Mechanistic insights into the reversible lithium storage in an open porous carbon via metal cluster formation in all solid-state batteries

Porous carbons are promising anode materials for next generation lithium batteries due to their large lithium storage capacities. However, their highsloping capacity during lithiation and delithiation as well as capacity fading due to intense formation of solid electrolyte interphase (SEI) limit their gravimetric and volumetric energy densities. Herein we compare a microporous carbide derived carbon material (MPC) as promising future anode for all solid state batteries with a commercial high performance hard carbon anode. The MPC obtains high and reversible lithiation capacities of 1000 mAh g 1 carbon in half cells exhibiting an extended plateau region near 0 V vs. Li/Liþ preferable for full cell application. The well defined microporosity of the MPC with a specific surface area of >1500 m2 g 1 combines well with the argyrodite type electrolyte (Li6PS5Cl) suppressing extensive SEI formation to deliver high coulombic efficiencies. Preliminary full cell measurements vs. nickel rich NMC cathodes (LiNi0.9Co0.05Mn0.05O2) provide a considerably improved average potential of 3.76 V leading to a projected energy density as high as 449 Wh kg 1 and reversible cycling for more than 60 cycles. 7Li Nuclear Magnetic Resonance spectroscopy was combined with ex situ Small Angle X ray Scattering to elucidate the storage mechanism of lithium inside the carbon matrix. The formation of extended quasi metallic lithium clusters after electrochemical lithiation was revealed

High-Capacity Reversible Lithium Storage in Defined Microporous Carbon Framework for All Solid-State Lithium Batteries

For decades graphite has been used as the anode material of choice for lithium batteries since porous carbons were believed to be inappropriate because of their high potential slope during lithiation as well as capacity losses due to intense formation of solid electrolyte interphase (SEI). However, in this work we demonstrate a microporous carbide-derived carbon material (HCmicro) to provide a high-capacity anode framework for lithium storage in all solid-state batteries. Half-cell measurements of HCmicro exhibit exceptionally high and reversible lithiation capacities of 1000 mAh g-1carbon utilizing an extremely long voltage plateau near 0 V vs. Li/Li+. The defined microporosity of the HCmicro combined well with the argyrodite-type electrolyte (Li6PS5Cl) suppressing extensive SEI formation to deliver high coulombic efficiencies. Preliminary full-cell measurements vs. NMC-cathodes (LiNi0.9Co0.05Mn0.05O2) obtained a considerably improved average potential of 3.76 V leading to a projected energy density as high as 443 Wh kg-1. 7Li Nuclear Magnetic Resonance spectroscopy was combined with ex-situ Small Angle X-ray Scattering and further electrochemical investigations to elucidate the storage mechanism of lithium inside the carbon matrix revealing the formation of extended quasi-metallic lithium clusters

Porous Dithiine-Linked Covalent Organic Framework as a Dynamic Platform for Covalent Polysulfide Anchoring in Lithium-Sulfur Battery Cathodes

Dithiine linkage formation via a dynamic and self-correcting nucleophilic aromatic substitution reaction enables the de novo synthesis of a porous thianthrene-based two-dimensional covalent organic framework (COF). For the first time, this organo-sulfur moiety is integrated as a structural building block into a crystalline layered COF. The structure of the new material deviates from the typical planar interlayer π-stacking of the COF to form undulated layers caused by bending along the C-S-C bridge, without loss of aromaticity and crystallinity of the overall COF structure. Comprehensive experimental and theoretical investigations of the COF and a model compound, featuring the thianthrene moiety, suggest partial delocalization of sulfur lone pair electrons over the aromatic backbone of the COF decreasing the band gap and promoting redox activity. Postsynthetic sulfurization allows for direct covalent attachment of polysulfides to the carbon backbone of the framework to afford a molecular-designed cathode material for lithium-sulfur (Li-S) batteries with a minimized polysulfide shuttle. The fabricated coin cell delivers nearly 77% of the initial capacity even after 500 charge-discharge cycles at 500 mA/g current density. This novel sulfur linkage in COF chemistry is an ideal structural motif for designing model materials for studying advanced electrode materials for Li-S batteries on a molecular level

Multisensory integration and ADHD-like traits : evidence for an abnormal temporal integration window in ADHD

Abnormalities in multimodal processing have been found in many developmental disorders such as autism and dyslexia. However, surprisingly little empirical work has been conducted to test the integrity of multisensory integration in Attention Deficit Hyperactivity Disorder (ADHD). The main aim of the present study was to examine links between symptoms of ADHD (as measured using a self-report scale in a healthy adult population) and the temporal aspects of multisensory processing. More specifically, a Simultaneity Judgement (SJ) and a Temporal Order Judgement (TOJ) task were used in participants with low and high levels of ADHD-like traits to measure the temporal integration window and Just-Noticeable Difference (JND) (respectively) between the timing of an auditory beep and a visual pattern presented over a broad range of stimulus onset asynchronies. The Point of Subjective Similarity (PSS) was also measured in both cases. In the SJ task, participants with high levels of ADHD-like traits considered significantly fewer stimuli to be simultaneous than participants with high levels of ADHD-like traits, and the former were found to have significantly smaller temporal windows of integration (although no difference was found in the PSS in the SJ or TOJ tasks, or the JND in the latter). This is the first study to identify an abnormal temporal integration window in individuals with ADHD-like traits. Perceived temporal misalignment of two or more modalities can lead to distractibility (e.g., when the stimulus components from different modalities occur separated by too large of a temporal gap). Hence, an abnormality in the perception of simultaneity could lead to the increased distractibility seen in ADHD