Recognition of eye diseases based on deep neural networks for transfer learning and improved D-S evidence theory.

BACKGROUND: Human vision has inspired significant advancements in computer vision, yet the human eye is prone to various silent eye diseases. With the advent of deep learning, computer vision for detecting human eye diseases has gained prominence, but most studies have focused only on a limited number of eye diseases. RESULTS: Our model demonstrated a reduction in inherent bias and enhanced robustness. The fused network achieved an Accuracy of 0.9237, Kappa of 0.878, F1 Score of 0.914 (95% CI [0.875-0.954]), Precision of 0.945 (95% CI [0.928-0.963]), Recall of 0.89 (95% CI [0.821-0.958]), and an AUC value of ROC at 0.987. These metrics are notably higher than those of comparable studies. CONCLUSIONS: Our deep neural network-based model exhibited improvements in eye disease recognition metrics over models from peer research, highlighting its potential application in this field. METHODS: In deep learning-based eye recognition, to improve the learning efficiency of the model, we train and fine-tune the network by transfer learning. In order to eliminate the decision bias of the models and improve the credibility of the decisions, we propose a model decision fusion method based on the D-S theory. However, D-S theory is an incomplete and conflicting theory, we improve and eliminate the existed paradoxes, propose the improved D-S evidence theory(ID-SET), and apply it to the decision fusion of eye disease recognition models.

Heavy Metal Contamination Characteristics in Acid Soil-rice Systems and the Corresponding Human Health Risk in a Mining and Smelting Area in Jiangxi Province.

To understand the effects of mining activities on soil cadmium and rice, a typical mining area was selected. The Cd content in a considerable number of soils exceeded the standard limitation GB/T 36,783 - 2018, with a rate of 42.03%. Further analysis revealed soil total Cd content was strongly correlated with soil bioavailability of Cd (R2 0.721**), pH (R2 0.386**) and soil total content of lead(R2 0.678**). It suggests that soil total Cd content and soil pH significantly affect rice Cd levels, and that acid soil increases soil Cd bioavailability [Soil Cd (B)] and accumulation in rice grain. Furthermore, a mathematical dynamic fitting is developed to describe the relationship between rice Cd content, soil pH, and soil Cd bioavailability in acidic soil (pH 5-5.5). Rice Cd content (mg/kg) = - 179.2 + 67.24 × (Soil pH) - 12.81× [Soil Cd (B)] - 6.28 × 153(Soil pH) 2 + 65.79 × [Soil Cd (B)]2. This study identifies the main types of pollutants emitted by industrial activities and recommends Cd as the most concerning pollutant for rice planting and paddy soil.

Regulating cathode surface hydroxyl chemistry enables superior potassium storage.

Potassium vanadium fluorophosphate (KVPO4F) is regarded as a promising cathode candidate for potassium-ion batteries due to its high working voltage and satisfactory theoretical capacity. However, the usage of electrochemically inactive binders and redundant current collectors typically results in inferior electrochemical performance and low energy density, thus implying the important role of rational electrode structure design. Herein, we have reported a scalable and cost-effective synthesis of a cellulose-derived KVPO4F self-supporting electrode, which features a special surface hydroxyl chemistry, three-dimensional porous and conductive framework, as well as super flexible and stable architecture. The cellulose not only serves as a flexible substrate, a pore-forming agent, and a versatile binder for KVPO4F/conductive carbon but also enhances the K-ion migration ability. Benefiting from the special hydroxyl chemistry-induced storage mechanism and electrode structural stability, the flexible freestanding KVPO4F cathode exhibits high-rate performance (53.0% capacity retention with current densities increased 50-fold, from 0.2 C to 10 C) and impressive cycling stability (capacity retention up to 74.9% can be achieved over 1,000 cycles at a rate of 5 C). Such electrode design and surface engineering strategies, along with a deeper understanding of potassium storage mechanisms, provide invaluable guidance for better electrode design to boost the performance of potassium-ion energy storage systems.

Liquid-Like Li-Ion Conduction in Oxides Enabling Anomalously Stable Charge Transport across the Li/Electrolyte Interface in All-Solid-State Batteries.

The softness of sulfur sublattice and rotational PS4 tetrahedra in thiophosphates result in liquid-like ionic conduction, leading to enhanced ionic conductivities and stable electrode/thiophosphate interfacial ionic transport. However, the existence of liquid-like ionic conduction in rigid oxides remains unclear, and modifications are deemed necessary to achieve stable Li/oxide solid electrolyte interfacial charge transport. In this study, by combining the neutron diffraction survey, geometrical analysis, bond valence site energy analysis, and ab initio molecular dynamics simulation, 1D liquid-like Li-ion conduction is discovered in LiTa2 PO8 and its derivatives, wherein Li-ion migration channels are connected by four- or five-fold oxygen-coordinated interstitial sites. This conduction features a low activation energy (0.2 eV) and short mean residence time (<1 ps) of Li ions on the interstitial sites, originating from the Li-O polyhedral distortion and Li-ion correlation, which are controlled by doping strategies. The liquid-like conduction enables a high ionic conductivity (1.2 mS cm-1 at 30 °C), and a 700 h anomalously stable cycling under 0.2 mA cm-2 for Li/LiTa2 PO8 /Li cells without interfacial modifications. These findings provide principles for the future discovery and design of improved solid electrolytes that do not require modifications to the Li/solid electrolyte interface to achieve stable ionic transport.

Building K-C Anode with Ultrahigh Self-Diffusion Coefficient for Solid State Potassium Metal Batteries Operating at -20 to 120 °C.

Solid state potassium (K) metal batteries are intriguing in grid-scale energy storage, benefiting from the low cost, safety, and high energy density. However, their practical applications are impeded by poor K/solid electrolyte (SE) interfacial contact and limited capacity caused by the low K self-diffusion coefficient, dendrite growth, and intrinsically low melting point/soft features of metallic K. Herein, a fused-modeling strategy using potassiophilic carbon allotropes molted with K is demonstrated that can enhance the electrochemical performance/stability of the system via promoting K diffusion kinetics (2.37 × 10-8 cm2 s-1 ), creating a low interfacial resistance (≈1.3 Ω cm2 ), suppressing dendrite growth, and maintaining mechanical/thermal stability at 200 °C. A homogeneous/stable K stripping/plating is consequently implemented with a high current density of 2.8 mA cm-2 (at 25 °C) and a record-high areal capacity of 11.86 mAh cm-2 (at 0.2 mA cm-2 ). The enhanced K diffusion kinetics contribute to sustaining intimate interfacial contact, stabilizing the stripping/plating at high current densities. Full cells coupling ultrathin K-C composite anodes (≈50 µm) with Prussian blue cathodes and ß/ß″-Al2 O3 SEs deliver a high energy density of 389 Wh kg-1 with a retention of 94.4% after 150 cycles and fantastic performances at -20 to 120 °C.

The Mycobacterium tuberculosis prolyl dipeptidyl peptidase cleaves the N-terminal peptide of the immunoprotein CXCL-10.

Dipeptidyl peptidases constitute a class of non-classical serine proteases that regulate an array of biological functions, making them pharmacologically attractive enzymes. With this work, we identified and characterized a dipeptidyl peptidase from Mycobacterium tuberculosis (MtDPP) displaying a strong preference for proline residues at the P1 substrate position and an unexpectedly high thermal stability. MtDPP was also characterized with alanine replacements of residues of its active site that yielded, for the most part, loss of catalysis. We show that MtDPP catalytic activity is inhibited by well-known human DPP4 inhibitors. Using MALDI-TOF mass spectrometry we also describe that in vitro, MtDPP mediates the truncation of the C-X-C motif chemokine ligand 10, indicating a plausible role in immune modulation for this mycobacterial enzyme.

Effect of Different Initial CaO/SiO2 Molar Ratios and Curing Times on the Preparation and Formation Mechanism of Calcium Silicate Hydrate.

To better understand the pozzolanic activity in fly ash used as a supplementary cementitious material in cement or concrete, calcium silicate hydrate (C-S-H) has been synthesized by adding silica fume to a supersaturated calcium hydroxide solution prepared by mixing calcium oxide and ultrapure water. Thermogravimetric analysis results have revealed the variation in the weight loss due to C-S-H in the samples and the conversion ratio of calcium oxide (the µCaO value), which represents the proportion of calcium oxide in the initial reaction mixture used to produce C-S-H, with curing time. The weight loss due to C-S-H and the µCaO value were both maximized (13.5% and 90.4%, respectively) when the initial C/S molar ratio was 1.0 and the curing time was 90 d. X-ray diffraction (XRD) analysis has indicated that C-S-H in the samples after curing for 7 d had the composition Ca1.5SiO3.5·xH2O. 29Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) analysis has revealed that the degree of polymerization of C-S-H increased with an increase in curing time for samples with an initial C/S molar ratio of 1.0. The ratio of internal to terminal tetrahedra (Q2/Q1) increased from 2.29 to 4.28 with the increase in curing time from 7 d to 90 d. At curing times ≥ 28 d, a leaf-like C-S-H structure was observed by scanning electron microscopy (SEM). An ectopic nucleation-polymerization reaction process is proposed for the formation mechanism of C-S-H.

A simplified multiplex methylated DNA testing for early detection of colorectal cancer in stool DNA.

BACKGROUND: ColoDefense1.0 assay has demonstrated its excellent sensitivity and specificity for early detection of colorectal cancer (CRC) by detecting the methylation levels of SDC2 and SEPT9, while exhibited limitations on relatively large sample capacity required and limited detection throughput by applying triplicate PCR reactions for each sample. In this study, ColoDefense1.0 was simplified and optimized into ColoDefense2.0 in a single PCR reaction. METHODS: A total 529 stool specimens were collected, and 244 CRC patients, 34 patients with advanced adenomas (AA), 64 with small polyps (SP) and 187 control subjects were divided in training and validation cohorts. Methylation levels of SEPT9 and SDC2 were examined by qPCR reactions in triplicate or single. RESULTS: The stool DNA quantity stored in preservative buffer at 37 °C up to 7 days exhibited no significant decrease. In the training cohort, when the number of replicates reduced from 3 to 1, the overall performance of ColoDefense2.0 was identical to that of ColoDefense1.0, showing sensitivities of 71.4% for AA and 90.8% for all stage CRC with a specificity of 92.9%. In the validation cohort, sensitivities of SP, AA and CRC using ColoDefense2.0 were 25.0%, 55.0% and 88.2%, increased from 14.1% (20.3%), 40.0% (40.0%) and 79.4% (67.6%) using SDC2 (SEPT9) alone; along with an overall specificity of 90.2%, decreased from 94.1% (95.1%) using SDC2 (SEPT9) alone. CONCLUSION: The simplified ColoDefense test maintained the overall performance while reduced the number of PCR reactions to 1/3, and provided an effective and convenient tool to detect early CRC and precancerous lesions and potentially improve the compliance of screening.

Management and prevention of brachial plexus injury caused by surgical suture of neck dissection induced chylous fistula.

BACKGROUND: The complication of brachial plexus injury (BPI) after surgical suture of chylous fistula caused by neck dissection is extremely rare. For the first time, we investigated the treatment and prevention strategy of BPI caused by surgical suture of neck dissection induced chylous fistula. METHODS: Forty-two patients undergoing surgical suture of neck dissection induced chylous fistula were identified between January 2015 to March 2022 at a single tertiary academic center. All patients were divided into two groups, medial anterior scalene muscle (MASM) group (24 patients) and lateral anterior scalene muscle (LASM) group (18 patients), according to the location of fistula regarding scalene muscle described in the surgical records. The incidence of BPI between the two groups after surgical suture was summarized and compared. RESULTS: There was significant difference in the incidence of different degrees of BPI between the two groups. In the MASM group, the incidence of BPI was 0 % (0/24), while in the LASM group, 6 cases suffered different degrees of BPI immediately after operation and the incidence of BPI was 33.3 % (6/18) (p < 0.05). The neurological function of all BPI cases recovered within 1-3 months after the suture was removed in time. CONCLUSION: The incidence of BPI in patients of LASM group was significantly higher than that of MASM group. When suturing this kind of fistula, the depth of the needle should be properly controlled to avoid BPI. In case of BPI, the suture should be removed as soon as possible to promote the recovery of neurological function.

Kinase expression enhances phenolic aldehydes conversion and ethanol fermentability of Zymomonas mobilis.

Kinases modulate the various physiological activities of microbial fermenting strains including the conversion of lignocellulose-derived phenolic aldehydes (4-hydroxyaldehyde, vanillin, and syringaldehyde). Here, we comprehensively investigated the gene transcriptional profiling of the kinases under the stress of phenolic aldehydes for ethanologenic Zymomonas mobilis using DNA microarray. Among 47 kinase genes, three genes of ZMO0003 (adenylylsulfate kinase), ZMO1162 (histidine kinase), and ZMO1391 (diacylglycerol kinase), were differentially expressed against 4-hydroxybenzaldehyde and vanillin, in which the overexpression of ZMO1162 promoted the phenolic aldehydes conversion and ethanol fermentability. The perturbance originated from plasmid-based expression of ZMO1162 gene contributed to a unique expression profiling of genome-encoding genes under all three phenolic aldehydes stress. Differentially expressed ribosome genes were predicted as one of the main contributors to phenolic aldehydes conversion and thus finally enhanced ethanol fermentability for Z. mobilis ZM4. The results provided an insight into the kinases on regulation of phenolic aldehydes conversion and ethanol fermentability for Z. mobilis ZM4, as well as the target object for rational design of robust biorefinery strains.

Preoperative tracheotomy in the treatment of upper airway obstruction of patients with advanced stage supraglottic carcinoma.

BACKGROUND: Preoperative tracheotomy is an effective option that secures upper airway patency in laryngeal carcinoma patients suffering from upper airway obstruction, but the influence of this treatment on oncologic outcomes of laryngeal carcinoma remains controversial. The purpose of this study was to determine the impact of preoperative tracheotomy on overall survival in supraglottic carcinoma patients with tumor obstruction of the upper airway, and explore the potential causes. MATERIALS AND METHODS: This retrospective study collected 243 consecutive patients with advanced stage supraglottic carcinoma from 2005 to 2010. Preoperative tracheotomy in the management of upper airway obstruction in patients with supraglottic carcinoma was analyzed. RESULTS: The mean age was 60.9 years at diagnosis, with men accounting for 98.4% of all patients. Thirty nine (16.0%) patients presenting with tumor obstruction of the upper airway required preoperative tracheotomy. T4 stage patients had higher rate of tracheotomy than those of patients with T3 stage (36.8% vs 12.2%). Patients with upper airway obstruction presented with greater tumor area compared with patients without (13.7 cm2 vs 9.0 cm2). The optimal cutoff value of tumor area for tracheotomy and OS rate were both at 10 cm2. Supraglottic patients with upper airway obstruction receiving preoperative tracheotomy had poorer OS rate compared with patients without. T stage and tumor area were correlated with upper airway obstruction, and these two variables were independent predictors of OS rate in supraglottic carcinoma patients. CONCLUSIONS: Advanced stage supraglottic carcinoma patients with upper airway obstruction undergoing preoperative tracheotomy experienced worse overall survival. Advanced T stage and greater tumor size were associated with upper airway obstruction, indicating that the negative influence of tumor obstruction on survival may be cause by these two preoperative variables. Therefore, preoperative tracheotomy acts only as an alternative procedure, and is not a prognostic agent.

Vision Transformer-based recognition of diabetic retinopathy grade.

BACKGROUND: In the domain of natural language processing, Transformers are recognized as state-of-the-art models, which opposing to typical convolutional neural networks (CNNs) do not rely on convolution layers. Instead, Transformers employ multi-head attention mechanisms as the main building block to capture long-range contextual relations between image pixels. Recently, CNNs dominated the deep learning solutions for diabetic retinopathy grade recognition. However, spurred by the advantages of Transformers, we propose a Transformer-based method that is appropriate for recognizing the grade of diabetic retinopathy. PURPOSE: The purposes of this work are to demonstrate that (i) the pure attention mechanism is suitable for diabetic retinopathy grade recognition and (ii) Transformers can replace traditional CNNs for diabetic retinopathy grade recognition. METHODS: This paper proposes a Vision Transformer-based method to recognize the grade of diabetic retinopathy. Fundus images are subdivided into non-overlapping patches, which are then converted into sequences by flattening, and undergo a linear and positional embedding process to preserve positional information. Then, the generated sequence is input into several multi-head attention layers to generate the final representation. The first token sequence is input to a softmax classification layer to produce the recognition output in the classification stage. RESULTS: The dataset for training and testing employs fundus images of different resolutions, subdivided into patches. We challenge our method against current CNNs and extreme learning machines and achieve an appealing performance. Specifically, the suggested deep learning architecture attains an accuracy of 91.4%, specificity = 0.977 (95% confidence interval (CI) (0.951-1)), precision = 0.928 (95% CI (0.852-1)), sensitivity = 0.926 (95% CI (0.863-0.989)), quadratic weighted kappa score = 0.935, and area under curve (AUC) = 0.986. CONCLUSION: Our comparative experiments against current methods conclude that our model is competitive and highlight that an attention mechanism based on a Vision Transformer model is promising for the diabetic retinopathy grade recognition task.

Oxygen-Containing Functional Groups Regulating the Carbon/Electrolyte Interfacial Properties Toward Enhanced K+ Storage.

Oxygen-containing functional groups were found to effectively boost the K+ storage performance of carbonaceous materials, however, the mechanism behind the performance enhancement remains unclear. Herein, we report higher rate capability and better long-term cycle performance employing oxygen-doped graphite oxide (GO) as the anode material for potassium ion batteries (PIBs), compared to the raw graphite. The in situ Raman spectroscopy elucidates the adsorption-intercalation hybrid K+ storage mechanism, assigning the capacity enhancement to be mainly correlated with reversible K+ adsorption/desorption at the newly introduced oxygen sites. It is unraveled that the C=O and COOH rather than C-O-C and OH groups contribute to the capacity enhancement. Based on in situ Fourier transform infrared (FT-IR) spectra and in situ electrochemical impedance spectroscopy (EIS), it is found that the oxygen-containing functional groups regulate the components of solid electrolyte interphase (SEI), leading to the formation of highly conductive, intact and robust SEI. Through the systematic investigations, we hereby uncover the K+ storage mechanism of GO-based PIB, and establish a clear relationship between the types/contents of oxygen functional groups and the regulated composition of SEI.

Microstructure-Dependent K+ Storage in Porous Hard Carbon.

Hard carbons (HCs) are emerging as promising anodes for potassium-ion batteries (PIBs) due to overwhelming advantages including cost effectiveness and outstanding physicochemical properties. However, the fundamental K+ storage mechanism in HCs and the key structural parameters that determining K+ storage behaviors remain unclear and require further exploration. Herein, HC materials with controllable micro/mesopore structures are first synthesized by template-assisted spray pyrolysis technology. Detailed experimental analyses including in situ Raman and in situ electrochemical impedance spectroscopy analysis reveal two different K+ storage ways in the porous hard carbon (p-HC), e.g., the adsorption mechanism at high potential region and the intercalation mechanism at low potential region. Both are strongly dependent on the evolution of microstructure and significantly affect the electrochemical performance. Specifically, the adequate micropores act as the active sites for efficient K+ storage and ion-buffering reservoir to relieve the volume expansion, ensuring enhanced specific capacity and good structural stability. The abundant mesopores in the porous structure provide conductive pathways for ion diffusion and/or electrolyte infiltration, endowing fast ionic/electronic transport kinetics. All these together contribute to the high energy density of activated carbon//p-HCs potassium ion hybrid capacitors (74.5 Wh kg-1 , at 184.4 W kg-1 ).

[Construction of green infrastructure network based on spatial priority in downtown of Fuzhou, China.] / åŸºäºŽç©ºé—´ä¼˜å ˆçº§çš„ç¦å·žå¸‚ä¸­å¿ƒåŸŽåŒºç»¿è‰²åŸºç¡€è®¾æ–½ç½‘ç»œæž„å»º.

Given the facts that urban land is extremely limited and ecological environment protection is confronted with severe challenges, it is of great importance to effectively construct green infrastructure (GI) network and identify relatively important landscape ecological components. We identified and prioritized GI network centers in Fuzhou downtown area using the MSPA and the landscape connectivity evaluation. The least cost path method and gravity model were used to construct the potential corridors at multiple levels. The density analysis and blind area analysis were used to extract and prioritize the GI nodes and to obtain the optimized GI network. The results showed that the first-level GI network centers were mainly distributed in the north and south of Fuzhou downtown, while those in the central region were small and scattered. The comprehensive resistance of landscape was low in the periphery but high in the middle, with poor integral connectivity. The GI corridor system with existing corridors and potential corridors was employed to enhance the connectivity among network centers. Furthermore, the GI nodes were extracted to provide a "transfer station" for material circulation and energy flow, which could partly solve the problems including excessive substrate resistance and the long connection corridor in some areas. The spatial prioritization of GI elements could make the construction of GI network more scientific and also provide reference for the future planning period and construction timing of GI network in Fuzhou.

The role of gel wound dressings loaded with stem cells in the treatment of diabetic foot ulcers.

Diabetic foot ulcers (DFUs) are a serious complication of diabetes and the main cause of nontraumatic lower limb amputations, resulting in a serious economic burden on society. The main causes of DFUs include peripheral neuropathy, foot deformity, chronic inflammation, and peripheral artery disease. There are many clinical approaches for the treatment of DFUs, but they are all aimed at addressing a single aetiological factor. Stem cells (SCs), which express many cytokines and a variety of nerve growth factors and modulate immunological function in the wound, may accelerate DFU healing by promoting angiogenesis, cell proliferation, and nerve growth and regulating the inflammatory response. However, the survival time of SCs without scaffold support in the wound is short. Multifunctional gel wound dressings play a critical role in skin wound healing due to their ability to maintain SC survival for a long time, provide moisture and prevent electrolyte and water loss in DFUs. Among the many methods for clinical treatment of DFUs, the most successful one is therapy with gel dressings loaded with SCs. To accelerate DFU healing, gel wound dressings loaded with SCs are needed to promote the survival and migration of SCs and increase wound contraction. This review summarizes the research advancements regarding multifunctional gel wound dressings and SCs in the treatment of DFU to demonstrate the effectiveness and safety of this combinational therapeutic strategy.

Effects of leukemia inhibitory factor receptor on the adipogenic differentiation of human bone marrow mesenchymal stem cells.

Leukemia inhibitory factor (LIF) modulates various biological processes. Although previous studies have described the effects of LIF on adipocyte differentiation, the role of LIF receptor (LIFR) on adipocyte differentiation remains unclear. Using reverse transcription­quantitative PCR (RT­qPCR), LIFR expression was demonstrated to increase during adipogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs), indicating that LIFR may be involved in this process. To further evaluate the association between LIFR and adipogenic differentiation, lentivirus­mediated LIFR knockdown was performed in hMSCs. Cells were divided into two groups: Negative control group and LIFR­knockdown group. During the adipogenic differentiation process, intracellular lipid accumulation was assessed with Oil Red O staining at various time points (days 3, 6 and 9). Additionally, the mRNA and protein expression levels of LIF, LIFR and three molecular indicators of adipogenesis, peroxisome proliferator­activated receptor Î³ (PPARγ), CCAAT enhancer binding protein α (C/EBPα) and fatty acid binding protein 4 (FABP4/aP2), were assessed by RT­qPCR and western blotting. The culture supernatant was collected to evaluate the concentration of LIF using ELISA. The present results suggested that LIFR expression progressively increased during adipogenic differentiation of hMSCs. Conversely, LIFR knockdown significantly suppressed this process. Additionally, PPARγ, C/EBPα and aP2 were inhibited following LIFR knockdown. In contrast with LIFR, the expression levels of LIF were significantly decreased after the initiation of adipogenic differentiation. Therefore, the expression levels of LIF and LIFR exhibited opposite trends. Collectively, the present results suggested that LIFR promoted adipogenic differentiation, whereas LIF may negatively regulate this process.

Nanostructured Metal-Organic Framework (MOF)-Derived Solid Electrolytes Realizing Fast Lithium Ion Transportation Kinetics in Solid-State Batteries.

Solid-state batteries are hindered from practical applications, largely due to the retardant ionic transportation kinetics in solid electrolytes (SEs) and across electrode/electrolyte interfaces. Taking advantage of nanostructured UIO/Li-IL SEs, fast lithium ion transportation is achieved in the bulk and across the electrode/electrolyte interfaces; in UIO/Li-IL SEs, Li-containing ionic liquid (Li-IL) is absorbed in Uio-66 metal-organic frameworks (MOFs). The ionic conductivity of the UIO/Li-IL (15/16) SE reaches 3.2 × 10-4 S cm-1 at 25 °C. Owing to the high surface tension of nanostructured UIO/Li-IL SEs, the contact between electrodes and the SE is excellent; consequently, the interfacial resistances of Li/SE and LiFePO4 /SE at 60 °C are about 44 and 206 Ω cm2 , respectively. Moreover, a stable solid conductive layer is formed at the Li/SE interface, making the Li plating/stripping stable. Solid-state batteries from the UIO/Li-IL SEs show high discharge capacities and excellent retentions (≈130 mA h g-1 with a retention of 100% after 100 cycles at 0.2 C; 119 mA h g-1 with a retention of 94% after 380 cycles at 1 C). This new type of nanostructured UIO/Li-IL SEs is very promising for solid-state batteries, and will open up an avenue toward safe and long lifespan energy storage systems.

Ionic Conduction in Composite Polymer Electrolytes: Case of PEO:Ga-LLZO Composites.

By dispersing Li6.25Ga0.25La3Zr2O12 (Ga-LLZO) nanoparticles in poly(ethylene oxide) (PEO) matrix, PEO:Ga-LLZO composite polymer electrolytes are synthesized. The PEO: Ga-LLZO composite with 16 vol % Ga-LLZO nanoparticles shows a conductivity of 7.2 × 10-5 S cm-1 at 30 °C, about 4 orders of magnitude higher than the conductivity of PEO. The enhancement of the ionic conductivity is closely related to the space charge region (∼3 nm) formed at the interface between the PEO matrix and the Ga-LLZO nanoparticles. The space charge region is observed by transmission electron microscope (TEM) and corroborated by the phase-field simulation. Using the random resistor model, the lithium-ion transport in the composite polymer electrolyte is simulated by the Monte Carlo simulation, demonstrating that the enhanced ionic conductivity can be ascribed to the ionic conduction in the space charge regions and the percolation of the space charge regions.