Data-Driven Insight into the Reductive Stability of Ion-Solvent Complexes in Lithium Battery Electrolytes.

Lithium (Li) metal batteries (LMBs) are regarded as one of the most promising energy storage systems due to their ultrahigh theoretical energy density. However, the high reactivity of the Li anodes leads to the decomposition of the electrolytes, presenting a huge impediment to the practical application of LMBs. The routine trial-and-error methods are inefficient in designing highly stable solvent molecules for the Li metal anode. Herein, a data-driven approach is proposed to probe the origin of the reductive stability of solvents and accelerate the molecular design for advanced electrolytes. A large database of potential solvent molecules is first constructed using a graph theory-based algorithm and then comprehensively investigated by both first-principles calculations and machine learning (ML) methods. The reductive stability of 99% of the electrolytes decreases under the dominance of ion-solvent complexes, according to the analysis of the lowest unoccupied molecular orbital (LUMO). The LUMO energy level is related to the binding energy, bond length, and orbital ratio factors. An interpretable ML method based on Shapley additive explanations identifies the dipole moment and molecular radius as the most critical descriptors affecting the reductive stability of coordinated solvents. This work not only affords fruitful data-driven insight into the ion-solvent chemistry but also unveils the critical molecular descriptors in regulating the solvent's reductive stability, which accelerates the rational design of advanced electrolyte molecules for next-generation Li batteries.

Probing the Origin of Viscosity of Liquid Electrolytes for Lithium Batteries.

Viscosity is an extremely important property for ion transport and wettability of electrolytes. Easy access to viscosity values and a deep understanding of this property remain challenging yet critical to evaluating the electrolyte performance and tailoring electrolyte recipes with targeted properties. We proposed a screened overlapping method to efficiently compute the viscosity of lithium battery electrolytes by molecular dynamics simulations. The origin of electrolyte viscosity was further comprehensively probed. The viscosity of solvents exhibits a positive correlation with the binding energy between molecules, indicating viscosity is directly correlated to intermolecular interactions. Salts in electrolytes enlarge the viscosity significantly with increasing concentrations while diluents serve as the viscosity reducer, which is attributed to the varied binding strength from cation-anion and cation-solvent associations. This work develops an accurate and efficient method for computing the electrolyte viscosity and affords deep insight into viscosity at the molecular level, which exhibits the huge potential to accelerate advanced electrolyte design for next-generation rechargeable batteries.

An Electrocatalytic Model of the Sulfur Reduction Reaction in Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) battery is strongly considered as one of the most promising energy storage systems due to its high theoretical energy density and low cost. However, the sluggish reduction kinetics from Li2 S4 to Li2 S during discharge hinders the practical application of Li-S batteries. Although various electrocatalysts have been proposed to improve the reaction kinetics, the electrocatalytic mechanism is unclear due to the complexity of sulfur reduction reactions (SRR). It is crucial to understand the electrocatalytic mechanism thoroughly for designing advanced electrocatalysts. Herein an electrocatalytic model is constructed to reveal the chemical mechanism of the SRR in Li-S batteries based on systematical density functional theory calculations, taking heteroatoms-doped carbon materials as an example. The adsorption energy of LiSy ⋅ (y=1, 2, or 3) radicals is used as a key descriptor to predict the reaction pathway, rate-determining step, and overpotential. A diagram for designing advanced electrocatalysts is accordingly constructed. This work establishes a theoretical model, which is an intelligent integration for probing the complicated SRR mechanisms and designing advanced electrocatalysts for high-performance Li-S batteries.

Comparative Efficacy and Acceptability of Endoscopic Methods for Rectal Neuroendocrine Neoplasms with Low Malignant Potential: A Network Meta-analysis.

BACKGROUND/AIMS:  Although endoscopic resection is an effective treatment of rectal neuroendocrine neoplasms (R-NENs) with low malignant potential, there is no consensus on the most recommended endoscopic method. This study aimed to assess the efficacy and acceptability of different endoscopic treatments for R-NENs with low malignant potential. MATERIALS AND METHODS:  We searched databases for studies on treatments of R-NENs using endoscopic resection. These studies comprised techniques such as endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), modified endoscopic mucosal resection (EMRM), modified endoscopic submucosal dissection (ESDM), and transanal endoscopic microsurgery (TEM). The primary outcomes assessed were histological complete resection (HCR). RESULTS:  Overall, 38 retrospective studies (3040 R-NENs) were identified. Endoscopic mucosal resection with a cap (EMRC), endoscopic mucosal resection with ligation (EMRL), ESD, ESDM, and TEM demonstrated higher resectability than did EMR in achieving HCR. Endoscopic mucosal resection, EMRC, EMRL, EMRP, EMRD, and EMRU required shorter operation times than did ESD. Endoscopic mucosal resection, EMRC, ESDM, and TEM incurred lower risks than did ESD. CONCLUSION:  Regarding R-NENs <20 mm with low malignant potential, ESD could be used as the primary treatment. However, TEM may be more effective if supported by economic conditions and hospital facility. With respect to R-NENs <16 mm with low malignant potential, EMRL could be used as the primary treatment. In regard to R-NENs <10 mm with low malignant potential, EMRL, EMRC, and ESD could be used as the primary treatment. However, EMRL and EMRC might be better when operational difficulties and economic conditions were considered.

Solvation Regulation Reinforces Anion-Derived Inorganic-Rich Interphase for High-Performance Quasi-Solid-State Li Metal Batteries.

Solid-state polymer lithium metal batteries are an important strategy for achieving high safety and high energy density. However, the issue of Li dendrites and inherent inferior interface greatly restricts practical application. Herein, this study introduces tris(2,2,2-trifluoroethyl)phosphate solvent with moderate solvation ability, which can not only complex with Li+ to promote the in-situ ring-opening polymerization of 1,3-dioxolane (DOL), but also build solvated structure models to explore the effect of different solvation structures in the polymer electrolyte. Thereinto, it is dominated by the contact ion pair solvated structure with pDOL chain segments forming less lithium bonds, exhibiting faster kinetic process and constructing a robust anion-derived inorganic-rich interphase, which significantly improves the utilization rate of active Li and the high-voltage resistance of pDOL. As a result, it exhibits stable cycling at ultra-high areal capacity of 20 mAh cm-2 in half cells, and an ultra-long lifetime of over 2000 h in symmetric cells can be realized. Furthermore, matched with LiNi0.9Co0.05Mn0.05O2 cathode, the capacity retention after 60 cycles is as high as 96.8% at N/P value of 3.33. Remarkably, 0.7 Ah Li||LiNi0.9Co0.05Mn0.05O2 pouch cell with an energy density of 461 Wh kg-1 can be stably cycled for five cycles at 100% depth of discharge.

Unveiling the unprecedented catalytic capability of micro-sized Co-ZIF-L for the thermal decomposition of RDX by 2D-structure-induced mechanism reversal.

Developing MOF-based catalysts with superior catalytic properties for the thermal decomposition of cyclotrimethylenetrinitramine (RDX) is significant for the application of novel and efficient combustion catalysts oriented to RDX-based propellants with excellent combustion performance. Herein, micro-sized Co-ZIF-L with a star-like morphology (SL-Co-ZIF-L) was found to exhibit unprecedented catalytic capability for the decomposition of RDX, which can lower the decomposition temperature of RDX by 42.9 °C and boost the heat release by 50.8%, superior to that of all the ever-reported MOFs and even ZIF-67, which has similar chemical composition but a much smaller size. In-depth mechanism study from both experimental and theoretical views reveals that the weekly interacted 2D layered structure of SL-Co-ZIF-L could activate the exothermic C-N fission pathway for the decomposition of RDX in the condensed phase, thus reversing the commonly advantageous N-N fission pathway and promoting the decomposition process in the low-temperature stage. Our study reveals the unusually superior catalytic capability of micro-sized MOF catalysts and sheds light on the rational structure design of catalysts used in micromolecule transformation reactions, typically the thermal decomposition of energetic materials.

[Symptomatic Profiles of 173 Chinese Patients with Essential Thrombocythemia].

OBJECTIVE: To explore the symptomatic burden of patients with essential thrombocythemia (ET) and its relation with clinical characteristics including the mutation status, therapeutic protocols and sex. METHODS: Total of 173 Chinese ET patients were selected and grouped on the basis of disease characteristics (mutation status, therapeutic pro to- cols, and sex). RESULTS: All the groups showed low-to-high symptom burden, with the highest in the Hu (hydroxyurea)-group (total symptom score [TSS], 14.7; range, 7.6-14.7). In the JAK2V617F-positive, Hu-treated, and female groups TSS and independent symptom scores were higher than those in the control group. The CALR-positive and IFN-α-treated groups had lower overall and individual scores as compared with groups lacking the corresponding characteristics. As the number of characteristics (JAK2V617F-positive, Hu-treated, and female) increases, the severity of symptoms gradually increased. CONCLUSION: The different characteristics have various effects on symptom burden in ET patients. The accumulation of certain characteristics will lead to more severe symptom burden, thus the patient＇s symptom burden should be considered comprehensively when making up the treatment schemes and prognosis.