/-Phobic Interlayer Enables Long-Term Li Plating/Stripping.

The up-to-date lifespan of zero-excess lithium (Li) metal batteries is limited to a few dozen cycles due to irreversible Li-ion loss caused by interfacial reactions during cycling. Herein, a chemical prelithiated composite interlayer, made of lithiophilic silver (Ag) and lithiophobic copper (Cu) in a 3D porous carbon fiber matrix, is applied on a planar Cu current collector to regulate Li plating and stripping and prevent undesired reactions. The Li-rich surface coating of lithium oxide (LiO), lithium carboxylate (RCOLi), lithium carbonates (ROCOLi), and lithium hydride (LiH) is formed by soaking and directly heating the interlayer in -butyllithium hexane solution.

Capacity Degradation of Zero-Excess All-Solid-State Li Metal Batteries Using a Poly(ethylene oxide) Based Solid Electrolyte.

Solid-state polymer electrolytes (SPEs), such as poly(ethylene oxide) (PEO), have good flexibility when compared to ceramic-type solid electrolytes. Therefore, it could be an ideal solid electrolyte for zero-excess all-solid-state Li metal battery (ZESSLB), also known as anode-free all-solid-state Li battery, development by offering better contact to the Cu current collector. However, the low Coulombic efficiencies observed from polymer type solid-state Li batteries (SSLBs) raise the concern that PEO may consume the limited amount of Li in ZESSLB to fail the system.

How microstructures, oxide layers, and charge transfer reactions influence double layer capacitances. Part 1: impedance spectroscopy and cyclic voltammetry to estimate electrochemically active surface areas (ECSAs).

Varying the electrode potential rearranges the charges in the double layer (DL) of an electrochemical interface by a resistive-capacitive current response. The capacitances of such charge relocations are frequently used in the research community to estimate electrochemical active surface areas (ECSAs), yet the reliability of this methodology is insufficiently examined. Here, the relation of capacitances and ECSAs is critically assessed with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) data on polished (Au, Ti, Ru, Pt, Ni, glassy carbon, graphite plate) and porous (carbon fleeces) electrodes.

Post-treatment strategies for pyrophoric KOH-activated carbon nanofibres.

The effect of two atmospheric post-treatment conditions directly after the KOH activation of polyacrylonitrile-based nanofibres is studied in this work. As post-treatment different N : O flow conditions, namely high O-flow and low O-flow, are applied and their impact on occurring reactions and carbon nanofibres' properties is studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Raman spectroscopy, elemental analysis and CO and Ar gas adsorption. At high O-flow conditions a pyrophoric effect was observed on the KOH-activated carbon nanofibers.

Correction to "Bimetallic Copper-Silver Catalysts for the Electrochemical Reduction of CO to Ethanol".

[This corrects the article DOI: 10.1021/acsaem.3c00985.

Li-Ion Conductivity of Single-Step Synthesized Glassy-Ceramic LiGePS and Post-heated Highly Crystalline LiGePS.

LiGePS is a phosphosulfide solid electrolyte that exhibits exceptionally high Li-ion conductivity, reaching a conductivity above 10 S cm at room temperature, rivaling that of liquid electrolytes. Herein, a method to produce glassy-ceramic LiGePS via a single-step utilizing high-energy ball milling was developed and systematically studied. During the high energy milling process, the precursors experience three different stages, namely, the 'Vitrification zone' where the precursors undergo homogenization and amorphization, 'Intermediary zone' where LiPS and LiGeS are formed, and the 'Product stage' where the desired glassy-ceramic LiGePS is formed after 520 min of milling.

Laboratory X-ray computed tomography imaging protocol allowing the operando investigation of electrode material evolution in various environments.

A robust imaging protocol utilizing laboratory XCT is presented. Hybrid 2D/3D imaging at different scales with real-time monitoring allowed to assess, in operation, the evolution of zinc electrodes within three environments, namely alkaline, near-neutral, and mildly acidic. Different combinations of currents were used to demonstrate various scenarios exhibiting both dendritic and smooth deposition of active material.

Carbonization-Temperature-Dependent Electrical Properties of Carbon Nanofibers-From Nanoscale to Macroscale.

An exact understanding of the conductivity of individual fibers and their networks is crucial to tailor the overall macroscopic properties of polyacrylonitrile (PAN)-based carbon nanofibers (CNFs). Therefore, microelectrical properties of CNF networks and nanoelectrical properties of individual CNFs, carbonized at temperatures from 600 to 1000 °C, are studied by means of conductive atomic force microscopy (C-AFM). At the microscale, the CNF networks show good electrical interconnections enabling a homogeneously distributed current flow.

Disentangling Phase and Morphological Evolution During the Formation of the Lithium Superionic Conductor Li GeP S.

The structural and morphological changes of the Lithium superionic conductor Li GeP S , prepared via a widely used ball milling-heating method over a comprehensive heat treatment range (50 - 700 °C), are investigated. Based on the phase composition, the formation process can be distinctly separated into four zones: Educt, Intermediary, Formation, and Decomposition zone. It is found that instead of Li GeS -Li PS binary crystallization process, diversified intermediate phases, including GeS in different space groups, multiphasic lithium phosphosulfides (Li P S ), and cubic Li Ge PS phase, are involved additionally during the formation and decomposition of Li GeP S .

Effect of Low Environmental Pressure on Sintering Behavior of NASICON-Type LiAlTi(PO) Solid Electrolytes: An ESEM Study.

Solid-state sintering at high temperatures is commonly used to densify solid electrolytes. Yet, optimizing phase purity, structure, and grain sizes of solid electrolytes is challenging due to the lack of understanding of relevant processes during sintering. Here, we use an environmental scanning electron microscopy (ESEM) to monitor the sintering behavior of NASICON-type LiAlTi(PO) (LATP) at low environmental pressures.

Screening of Coatings for an All-Solid-State Battery using In Situ Transmission Electron Microscopy.

With the ever-increasing use of Li-ion batteries, especially due to their adoption in electric vehicles, their safety is in prime focus. Thus, the all-solid-state batteries (ASSBs) that use solid electrolytes instead of liquid electrolytes, which reduce the risk of flammability, have been the center stage of battery research for the last few years. However, in the ASSB, the ion transportation through the solid-solid electrolyte-electrode interface poses a challenge due to contact and chemical/electrochemical stability issues.

All-Solid-State Garnet-Based Lithium Batteries at Work-In Operando TEM Investigations of Delithiation/Lithiation Process and Capacity Degradation Mechanism.

Li La Zr O (LLZO)-based all-solid-state Li batteries (SSLBs) are very attractive next-generation energy storage devices owing to their potential for achieving enhanced safety and improved energy density. However, the rigid nature of the ceramics challenges the SSLB fabrication and the afterward interfacial stability during electrochemical cycling. Here, a promising LLZO-based SSLB with a high areal capacity and stable cycle performance over 100 cycles is demonstrated.

Loss of cerebral blood flow and cerebral perfusion pressure in brain death: A transcranial Duplex ultrasonography study.

Purpose: We investigated cerebral perfusion pressure (CPP) at the time loss of cerebral blood flow (CBF) occurred during brain death (BD). We hypothesized that a critical closing pressure (CrCP) may be reached before CPP drops to 0 mmHg.

Materials And Methods: 14 patients with increasing intracranial pressure (ICP) leading to BD were included.

CO /N Separation on Highly Selective Carbon Nanofibers Investigated by Dynamic Gas Adsorption.

The development of highly selective adsorbents for CO is a key part to advance separation by adsorption as a viable technique for CO capture. In this work, polyacrylonitrile (PAN) based carbon nanofibers (CNFs) were investigated for their CO separation capabilities using dynamic gas adsorption. The CNFs were prepared by electrospinning and subsequent carbonization at various temperatures ranging from 600 to 1000 °C.

Microstructural details of spindle-like lithium titanium phosphate revealed in three dimensions.

Lithium titanium phosphate LiTi(PO) is an electrode material for lithium-ion batteries with a specific capacity of 138 mA h g. Owing to its potential of 2.5 V Li/Li it provides an electrochemically stable interface when used as an anode in all-solid state batteries with NASICON type lithium aluminium titanium phosphate electrolyte.

Active Interphase Enables Stable Performance for an All-Phosphate-Based Composite Cathode in an All-Solid-State Battery.

High interfacial resistance and unstable interphase between cathode active materials (CAMs) and solid-state electrolytes (SSEs) in the composite cathode are two of the main challenges in current all-solid-state batteries (ASSBs). In this work, the all-phosphate-based LiFePO (LFP) and Li Al Ti (PO ) (LATP) composite cathode is obtained by a co-firing technique. Benefiting from the densified structure and the formed redox-active Li Fe Ti Al (PO ) (LFTAP) interphase, the mixed ion- and electron-conductive LFP/LATP composite cathode facilitates the stable operation of bulk-type ASSBs in different voltage ranges with almost no capacity degradation upon cycling.

Ion transport and limited currents in supporting electrolytes and ionic liquids.

Supporting electrolytes contain inert dissolved salts to increase the conductivity, to change microenvironments near the electrodes and to assist in electrochemical reactions. This combined experimental and computational study examines the impact of supporting salts on the ion transport and related limited currents in electrochemical cells. A physical model that describes the multi-ion transport in liquid electrolytes and the resulting concentration gradients is presented.

[Update on Intensive Care Unit Management of Stroke].

In this review, we provide an update on the intensive care unit (ICU) management of ischemic stroke. Over the last decade, new evidence has led to rapid changes in the early management of patients admitted with acute ischemic stroke. Nevertheless, stroke remains a leading cause of disability.

The role of the double layer for the pseudocapacitance of the hydrogen adsorption on platinum.

Pseudocapacitances such as the hydrogen adsorption on platinum (HAoPt) are associated with faradaic chemical processes that appear as capacitive in their potentiodynamic response, which was reported to result from the kinetics of adsorption processes. This study discusses an alternative interpretation of the partly capacitive response of the HAoPt that is based on the proton transport of ad- or desorbed hydrogen in the double layer. Potentiodynamic perturbations of equilibrated surface states of the HAoPt lead to typical double layer responses with the characteristic resistive-capacitive relaxations that overshadow the fast adsorption kinetics.

Investigating the Interface between Ceramic Particles and Polymer Matrix in Hybrid Electrolytes by Electrochemical Strain Microscopy.

The interface between ceramic particles and a polymer matrix in a hybrid electrolyte is studied with high spatial resolution by means of Electrochemical Strain Microscopy (ESM), an Atomic Force Microscope (AFM)-based technique. The electrolyte consists of polyethylene oxide with lithium bis(trifluoromethanesulfonyl)imide (PEO-LiTFSI) and LiLaZrTaO (LLZO:Ta). The individual components are differentiated by their respective contact resonance, ESM amplitude and friction signals.

transmission electron microscopy of battery cycling: thickness dependent breaking of TiO coating on Si/SiO nanoparticles.

Conformal coating of silicon (Si) anode particles is a common strategy for improving their mechanical integrity, to mitigate battery capacity fading due to particle volume expansion, which can result in particle crumbling due to lithiation induced strain and excessive solid-electrolyte interface formation. Here, we use transmission electron microscopy in an open cell to show that TiO coatings on Si/SiO particles undergo thickness dependent rupture on battery cycling where thicker coatings crumble more readily than thinner (∼5 nm) coatings, which corroborates the difference in their capacities.

Single-Ion-Conducting "Polymer-in-Ceramic" Hybrid Electrolyte with an Intertwined NASICON-Type Nanofiber Skeleton.

The fast Li transportation of "polymer-in-ceramic" electrolytes is highly dependent on the long-range Li migration pathways, which are determined by the structure and chemistry of the electrolytes. Besides, Li dendrite growth may be promoted in the soft polymer region due to the inhomogeneous electric field caused by the commonly low Li transference number of the polymer. Herein, a single-ion-conducting polymer electrolyte is infiltrated into intertwined LiAlTi(PO) (LATP) nanofibers to construct free-standing electrolyte membranes.

The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments.

An innovative approach for the design of air electrodes for metal-air batteries are free-standing scaffolds made of electrospun polyacrylonitrile fibres. In this study, cobalt-decorated fibres are prepared, and the influence of carbonisation temperature on the resulting particle decoration, as well as on fibre structure and morphology is discussed. Scanning electron microscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, elemental analysis, and inductively coupled plasma optical emission spectrometry are used for characterisation.

Structural Study of Polyacrylonitrile-Based Carbon Nanofibers for Understanding Gas Adsorption.

Polyacrylonitrile-based carbon nanofibers (PAN-based CNFs) have great potential to be used for carbon dioxide (CO) capture due to their excellent CO adsorption properties. The porous structure of PAN-based CNFs originates from their turbostratic structure, which is composed of numerous disordered stacks of graphitic layers. During the carbonization process, the internal structure is arranged toward the ordered graphitic structure, which significantly influences the gas adsorption properties of PAN-based CNFs.