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Covalent organic frameworks (COFs) have emerged as promising renewable electrode materials for LIBs and gained significant attention, but their capacity has been limited by the densely packed 2D layer structures, low active site availability, and poor electronic conductivity. Combining COFs with high-conductivity MXenes is an effective strategy to enhance their electrochemical performance. Nevertheless, simply gluing them without conformal growth and covalent linkage restricts the number of redox-active sites and the structural stability of the composite. Therefore, in this study, a covalently assembled 3D COF on Ti3C2 MXenes (Ti3C2@COF) is synthesized and serves as an ultralong cycling electrode material for LIBs. Due to the covalent bonding between the COF and Ti3C2, the Ti3C2@COF composite exhibits excellent stability, good conductivity, and a unique 3D cavity structure that enables stable Li+ storage and rapid ion transport. As a result, the Ti3C2-supported 3D COF nanosheets deliver a high specific capacity of 490 mAh g−1 at 0.1 A g−1, along with an ultralong cyclability of 10,000 cycles at 1 A g−1. This work may inspire a wide range of 3D COF designs for high-performance electrode materials. [ABSTRACT FROM AUTHOR]

Rechargeable metal‐ion batteries (MIBs) beyond lithium‐ion batteries based on Na, K, Mg, and Al metal electrodes which are earth‐abundant and low‐cost have been developed for large‐scale energy storage systems. MXenes, a type of transition metal carbides, nitrides, and carbonitrides, are discovered as electrodes for MIBs owing to their distinctive properties of large‐scale ultrathin conductive 2D structures, adjustable surface functional groups, regulable interlayer spacing, and high specific surface area. Herein, the properties of MXenes are summarized and the recent progress on MXene‐based materials for diversified MIBs (Li, Na, K, Mg, and Al‐ion batteries) is introduced. The main focus is on the synthesis and applications of MXene‐based materials in MIBs, and their roles in electrochemical reactions. Further examples are provided to demonstrate the significant function of MXene‐based composite as active materials, substrates, collectors, and precursors in different MIBs, highlighting the enormous potential of MXene‐based materials to construct advanced electrodes. This review expects to offer a deep understanding of the relationship between the electrochemical performance and the MXene‐based electrodes, which will promote more novel and creative breakthroughs in the MXenes‐based electrodes for MIBs. [ABSTRACT FROM AUTHOR]

While sulfide solid electrolytes such as Na11Sn2PS12 can allow fast transport of Na+ ions, their utilization in solid sodium ion batteries is rather unsuccessful since they are not electrochemically compatible to both high‐voltage cathodes and sodium metal anode. In this work, we devise an effective approach toward realizing solid sodium ion batteries, using the Na11Sn2PS12 electrolyte and slurry‐coated NASICON‐type Na3MnTi(PO4)3@C as high‐voltage cathode, highly beneficial for low processing cost and high content/loading of active cathode matter. We report that through significantly improved integrity of electrolyte‐cathode interface, such solid sodium ion batteries can deliver outstanding cycling and rate performance, with a charge voltage resilience up to 4.1 V, a high cathode discharge capacity of 128.7 mAh g−1 against the Na3MnTi(PO4)3@C in cathode is achieved at 0.05 C, and capacity retention ratio of 82% with a rate of 0.1 C is realized after prolonged cycling at room temperature. Besides, we demonstrate that such a solid sodium ion battery can even perform at a sub‐zero Celsius temperature of −10°C, when the conventional control cell using liquid electrolyte completely fail to function. This work is to offer a dependable avenue in engineering next generation of safe solid ion batteries based on highly sustainable and much cheaper material resources. [ABSTRACT FROM AUTHOR]

Lead‐free Cs2AgBiBr6 double perovskite has received widespread attention because of its non‐toxicity and high thermal stability. However, intrinsic bromide ion (Br–) migration limits continuous operation of Cs2AgBiBr6‐based perovskite solar cells (PSCs). Herein, an operational and simple strategy is carried out to improve the power conversion efficiency (PCE) and long‐term stability of Cs2AgBiBr6‐based PSCs by introducing 1‐butyl‐1‐methylpyrrolidinium chloride (BMPyrCl) and 1‐butyl‐3‐methylpyridinium chloride (BMPyCl) ionic liquids (ILs). The higher binding energy between Br– in Cs2AgBiBr6 and cation in IL containing pyrrole can inhibit Br– migration effectively, thereby reducing film defects and improving energy level matching. The optimized PCE of 2.22% is obtained for hole transport layer‐free, carbon‐based PSC, which hardly degrades at 40% ± 5% relative humidity and 25 °C for 40 days. This work highlights an effective method to mitigate the halide migration in Cs2AgBiBr6 perovskite, thus providing an effective route in promoting the development of lead‐free double PSCs. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries have been regarded as a promising next‐generation energy storage technology for their ultrahigh theoretical energy density compared with those of the traditional lithium‐ion batteries. However, the practical applications of Li–S batteries are still blocked by notorious problems such as the shuttle effect and the uncontrollable growth of lithium dendrites. Recently, the rapid development of electrospinning technology provides reliable methods in preparing flexible nanofibers materials and is widely applied to Li–S batteries serving as hosts, interlayers, and separators, which are considered as a promising strategy to achieve high energy density flexible Li–S batteries. In this review, a fundamental introduction of electrospinning technology and multifarious electrospinning‐based nanofibers used in flexible Li–S batteries are presented. More importantly, crucial parameters of specific capacity, electrolyte/sulfur (E/S) ratio, sulfur loading, and cathode tap density are emphasized based on the proposed mathematic model, in which the electrospinning‐based nanofibers are used as important components in Li–S batteries to achieve high gravimetric (WG) and volume (WV) energy density of 500 Wh kg−1 and 700 Wh L−1, respectively. These systematic summaries not only provide the principles in nanofiber‐based electrode design but also propose enlightening directions for the commercialized Li–S batteries with high WG and WV. [ABSTRACT FROM AUTHOR]

Heteroatom doped graphene materials are considered as promising anode for high‐performance sodium‐ion batteries (SIBs). Defective and porous structure especially with large specific surface area is generally considered as a feasible strategy to boost reaction kinetics; however, the unwanted side reaction at the anode hinders the practical application of SIBs. In this work, a precisely controlled Al2O3 coated nitrogen doped vertical graphene nanosheets (NVG) anode material has been proposed, which exhibits excellent sodium storage capacity and cycling stability. The ultrathin Al2O3 coating on the NVG is considered to help construct an advantageous interface between electrode and electrolyte, both alleviating the electrolyte decomposition and enhancing sodium adsorption ability. As a result, the optimal Al2O3 coated NVG materials delivers a high reversible capacity (835.0 mAh g−1) and superior cycling stability (retention of 92.3% after 5000 cycles). This work demonstrates a new way to design graphene‐based anode materials for high‐performance sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

All‐inorganic CsPbBr3‐based perovskite solar cells (PSCs) have attracted great attention because of their high chemical and thermal stabilities in ambient air. However, the short‐circuit current density (Jsc) of CsPbBr3‐based PSCs is inadequate under solar illumination because of the wide bandgap, inefficient charge extraction and recombination loss, leading to lower power‐conversion efficiencies (PCEs). It is envisaged that in addition to narrowing the bandgap by alloying, Jsc of the PSCs could be enhanced by effective improvement of electron transportation, suppression of charge recombination at the interface between the perovskite and electron transporting layer (ETL), and tuning of the space charge field in the device. In this work, Nb‐doped SnO2 films as ETLs in the CsPbBr3‐based PSCs have been deposited at room temperature by high target utilization sputtering (HiTUS). Through optimizing the Nb doping level alone, the Jsc was increased by nearly 19%, from 7.51 to 8.92 mA·cm−2 and the PCE was enhanced by 27% from 6.73% to 8.54%. The overall benefit by replacing the spin‐coated SnO2 with sputtered SnO2 with Nb doping was up to 39% increase in Jsc and 62% increase in PCE. Moreover, the PCE of the optimized device showed negligible degradation over exposure to ambient environment (T ˜ 25 °C, RH˜45%), with 95.4% of the original PCE being maintained after storing the device for 1200 h. [ABSTRACT FROM AUTHOR]

The realistic application of lithium–sulfur (Li–S) batteries has been severely hindered by the sluggish conversion kinetics of polysulfides (LiPS) and inhomogeneous deposition of Li2S at high sulfur loading and low electrolyte/sulfur ratio (E/S). Herein, a flexible Li–S battery architecture based on electrocatalyzed cathodes made of interfacial engineered TiC nanofibers and in situ grown vertical graphene are developed. Integrated 1D/2D heterostructured electrocatalysts are realized to enable highly improved Li+ and electron transportation together with significantly enhanced affinity to LiPS, which effectively accelerate the conversion kinetics between sulfur species, and thus induce homogeneous deposition of Li2S in the catalyzed cathodes. Consequently, highly active electro‐electrocatalysts‐based cells exhibit remarkable rate capability at 2C with a high specific capacity of 971 mAh g−1. Even at ultra‐high sulfur loading and low E/S ratio, the battery still delivers a high areal capacity of 9.1 mAh cm−2, with a flexible pouch cell being demonstrated to power a LED array at different bending angles with a high capacity over 100 cycles. This work puts forward a novel pathway for the rational design of effective nanofiber electrocatalysts for cathodes of high‐performance Li–S batteries. [ABSTRACT FROM AUTHOR]

The practical exploitation of lithium–sulfur batteries is hindered by a multitude of obstacles, including sluggish redox kinetics and the shuttling of soluble lithium polysulfide (LiPS) during long-term cycling. Here, we report the construction of a continuous three-dimensional conductive carbon nanofiber supported TiO2–MXene heterojunction framework (TM-CNFs) via a one-step electrospinning–carbonization strategy, with MXene as the "energy band bridge" between the carbon substrate and TiO2 to reduce the barrier for electron transfer. Theoretical simulations and experimental tests clearly indicate that the TiO2–MXene heterojunction can accelerate the mass transfer process of LiPS at the interface. Meanwhile, the redistribution of electrons at the heterojunction interfaces accelerates the surface electron reversible exchange. Based on the enhanced conductivity, the strong chemisorption for LiPS, and the remarkable catalysis for the simultaneous conversion of the sulfur species, Li–S cells with a flexible TM-CNFs host demonstrate excellent rate performance and cycling stability (807.3 mA h g−1 at 0.5C after 200 cycles, and 723.3 mA h g−1 at 1C after 500 cycles), a high areal capacity and energy density (10.85 mA h cm−2 and 1909.86 W h kg−1 at a high sulfur area loading of 10.5 mg cm−2), and a high gravimetric full-cell energy density over 300 W h kg−1. The present work provides a novel perspective on the design of electrocatalysts for LiPS redox and a feasible strategy to improve the electrochemical performance of practical lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

Objective: To study the activity of vitamin K-dependent gamma-glutamyl carboxylase in patients with calcium oxalate (CaOx) urolithiasis compared with healthy individuals and to assess its relationship to the renal calcium oxalate urolithiasis., Methods: Renal parenchymas were harvested from urolithic patients and renal tumor patients undergoing nephrectomy. The renal carboxylase activity was evaluated as the radioactivity of [(14)C] labeled sodium bicarbonate in carboxylic reactions in vitro using beta-liquid scintillation counting., Results: Significantly reduced activity of renal vitamin K-dependent gamma-glutamyl carboxylase was observed in the urolithic group as compared with normal controls (P < 0.01)., Conclusion: It suggests that the reduced carboxylase activity observed in the urolithic patients may play an important role in the course of renal calcium oxalate urolithiasis.