Stability Enhancement in All-Inorganic Perovskite Light Emitting Diodes via Dual Encapsulation.

Addressing the challenge of lighting stability in perovskite white light emitting diodes (WLEDs) is crucial for their commercial viability. CsPbX3 (X = Cl, Br, I, or mixed) nanocrystals (NCs) are promising for next-generation lighting due to their superior optical and electronic properties. However, the inherent soft material structure of CsPbX3 NCs is particularly susceptible to the elevated temperatures associated with prolonged WLED operation. Additionally, these NCs face stability challenges in high humidity environments, leading to reduced lighting performance. This study introduces a two-step dual encapsulation method, resulting in CsPbBr3@SiO2/Al2SiO5 composite fibers (CFs) with enhanced optical stability under extreme conditions. In testing, WLEDs incorporating these CFs, even under prolonged operation at high power (100 mA for 9 h), maintain consistent electroluminescence (EL) intensity and optoelectronic parameters, with surface temperatures reaching 84.2 °C. Crucially, when subjected to 85 °C and 85% relative humidity for 200 h, the WLEDs preserve 97% of their initial fluorescence efficiency. These findings underscore the efficacy of the dual encapsulation strategy in significantly improving perovskite material stability, marking a significant step toward their commercial application in optoelectronic lighting.

The role of oxygen vacancies in the performance of LiMn2O4 spinel cathodes for lithium-ion batteries.

Oxygen vacancies, known to have unavoidable existence in a spinel LiMn2O4 material, play an essential role in its physicochemical and electrochemical properties. However, the function mechanism of oxygen vacancies and its influence on electrochemical properties have been poorly understood so far. Hence, we investigate the role of oxygen vacancies in the spinel LiMn2O4 material by controlling the annealing atmosphere. The relative amount of oxygen deficiency in the samples prepared under oxygen and air atmospheres is 0.098 and 0.112, respectively. Impressively, the relative oxygen deficiency of the sample increased from 0.112 to 0.196 after re-annealing with nitrogen. However, the conductivity of the material changes from 2.39 to 10.3 mS m-1, but the ion diffusion coefficient is significantly reduced from ∼10-12 to ∼10-13 cm2 s-1, resulting in a decrease in the initial discharge capacity from 136.8 to 85.2 mA h g-1. In addition, we attempted to use the nitrogen-sample annealing again under oxygen, which can significantly reduce the conductivity (from 10.3 to 6.89 mS m-1), and the discharge capacity also increased by 40% of the original. Therefore, the effect of the mechanism of the interaction of the oxygen vacancies on the material electronic conductivity, lithium-ion diffusion coefficient and electrochemical properties provides a basis for the objective treatment of oxygen vacancies in spinel structured materials.

Fabrication of a flexible porous polypyrrole film with a 3D micro-nanostructure and its electrochemical properties.

Flexible energy storage systems have become attractive alternatives for applications in wearable energy storage and sensor devices. This study reports a simple electro-polymerization method for the fabrication of PPy films coated on PPy nanotubes (PPy NTs), which are binding-free, self-standing, and could be used as a flexible electrode for supercapacitors. With optimized kinetics for ion transportation, the mass specific capacitance of the flexible porous PPy films can be elevated to 1.36 F cm-2 at a charging/discharging rate of 2 mA cm-2 (0.45 A g-1). The mass specific capacitance of the flexible porous PPy films reaches 6.5 times as large as that of compact PPy films at a scan rate of 20 mV s-1. Furthermore, due to the large free space for volume change, the capacitance fading of the flexible porous PPy films is less than 3% after 10 000 cycles. This novel design provides an efficient method to synthesize high-performance, flexible and low-cost materials used in supercapacitors.

The effect of various electrolyte cations on electrochemical performance of polypyrrole/RGO based supercapacitors.

In this work, polypyrrole/graphene doped by p-toluenesulfonic is prepared as an active material for supercapacitors, and its capacitance performance is investigated in various aqueous electrolytes including HCl, LiCl, NaCl, and KCl with a concentration of 3 M, respectively. A rising trend of capacitance is observed according to the cationic mobility (Li(+) < Na(+) < K(+) < H(+)), which is due to its effect on the ionic conductivity, efficient ion/charge diffusion/exchange and relaxation time. On the other hand, long-term cycling stability is in the following order: KCl < NaCl < LiCl < HCl, corresponding to the decreasing tendency of cation size (K(+) > Na(+) > Li(+) > H(+)). The reason can be attributed to the fact that the insertion/de-insertion of large size cation brings a significant doping level decrease and an over-oxidation increase during the charging-discharging cycles. Hence, we not only obtain good capacitance performance (280.3 F g(-1) at 5 mV s(-1)), superior rate capability (225.8 F g(-1) at 500 mV s(-1)) and high cycling stability (92.0% capacitance retention after 10,000 cycles at 1 A g(-1)) by employing 3 M HCl as an electrolyte, but also reveal that the electrolyte cations have a significant effect on the supercapacitors' electrochemical performance.

Morphology controllable nano-sheet polypyrrole-graphene composites for high-rate supercapacitor.

Polypyrrole is a promising candidate for supercapacitor electrode materials due to its high capacitance and low cost. However, the major bottlenecks restricting its application are its poor rate capability and cycling stability. Herein, we control the morphology of polypyrrole-graphene composites by adjusting the graphene content, causing the typical "cauliflower" morphology of polypyrrole to gradually turn into the homogeneous nano-sheet morphology of these composites. The composites consequently exhibit good thermal stability, high protonation level (37.4%), high electronic conductivity (625.3 S m(-1)), and fast relaxation time (0.22 s). These remarkable characteristics afford a high capacitance of 255.7 F g(-1) at 0.2 A g(-1), still retaining a capacitance of 199.6 F g(-1) at 25.6 A g(-1). In addition, high capacitance retention of up to 93% is observed after 1000 cycles testing at different current densities of 0.2, 1.6, 6.4, 12.8 and 25.6 A g(-1), indicating high stability. The composite's excellent electrochemical performance is mainly attributed to its nano-sheet structure and high electronic conductivity, providing unobstructed pathways for the fast diffusion and exchange of ions/electrons.

[Effect of catheter-based renal sympathetic denervation in pigs with rapid pacing induced heart failure].

OBJECTIVE: This study investigated the effect of catheter-based renal sympathetic denervation (RDN) in pigs with rapid pacing induced heart failure. METHODS: Heart failure was induced by rapid right ventricular pacing in 12 pigs and pigs were randomly divided into RDN group (n = 6): pacing+RDN at 7 days post pacing; control group (n = 6): pacing only. Echocardiography examination (LVEF, LVEDD and LVESD) was performed before pacing and at 1 and 2 weeks post pacing. Serum biochemical markers including renin, aldosterone and creatinine were also measured at baseline, 1 and 2 weeks after pacing. Repeated renal artery angiography was performed at 1 week after RDN. All pigs were sacrificed to examine the heart and renal pathology and renal artery sympathetic nerve staining at 2 weeks post pacing. RESULTS: LVEF decreased 1 week after rapid pacing from (60.5 ± 6.0)% to (35.3 ± 9.8)%. LVEF was significantly higher [(42.8 ± 5.9) % vs. (33.4 ± 9.7)%, P = 0.001 8] while LVESD was significantly lower [(28.4 ± 3.7) mm vs. (33.0 ± 2.0) mm, P = 0.001 6] in the RDN group than in the control group at 2 weeks post pacing. At 2 weeks after pacing, plasma concentrations of renin and aldosterone were significantly lower in RDN group compared to the control group (all P < 0.05) . Kidney function and blood pressure were comparable between the two groups at 2 weeks post pacing. There were no signs of renal damages such as renal artery stenosis, dissection and thrombus in all pigs after 2 weeks pacing. Sympathetic neurons of adventitia were injured in RND group. CONCLUSION: RDN could significantly improve cardiac function and attenuate left ventricular remodeling via inhibiting renin-angiotensin-aldosterone system in this pacing induced pig heart failure model.

Adapting Crystal Structure and Grain Boundaries through Sm3+ Doping in Na3Zr2Si2PO4 for Boosting Applicability in Sodium Solid-State Batteries.

Solid-state sodium batteries represent a highly promising option for future electrochemical energy storage applications. The ionic conductivity of solid-state electrolytes is one of the significant factors limiting the development of solid-state batteries. In this study, we establish that Sm3+ doping effectively boosts the ionic conductivity of Na3Zr2Si2PO12 (NZSP). The optimal composition, Na3.2Zr1.8Sm0.2Si2-PO12 (NZSP-S20), exhibits a total conductivity of 1.87 mS cm-1 at 23 °C. Structural and microscopic morphology analyses reveal that Sm3+ doping enhances the ionic conductivity of NZSP through structural modulation, phase fraction adjustment, and grain size reduction. High-frequency impedance spectroscopy (40 Hz to 110 MHz) demonstrates that bulk and grain boundaries contribute 49.4 and 50.6%, respectively, to the total conductivity. The structural and microscopic morphology analyses reveal that Sm3+ doping enhances the ionic conductivity of NZSP. Furthermore, the critical current density (CCD) attained in the symmetric cell, assembled by using NZSP-S20 as the solid-state electrolyte and NaSn alloy as the electrode, reaches 2.2 mA cm-1. These results furnish a theoretical foundation for comprehending the modification of solid-state electrolytes.

One-Step Preparation of High-Stability CsPbX3/CsPb2X5 Composite Microplates with Tunable Emission.

The core-shell structure is an effective means to improve the stability and optoelectronic properties of cesium lead halide (CsPbX3 (X = Cl, Br, I)) perovskite quantum dots (QDs). However, confined by the ionic radius differences, developing a core-shell packaging strategy suitable for the entire CsPbX3 system remains a challenge. In this study, we introduce an optimized hot-injection method for the epitaxial growth of the CsPb2X5 substrate on CsPbX3 surfaces, achieved by precisely controlling the reaction time and the ratio of lead halide precursors. The synthesized CsPbX3/CsPb2X5 composite microplates exhibit an emission light spectrum that covers the entire visible range. Crystallographic analyses and density functional theory (DFT) calculations reveal a minimal lattice mismatch between the (002) plane of CsPb2X5 and the (11¯0) plane of CsPbX3, facilitating the formation of high-quality type-I heterojunctions. Furthermore, introducing Cl- and I- significantly alters the surface energy of CsPb2X5's (110) plane, leading to an evolutionary morphological shift of grains from circular to square microplates. Benefiting from the passivation of CsPb2X5, the composites exhibit enhanced optical properties and stability. Subsequently, the white light-emitting diode prepared using the CsPbX3/CsPb2X5 composite microplates has a high luminescence efficiency of 136.76 lm/W and the PL intensity decays by only 3.6% after 24 h of continuous operation.

Embedding cobalt (II, III) oxide nanoparticles into nitrogen-doped carbon nanotubes-grafted hollow polyhedrons as sulfur hosts for ultralong-life lithium-sulfur batteries.

The sluggish reaction kinetics and unfavorable shuttling effect are regarded as obstacles to the practical application of lithium-sulfur (Li-S) batteries. To resolve these inherent drawbacks, we synthesized novel multifunctional Co3O4@NHCP/CNT as the cathode materials consisting of carbon nanotubes (CNTs)-grafted N-doped hollow carbon polyhedrons (NHCP) embedded with cobalt (II, III) oxide (Co3O4) nanoparticles. The results indicate that the NHCP and interconnected CNTs could provide favorable channels for electron/ion transport and physically restrict the diffusion of lithium polysulfides (LiPSs). Furthermore, N doping and in-situ Co3O4 embedding could endow the carbon matrix with strong chemisorption and effective electrocatalytic activity toward LiPSs, thus prominently promoting the sulfur redox reaction. Benefiting from these synergistic effects, the Co3O4@NHCP/CNT electrode exhibits a high initial capacity of 1322.1 mAh/g at 0.1 C, and a capacity retention of 710.4 mAh/g after 500 cycles at 1 C. Impressively, even at a relatively high current density of 4 C, the Co3O4@NHCP/CNT electrode achieves a high capacity of 653.4 mAh/g and outstanding long-term cycle stability for 1000 cycles with a low decay rate of 0.035% per cycle. Hence, the design of N-doped CNTs-grafted hollow carbon polyhedrons coupled with transition metal oxides would provide effective promising perspective for developing high-performance Li-S batteries.

Thin Li1.3Al0.3Ti1.7(PO4)3-based composite solid electrolyte with a reinforced interface of in situ formed poly(1,3-dioxolane) for lithium metal batteries.

Composite solid electrolytes (CSEs) exhibit great potential due to their advantages of both sufficient strength and high ionic conductivity. However, their interfacial impendence and thickness hinder potential applications. Herein, a thin CSE with good interface performance is designed through the combination of immersion precipitation and in situ polymerization. By employing a nonsolvent in immersion precipitation, a porous poly(vinylidene fluoride-cohexafluoropropylene) (PVDF-HFP) membrane could be rapidly created. The pores in the membrane could accommodate sufficient well-dispersed inorganic Li1.3Al0.3Ti1.7(PO4)3 (LATP) particles. Subsequent in situ polymerized 1,3­dioxolane (PDOL) further protects LATP from reacting with lithium metal and supplies superior interfacial performance. The CSE has a thickness of âˆ¼ 60 µm, ionic conductivity of 1.57 × 10-4 S cm-1, and oxidation stability of 5.3 V. The Li/1.25LATP-CSE/Li symmetric cell has a long cycling performance of 780 h at 0.3 mA cm-2 for 0.3 mAh cm-2. The Li/1.25LATP-CSE/LiFePO4 cell exhibits a discharge capacity of 144.6 mAh/g at 1C and a capacity retention of 97.72 % after 300 cycles. Continuous depletion of lithium salts due to the reconstruction of the solid electrolyte interface (SEI) may be responsible for battery failure. The combination of the fabrication method and failure mechanism gives new insight into designing CSEs.

In Situ Fabrication of Lead-Free Double Perovskite/Polymer Composite Films for Optoelectronic Devices and Anticounterfeit Printing.

Lead-free double perovskites (DP) have the potential to become a rising star in the next generation of lighting markets by addressing the toxicity and instability issues associated with traditional lead-based perovskites. However, high concentrations of hydrochloric acid (HCl) were often employed as a solvent in the preparation of most DPs, accompanied by slow crystallization at high temperatures, which not only raised the risk and cost in the preparation process, but also had a potential threat to the environment. Here, an in situ fabrication strategy was proposed to realize the crystallization of DP in the polymer at low temperature with a mild dimethyl sulfoxide (DMSO) solvent, and subsequently obtained optically well-behaved Cs2Na0.8Ag0.2BiCl6/PMMA composite films (CFs) by doping with Ag+, generating bright orange luminescence with a photoluminescence quantum yield (PLQY) of up to 21.52%. Moreover, the growth dynamics of Cs2Na0.8Ag0.2BiCl6/PMMA CFs was further investigated by in situ optical transformation, which was extended to other DP-based polymer CFs. Finally, these CFs exhibited excellent performance in optoelectronic devices and anticounterfeit printing, the results of which provide a new pathway to advance the development of lead-free DP materials in the optical field.

Improvement of stability and capacity of Co-free, Li-rich layered oxide Li1.2Ni0.2Mn0.6O2 cathode material through defect control.

Layered oxides based on manganese (Mn), rich in lithium (Li), and free of cobalt (Co) are the most promising cathode candidates used for lithium-ion batteries due to their high capacity, high voltage and low cost. These types of material can be written as xLi2MnO3·(1 - x) LiTMO2 (TM = Ni,Mn,etc.). Though, Li2MnO3 is known to have poor cycling stability and low capacity, which hinder its industrial application commercially. In this work, Li1.2Ni0.2Mn0.6O2 materials with different amounts of structural defects was successfully synthesized using powder metallurgy followed by different cooling processes in order to improve its electrochemical properties. Microstructural analyses and electrochemical measurements were carried out on the study samples synthesized by a combination of X-ray diffraction, transmission electron microscopy, and cyclic voltammetry. It is found that the disorder of the transition metal layer in Li2MnO3 promotes its electrochemical activity, whereas the Li/Ni antisites of the Li layer maintain the stability of its local structure. The material with optimal amount of structural defects had an initial capacity of 188.2 mAh g-1, while maintaining an excellent specific capacity of 144.2 mAh g-1 after 500 cycles at 1C. In comparison, Li1.2Ni0.2Mn0.6O2 without structural defect only gives a capacity of 40.8 mAh g-1 after cycling. This microstructural control strategy provides a simple and effective route to develop high-performance Co-free, Li-rich Mn-based cathode materials and scale-up manufacturing.

Studies on the optical stability of CsPbBr3 with different dimensions (0D, 1D, 2D, 3D) under thermal environments.

The thermal stability of phosphor materials had long been a bottleneck in their commercialization. Nowadays, cesium lead halide perovskite CsPbBr3 has been considered a potential replacement for the next generation of optoelectronic devices due to its excellent optical and electronic properties, however, the devices inevitably generate high temperatures on the surface under prolonged energization conditions in practical applications, which can be fatal to CsPbBr3. Despite the various strategies that have been employed to improve the thermal stability of CsPbBr3, systematic studies of the thermal stability of the basis CsPbBr3 are lacking. In this study, CsPbBr3 with different dimensions (0D quantum dots (QDs), 1D nanowires (NWs), 2D nanoplate (NPs), 3D micron crystals (MCs)) was prepared by traditional high-temperature thermal injection, and a systematic study was carried out on their optical properties and thermal stability. The results revealed that the dimensional change will directly influence the optical properties as well as the thermal stability of CsPbBr3. In particular, 3D CsPbBr3 MCs maintained relatively high thermal stability under high-temperature environments, which will bring interest for the commercialization of next-generation perovskite optoelectronic devices.

Ultrastable CsPbBr3@CsPb2Br5@TiO2 Composites for Photocatalytic and White Light-Emitting Diodes.

Although cesium halide lead (CsPbX3, X = Cl, Br, I) perovskite quantum dots (QDs) have excellent photovoltaic properties, their unstable characteristics are major limitations to application. Previous research has demonstrated that the core-shell structure can significantly improve the stability of CsPbX3 QDs and form heterojunctions at interfaces, enabling multifunctionalization of perovskite materials. In this article, we propose a convenient method to construct core-shell-structured perovskite materials, in which CsPbBr3@CsPb2Br5 core-shell micrometer crystals can be prepared by controlling the ratio of Cs+/Pb2+ in the precursor and the reaction time. The materials exhibited enhanced optical properties and stability that provided for further postprocessing. Subsequently, CsPbBr3@CsPb2Br5@TiO2 composites were obtained by coating a layer of dense TiO2 nanoparticles on the surfaces of micrometer crystals through hydrolysis of titanium precursors. According to density functional theory (DFT) calculations and experimental results, the presence of surface TiO2 promoted delocalization of photogenerated electrons and holes, enabling the CsPbBr3@CsPb2Br5@TiO2 composites to exhibit excellent performance in the field of photocatalysis. In addition, due to passivation of surface defects by CsPb2Br5 and TiO2 shells, the luminous intensity of white light-emitting diodes prepared with the materials only decayed by 2%-3% at high temperatures (>100 °C) when working for 24 h.

Preparation of CsPb(Cl/Br)3/TiO2:Eu3+ composites for white light emitting diodes.

The inherent single narrow emission peak and fast anion exchange process of cesium lead halide perovskite CsPbX3 (X = Cl, Br, I) nanocrystals severely limited its application in white light-emitting diodes. Previous studies have shown that composite structures can passivate surface defects of NCs and improve the stability of perovskite materials, but complex post-treatment processes commonly lead to dissolution of NCs. In this study, CsPb(Cl/Br)3 NCs was in-situ grown in TiO2 hollow shells doped with Eu3+ ions by a modified thermal injection method to prepare CsPb(Cl/Br)3/TiO2:Eu3+ composites with direct excitation of white light without additional treatment. Among them, the well-crystalline TiO2 shells acted as both a substrate for the dopant, avoiding the direct doping of Eu3+ into the interior of NCs to affect the crystal structure of the perovskite materials, and also as a protection layer to isolate the contact between PL quenching molecules and NCs, which significantly improves the stability. Further, the WLED prepared using the composites had bright white light emission, luminous efficiency of 87.39 lm/W, and long-time operating stability, which provided new options for the development of perovskite devices.

Effects of renal denervation on cardiac function after percutaneous coronary intervention in patients with acute myocardial infarction.

Objective: To observe the effect of renal artery denervation (RDN) on cardiac function in patients with acute myocardial infarction after percutaneous coronary intervention (AMI-PCI). Methods: This is a single-centre, prospective randomized controlled study. A total of 108 AMI-PCI patients were randomly assigned to the RDN group or the control group at 1:1 ratio. All patients received standardized drug therapy after PCI, and patients in the RDN group underwent additional RDN at 4 weeks after the PCI. The follow-up period was 6 months after RDN. Echocardiography-derived parameters, cardiopulmonary exercise testing (CPET) data, Holter electrocardiogram, heart rate variability (HRV) at baseline and at the 6 months-follow up were analyzed. Results: Baseline indexes were similar between the two groups (all P > 0.05). After 6 months of follow-up, the echocardiography-derived left ventricular ejection fraction was significantly higher in the RDN group than those in the control group. Cardiopulmonary exercise test indicators VO2Max, metabolic equivalents were significantly higher in the RDN group than in the control group. HRV analysis showed that standard deviation of the normal-to-normal R-R intervals, levels of square root of the mean squared difference of successive RR intervals were significantly higher in the RDN group than those in the control group. Conclusions: RDN intervention after PCI in AMI patients is associated with improved cardiac function, improved exercise tolerance in AMI patients post PCI. The underlying mechanism of RDN induced beneficial effects may be related to the inhibition of sympathetic nerve activity and restoration of the sympathetic-vagal balance in these patients.

Efficient Anion Fluoride-Doping Strategy to Enhance the Performance in Garnet-Type Solid Electrolyte Li7La3Zr2O12.

Garnet-type solid-state electrolyte Li7La3Zr2O12 (LLZO) is expected to realize the next generation of high-energy-density lithium-ion batteries. However, the severe dendrite penetration at the pores and grain boundaries inside the solid electrolyte hinders the practical application of LLZO. Here, it is reported that the desirable quality and dense garnet Li6.8Al0.2La3Zr2O11.80F0.20 can be obtained by fluoride anion doping, which can effectively facilitate grain nucleation and refine the grain; thereby, the ionic conductivity increased to 7.45 × 10-4 at 30 °C and the relative density reached to 95.4%. At the same time, we introduced a transition layer to build the Li6.8Al0.2La3Zr2O11.80F0.20-t electrolyte in order to supply a stable contact; as a result, the interface resistance of Li|Li6.8Al0.2La3Zr2O11.80F0.20-t decreases to 12.8 Ω cm2. The Li|Li6.8Al0.2La3Zr2O11.80F0.20-t|Li symmetric cell achieved a critical current density of 1.0 mA cm-2 at 25 °C, which could run stably for 1000 h without a short circuit at 0.3 mA cm-2 and 25 °C. Moreover, the Li|LiFePO4 battery exhibited a high Coulombic efficiency (>99.5%), an excellent rate capability, and a great capacity retention (123.7 mA h g-1, ≈80%) over 500 cycles at 0.3C and 25 °C. The Li|LiNi0.8Co0.1Mn0.1O2 cell operated well at 0.2C and 25 °C and delivered a high initial discharge capacity of 151.4 mA h g-1 with a good capacity retention (70%) after 195 cycles. This work demonstrates that the anion doping in LLZO is an effective method to prepare a dense garnet ceramic for the high-performance lithium batteries.

Effects of renal denervation therapy on cardiac function and malignant arrhythmia in patients with reduced left ventricular ejection fraction and narrow QRS complexes treated with implantable cardioverter defibrillator.

Objective : The purpose of this study was to explore the effects of renal denervation (RDN) on cardiac function and malignant arrhythmia in patients with reduced left ventricular ejection fraction (HFrEF) and narrow QRS treated with an implantable cardioverter defibrillator (ICD). Methods: A total of 20 eligible HFrEF patients [left ventricular ejection fraction (LVEF) <40%] and narrow QRS complexes (QRS duration <120 ms) were randomized into either the ICD plus RDN group or the ICD only group during 17 April 2014 to 22 November 2016. Clinical data, including clinical characteristics, blood biochemistry, B-type natriuretic peptide, echocardiographic indexes, 6-min walk distance (6MWD), New York Heart Association (NYHA) classification, and count of ICD discharge events before and after the operation were analyzed. Patients were followed up for up to 3 years post ICD or ICD plus RDN. Results: Baseline clinical data were comparable between the two groups. Higher LVEF (%) (mixed model repeated measure, p = 0.0306) (39.50% ± 9.63% vs. 31.20% ± 4.52% at 1 year; 41.57% ± 9.62% vs. 31.40% ± 8.14% at 3 years), systolic blood pressure (p = 0.0356), and longer 6MWD (p < 0.0001) as well as reduction of NYHA classification (p < 0.0001) were evidenced in the ICD plus RDN group compared to ICD only group during follow-up. Patients in the ICD plus RDN group experienced fewer ICD discharge events (2 vs. 40) and decreased diuretic use; rehospitalization rate (30% vs. 100%, p = 0.0031) and cardiogenic mortality rate (0% vs. 50%, p = 0.0325) were also significantly lower in the ICD plus RDN group than in the ICD only group during follow-up. Conclusion: ICD implantation plus RDN could significantly improve cardiac function and cardiac outcome as well as increase exercise capacity compared to ICD only for HFrEF patients with narrow QRS complexes.

Facile strategy of hollow polyaniline nanotubes supported on Ti3C2-MXene nanosheets for High-performance symmetric supercapacitors.

Titanium carbide MXene (Ti3C2) has attracted significant research interest because of its extraordinary advantages as advanced electrode material for energy storage. In this work, we explored a facile strategy to construct Ti3C2-based hierarchical composite materials by surface modification using pseudocapacitive materials. The method involved the synthesis of the exfoliation of ultrathin Ti3C2 nanosheets, followed by one-pot in situ polymerization and surface decoration using polyaniline nanotubes (PANI-NTs). Herein, the self-aggregation of Ti3C2 layers had been effectively suppressed, resulting in an enhanced interlamellar spacing and enlarged ion contact area. Furthermore, the novel hierarchical structure of Ti3C2/PANI-NTs can facilitate the electrolyte ions diffusion, which also boosted more electrochemical active sites to become more accessible. In addition, the electrochemical test in the three-electrode system demonstrated that the specific capacitance of the Ti3C2/PANI-NTs-1 composite can be as high as 596.6F g-1 at 0.1 A g-1, remaining 94.7% retention of initial capacitance after 5000 cycles of charge/discharge. Moreover, the symmetric supercapacitor device based on Ti3C2/PANI-NTs-1 composite exhibited a maximum energy density of 25.6 Wh kg-1 (at 153.2 W kg-1) and an impressive power density of 1610.8 W kg-1 (at 13.2 Wh kg-1), as well as outstanding cycling stability (81.1% retention of the capacitance after 4000 cycles). These electrochemical measurements indicated that the performance of Ti3C2-based supercapacitors could be immensely improved by designing and constructing the hierarchical structure with abundant pseudocapacitive materials. Furthermore, this strategy could be extended to other MXenes composite materials as advanced electrodes by taking full advantage of their potentials for new symmetric supercapacitors.

Double Donors Tuning Conductivity of LiVPO4F for Advanced Lithium-Ion Batteries.

To fulfill the increasing demand of lithium-ion batteries for realizing high energy density and great cycling stability under high rate, the cathode material capable of efficient electron and Li+-ion transportation is necessarily demanded. Herein, we propose a double-donor doping strategy by taking the carbon-coated LiVPO4F as a model system. The Hall effect confirms that either or both Mg2+ substitution of Li+ and Nb5+ substitution of V3+ cause the carrier-type transformation from p-type to n-type. The great enhancements of electronic conductivity and ionic conductivity are realized in Li0.995Mg0.005V0.98Nb0.02PO4F, which also exhibits a markedly improved Li+ diffusion coefficient and reduced electrochemical polarization. The carbon-coating layer can effectively prevent the decomposition reaction of electrolyte, allowing for good structural stability of Li0.995Mg0.005V0.98Nb0.02PO4F when suffering fast Li+ insertion/extraction. As expected, the Li0.995Mg0.005V0.98Nb0.02PO4F cathode exhibited superior electrochemical properties with an initial discharge capacity of 124.5 mA h g-1 and capacity retention of 97.3% after 600 cycles at 1.6C. Even under a high rate of 8C, the discharge energy density was 392 Wh kg-1 at the beginning and showed a retention rate of 84.4% after 2000 cycles.