Health diagnosis and recuperation of aged Li-ion batteries with data analytics and equivalent circuit modeling.

Battery health assessment and recuperation play crucial roles in the utilization of second-life Li-ion batteries. However, due to ambiguous aging mechanisms, it is challenging to estimate battery health and devise an effective strategy for cell rejuvenation. This paper presents aging and reconditioning experiments of 62 commercial lithium iron phosphate cells, which allow us to use machine learning models to predict cycle life and identify important indicators of recoverable capacity. An average test error of 16.84% ± 1.87% (mean absolute percentage error) for cycle life prediction is achieved by gradient boosting regressor. Some of the recoverable lost capacity is found to be attributed to the non-uniformity in electrodes. An experimentally validated equivalent circuit model is built to demonstrate how such non-uniformity can be accumulated, and how it can give rise to recoverable capacity loss. Furthermore, Shapley additive explanations (SHAP) analysis also reveals that battery operation history significantly affects the capacity recovery.

Rejuvenation of aged graphite anodes from spent lithium-ion batteries via a facile surface treatment strategy.

In this study, we present a facile formic acid treatment to rejuvenate aged graphite anodes from spent lithium-ion batteries (LIBs) without damaging the electrode structure. This method effectively removes the interfacial blocking layer, improving capacity and rate performance. Our approach contributes to sustainable battery recycling strategies for spent graphite anodes in LIBs.

Whey protein powder with milk fat globule membrane attenuates Alzheimer's disease pathology in 3×Tg-AD mice by modulating neuroinflammation through the peroxisome proliferator-activated receptor γ signaling pathway.

Whey protein powder (PP), which is mainly derived from bovine milk, is rich in milk fat globule membrane (MFGM). The MGFM has been shown to play a role in promoting neuronal development and cognition in the infant brain. However, its role in Alzheimer's disease (AD) has not been elucidated. Here, we showed that the cognitive ability of 3×Tg-AD mice (a triple-transgenic mouse model of AD) could be improved by feeding PP to mice for 3 mo. In addition, PP ameliorated amyloid peptide deposition and tau hyperphosphorylation in the brains of AD mice. We found that PP could alleviate AD pathology by inhibiting neuroinflammation through the peroxisome proliferator-activated receptor γ (PPARγ)-nuclear factor-κB signaling pathway in the brains of AD mice. Our study revealed an unexpected role of PP in regulating the neuroinflammatory pathology of AD in a mouse model.

Pseudo-labeling generative adversarial networks for medical image classification.

Semi-supervised learning has become a popular technology in recent years. In this paper, we propose a novel semi-supervised medical image classification algorithm, called Pseudo-Labeling Generative Adversarial Networks (PLGAN), which only uses a small number of real images with few labels to generate fake images or mask images to enlarge the sample size of the labeled training set. First, we combine MixMatch to generate pseudo labels for the fake and unlabeled images to do the classification. Second, contrastive learning and self-attention mechanisms are introduced into PLGAN to exclude the influence of unimportant details. Third, the problem of mode collapse in contrastive learning is well addressed by cyclic consistency loss. Finally, we design global and local classifiers to complement each other with the key information needed for classification. The experimental results on four medical image datasets show that PLGAN can obtain relatively high learning performance by using few labeled and unlabeled data. For example, the classification accuracy of PLGAN is 11% higher than that of MixMatch with 100 labeled images and 1000 unlabeled images on the OCT dataset. In addition, we also conduct other experiments to verify the effectiveness of our algorithm.

Mixed Ionically/Electronically Conductive Double-Phase Interface Enhanced Solid-State Charge Transfer for a High-Performance All-Solid-State Li-S Battery.

An all-solid-state lithium-sulfur battery (ASSLSB) is a promising candidate for post-Li-ion battery technologies with high energy densities and good safety performance. However, the intrinsic insulating nature of sulfur requires triple-phase contact with an ionic conductor and an electronic conductor for electrochemical reactions, which decreases the amount of active surface and lowers the charge-transfer efficiency. In this work, a double-phase interface constructed from a mixed ionic/electronic conductor is proposed to enhance the solid-state electrochemical reaction of sulfur. By employing lithium lanthanum titanium oxide/carbon (LLTO/C) nanofibers with mixed ionic/electronic conductivity, enhanced charge-transfer behavior is realized at the sulfur-LLTO/C double-phase interface, compared to the traditional triple-phase interface. As a result, high sulfur utilization and excellent rate performance are achieved. And the facilitated charge transfer shows great potential to lower the operating temperature and improve the sulfur content for practical applications of ASSLSBs. Cycle performance is also enhanced due to the suppressed shuttle effect of polysulfides by the incorporation of the LLTO/C nanofibers.

Synthesis of tryptophan-containing 2,5-diketopiperazines via sequential C-H activation: total syntheses of tryprostatin A, maremycins A and B.

Indole 2,5-diketopiperazines (DKPs) are an important type of metabolic cyclic dipeptides containing a tryptophan (Trp) unit possessing a range of interesting biological activities. The intriguing structural features and divergent activities have stimulated tremendous efforts towards their efficient synthesis. Herein, we report the development of a unified strategy for the synthesis of three Trp-containing DKPs, namely tryprostatin A, and maremycins A and B, via a sequential C-H activation strategy. The key Trp skeletons were synthesized from the inexpensive, readily available alanine via a Pd(ii)-catalyzed ß-methyl C(sp3)-H monoarylation. A subsequent C2-selective prenylation of the resulting 6-OMe-Trp by Pd/norbornene-promoted C-H activation led to the total synthesis of tryprostatin A in 12 linear steps from alanine with 25% overall yield. Meanwhile, total syntheses of maremycins A and B were successfully accomplished using a sequential Pd-catalyzed methylene C(sp3)-H methylation as the key step in 15 linear steps from alanine.

Stabilizing a Lithium Metal Battery by an In Situ Li2S-modified Interfacial Layer via Amorphous-Sulfide Composite Solid Electrolyte.

A novel strategy has been proposed to produce in situ Li2S at the interfacial layer between lithium anode and the solid electrolyte, by using an amorphous-sulfide-LiTFSI-poly(vinylidene difluoride) (PVDF) composite solid electrolyte (SLCSE). Besides retarding the decomposition of PVDF in CSE, the Li2S-modified interfacial layer (SMIL) also improves the wettability between lithium metal and SLCSE which in turn optimizes the lithium deposition process. Our density functional theory calculation results reveal that the migration energy barrier of Li passing through SMIL is much lower than that of Li passing through LiF-modified interfacial layer (FMIL) formed from the decomposition of PVDF. The as-prepared SLCSE shows a Li ionic transference number of 0.44 and Li ion conductivity of 3.42 × 10-4 S/cm at room temperature, and the Li||SLCSE||LiFePO4 cell exhibits an outstanding rate performance with a capacity of 153, 144, 131, and 101 mAh/g at a current density of 0.05, 0.10, 0.25, and 0.50 mA/cm2, respectively.

Thermal Conductive 2D Boron Nitride for High-Performance All-Solid-State Lithium-Sulfur Batteries.

Polymer-based solid-state electrolytes are shown to be highly promising for realizing low-cost, high-capacity, and safe Li batteries. One major challenge for polymer solid-state batteries is the relatively high operating temperature (60-80 °C), which means operating such batteries will require significant ramp up time due to heating. On the other hand, as polymer electrolytes are poor thermal conductors, thermal variation across the polymer electrolyte can lead to nonuniformity in ionic conductivity. This can be highly detrimental to lithium deposition and may result in dendrite formation. Here, a polyethylene oxide-based electrolyte with improved thermal responses is developed by incorporating 2D boron nitride (BN) nanoflakes. The results show that the BN additive also enhances ionic and mechanical properties of the electrolyte. More uniform Li stripping/deposition and reversible cathode reactions are achieved, which in turn enable all-solid-state lithium-sulfur cells with superior performances.

Lithium Silicide Surface Enrichment: A Solution to Lithium Metal Battery.

The propensity of lithium dendrite formation during the charging process of lithium metal batteries is linked to inhomogeneity on the lithium surface layer. The high reactivity of lithium and the complex surface structure of the native layer create "hot spots" for fast dendritic growth. Here, it is demonstrated that a fundamental restructuring of the lithium surface in the form of lithium silicide (Lix Si) can effectively eliminate the surface inhomogeneity on the lithium surface. In situ optical microscopic study is carried out to monitor the electrochemical deposition of lithium on the Lix Si-modified lithium electrodes and the bare lithium electrode. It is observed that a much more uniform lithium dissolution/deposition on the Lix Si-modified lithium anode can be achieved as compared to the bare lithium electrode. Full cells paring the modified lithium anode with sulfur and LiFePO4 cathodes show excellent electrochemical performances in terms of rate capability and cycle stability. Compatibility of the anode enrichment method with mass production process also offers a practical way for enabling lithium metal anode for next-generation lithium batteries.

Tungsten disulfide nanosheets supported poly(xanthurenic acid) as a signal transduction interface for electrochemical genosensing applications.

Tungsten disulfide (WS2) nanosheets supported poly(xanthurenic acid) (PXa) was used as the signal transduction interface for electrochemical genosensing. The WS2 nanosheets were obtained from bulk WS2 using a simple ultrasonic method. Due to the unique physical adsorption of Xa monomers to WS2, the electropolymerization efficiency was greatly improved, accompanied with an increased electrochemical response of PXa. The obtained PXa/WS2 nanocomposite not only served as a substrate for DNA immobilization but also reflected the electrochemical transduction originating from DNA immobilization and hybridization without any other indicators or complicated labelling steps. Owing to the presence of abundant carboxyl groups, the probe ssDNA was covalently attached on the carboxyl-terminated PXa/WS2 nanocomposite through the free amines of DNA sequences based on the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydrosulfosuccinimide crosslinking reaction. The covalently immobilized probe ssDNA could selectively hybridize with its target DNA to form dsDNA on the surface of the PXa/WS2 nanocomposite. This developed biosensor achieved a satisfactory detection limit down to 1.6 × 10-16 mol L-1 and a dynamic range of 1.0 × 10-15 to 1.0 × 10-11 mol L-1 for detection of circulating tumor DNA related to gastric carcinoma. Selectivity of the biosensor has been investigated in presence of non-complementary, one-mismatched and two-mismatched DNA sequences.

In Situ Observation and Electrochemical Study of Encapsulated Sulfur Nanoparticles by MoS2 Flakes.

Sulfur is an attractive cathode material for next-generation lithium batteries due to its high theoretical capacity and low cost. However, dissolution of its lithiated product (lithium polysulfides) into the electrolyte limits the practical application of lithium sulfur batteries. Here we demonstrate that sulfur particles can be hermetically encapsulated by leveraging on the unique properties of two-dimensional materials such as molybdenum disulfide (MoS2). The high flexibility and strong van der Waals force in MoS2 nanoflakes allows effective encapsulation of the sulfur particles and prevent its sublimation during in situ TEM studies. We observe that the lithium diffusivities in the encapsulated sulfur particles are in the order of 10-17 m2 s-1. Composite electrodes made from the MoS2-encapsulated sulfur spheres show outstanding electrochemical performance, with an initial capacity of 1660 mAh g-1 and long cycle life of more than 1000 cycles.

Expeditious synthesis of pyrano[2,3,4-de]quinolines via Rh(iii)-catalyzed cascade C-H activation/annulation/lactonization of quinolin-4-ol with alkynes.

Rh(iii)-catalyzed cascade C-H activation/annulation/lactonization of quinoline-4-ols and alkynes has been reported. A broad range of tetracyclic pyrano[2,3,4-de]quinolines have been prepared in one-step with good functional group tolerance, excellent site selectivity, and high efficiency.

Palladium-catalyzed sequential monoarylation/amidation of C(sp3)-H bonds: stereoselective synthesis of α-amino-ß-lactams and anti-α,ß-diamino acid.

Pd-Catalyzed sequential monoarylation/amidation of C(sp3)-H bonds of alanine enabled by a removable 5-methoxyquinolin-8-amine (MQ) auxiliary is described. This process is highly efficient and compatible with a variety of functional groups, providing a general and practical access to various α-amino-ß-lactams. The synthetic potential of this protocol is further demonstrated by the stereoselective synthesis of orthogonally protected anti-α,ß-diamino acids.

Stereoselective alkoxycarbonylation of unactivated C(sp3)-H bonds with alkyl chloroformates via Pd(II)/Pd(IV) catalysis.

Several examples on Pd-catalysed carbonylation of methyl C(sp3)-H bonds with gaseous CO via Pd(II)/Pd(0) catalysis have been reported. However, methylene C(sp3)-H carbonylation remains a great challenge, largely due to the lack of reactivity of C-H bonds and the difficulty in CO migratory insertion. Herein, we report the stereoselective alkoxycarbonylation of both methyl and methylene C(sp3)-H bonds with alkyl chloroformates through a Pd(II)/Pd(IV) catalytic cycle. A broad range of aliphatic carboxamides and alkyl chloroformates are compatible with this protocol. In addition, this process is scalable and the directing group could be easily removed under mild conditions with complete retention of configuration.

Influence of Ligands on the Formation of Kesterite Thin Films for Solar Cells: A Comparative Study.

The preparation of solar-cell-grade Cu2 ZnSnS4 (CZTS) thin films from ligand-capped small-grained CZTS particles remains hindered by problems of phase segregation, composition non-uniformity, and in particular carbon-layer formation. Herein, through a systematic comparative study of annealed films of CZTS nanocrystals prepared using conventional oleylamine and those prepared using formamide, these problems are found to be mainly attributable to the influence of the ligands, and mechanisms are proposed. Importantly, the origin of the carbon layer in oleylamine-capped CZTS films is revealed to be the reaction between oleylamine and sulfur. This carbon layer has a very poor electrical conductivity, which can be the reason for the limited performance of such films. Fortunately, these problems can almost all be avoided by replacing oleylamine with formamide to form CZTS films.

Chemical insights into the roles of nanowire cores on the growth and supercapacitor performances of Ni-Co-O/Ni(OH)2 core/shell electrodes.

Nanostructured core/shell electrodes have been experimentally demonstrated promising for high-performance electrochemical energy storage devices. However, chemical insights into the significant roles of nanowire cores on the growth of shells and their supercapacitor behaviors still remain as a research shortfall. In this work, by substituting 1/3 cobalt in the Co3O4 nanowire core with nickel, a 61% enhancement of the specific mass-loading of the Ni(OH)2 shell, a tremendous 93% increase of the volumetric capacitance and a superior cyclability were achieved in a novel NiCo2O4/Ni(OH)2 core/shell electrode in contrast to a Co3O4/Ni(OH)2 one. A comparative study suggested that not only the growth of Ni(OH)2 shells but also the contribution of cores were attributed to the overall performances. Importantly, their chemical origins were revealed through a theoretical simulation of the core/shell interfacial energy changes. Besides, asymmetric supercapacitor devices and applications were also explored. The scientific clues and practical potentials obtained in this work are helpful for the design and analysis of alternative core/shell electrode materials.

(CH3 NH3 )2 PdCl4 : A Compound with Two-Dimensional Organic-Inorganic Layered Perovskite Structure.

The synthesis of previously unknown perovskite (CH3 NH3 )2 PdCl4 is reported. Despite using an organic cation with the smallest possible alkyl group, a 2D organic-inorganic layered Pd-based perovskites was still formed. This demonstrates that Pd-based 2D perovskites can be obtained even if the size of the organic cation is below the size limit predicted by the Goldschmidt tolerance-factor formula. The (CH3 NH3 )2 PdCl4 phase has a bulk resistivity of 1.4â€…Ω cm, a direct optical gap of 2.22 eV, and an absorption coefficient on the order of 104  cm-1 . XRD measurements suggest that the compound is moderately stable in air, an important advantage over several existing organic-inorganic perovskites that are prone to phase degradation problems when exposed to the atmosphere. Given the recent interest in organic-inorganic perovskites, the synthesis of this new Pd-based organic-inorganic perovskite may be helpful in the preparation and understanding of other organic-inorganic perovskites.

Catalyst-Controlled Amino- versus Oxy-Acetoxylation of Urea-Tethered Alkenes: Efficient Synthesis of Cyclic Ureas and Isoureas.

A catalyst-controlled vicinal amino- versus oxy-acetoxylation of alkenes with PhI(OAc)2 as the oxidant is described. The divergent synthesis of cyclic ureas and isoureas was achieved in good yields under mild conditions employing ambident urea nucleophiles. Both terminal and internal alkenes are compatible with this reaction protocol.

Stereoselective Synthesis of Chiral ß-Fluoro α-Amino Acids via Pd(II)-Catalyzed Fluorination of Unactivated Methylene C(sp(3))-H Bonds: Scope and Mechanistic Studies.

The synthesis of fluorinated complex molecules via direct C(sp(3))-H fluorination is attractive yet remains challenging. Here we describe the Pd(II)-catalyzed fluorination of unactivated methylene C(sp(3))-H bonds by an inner-sphere mechanism. This method allows the site- and diastereoselective fluorination of ß-methylene C(sp(3))-H bonds of α-amino acid derivatives. A range of substrates containing both aliphatic and benzylic C(sp(3))-H bonds were compatible with this protocol, leading to an array of ß-fluorinated α-amino acids. Stoichiometric fluorination of an isolated palladacycle intermediate takes place rapidly under very mild reaction conditions (room temperature, 5-10 min). Data from preliminary mechanistic studies are consistent with direct C-F reductive elimination from a high-valent intermediate.

Hyperbaric Oxygen Preconditioning Attenuates Myocardium Ischemia-Reperfusion Injury Through Upregulation of Heme Oxygenase 1 Expression: PI3K/Akt/Nrf2 Pathway Involved.

BACKGROUND: With the rise of the burden of ischemic heart disease, both clinical and economic evidence show a desperate need to protect the heart against myocardium ischemia-reperfusion injury-related complications following cardiac surgery or percutaneous coronary intervention. However, there is no effective intervention for myocardium ischemia-reperfusion injury as yet. METHODS: We pretreated mice with 4 daily 2.0 absolute atmosphere (ATA) hyperbaric oxygen, then observed its effects on heart function parameters and infarct size following in situ ischemia-reperfusion. Multiple oxidative and inflammation products were measured in the myocardium. Next, we investigated the expression of heme oxygenase 1 (HO-1), phosphatidylinositol 3-kinase (PI3K)/serine/threonine protein kinase (Akt) pathway, and NF-E2-related factor 2 (Nrf2) in the presence of myocardium ischemia-reperfusion injury, hyperbaric oxygen preconditioning, and their inhibitors and their effects on heart function parameters. RESULTS: Hyperbaric oxygen preconditioning ameliorated the cardiac function and histological alterations induced by myocardium ischemia-reperfusion injury, decreased oxidative products and proinflammatory cytokine. Hyperbaric oxygen preconditioning increased expression of HO-1, which was suppressed by PI3K inhibitor LY294002, Nrf2 knockout, and Akt inhibitor triciribine. The expression of Nrf2 was enhanced by hyperbaric oxygen preconditioning, but decreased by LY294002 and triciribine. The Akt was also activated by hyperbaric oxygen preconditioning but suppressed by LY294002. The hemodynamic assays showed that cardiac function was suppressed by LY294002, Nrf2 knockout, and triciribine. CONCLUSION: These data present a novel signaling mechanism by which hyperbaric oxygen preconditioning protects myocardium ischemia-reperfusion injury via PI3K/Akt/Nrf2-dependent antioxidant defensive system.