Search

This paper presents an efficient cascade calibration method with an improved Levenberg–Marquardt and sine–cosine hybrid algorithm to enhance the absolute positioning accuracy of robotic grinding systems. To expedite convergence in the Levenberg–Marquardt algorithm, a dynamic adaptive weight mechanism is introduced, enhancing global and local search capabilities. Furthermore, a novel learning rate, combining exponential and cosine functions, addresses local optima in the algorithm. The improved Levenberg–Marquardt algorithm is employed to obtain suboptimal values for robot kinematic parameter deviations. Subsequently, these values are used as central points for generating a candidate solution set in the sine–cosine algorithm, resulting in more accurate kinematic parameter deviation identification. This innovative dual-search optimization approach combines the two algorithms. Experimental results confirm the substantial improvements in absolute positioning accuracy and surface machining precision achieved by the proposed model, with the calibration method's effectiveness verified through experimentation. [ABSTRACT FROM AUTHOR]

The precision of workpiece machining is critically influenced by the geometric errors in the kinematics of grind robots, which directly affect their absolute positioning accuracy. To tackle this challenge, this paper introduces a logistic-tent chaotic mapping Levenberg Marquardt algorithm designed to accurately identify and compensate for this geometric error. the approach begins with the construction of a forward kinematic model and an error model specific to the robot. Then the algorithm is adopted to identify and compensate for the geometric error. The method establishes a mapping interval around the initial candidate solutions derived from iterative applications of the Levenberg Marquardt algorithm. Within this interval, the logistic-tent chaotic mapping method generates a diverse set of candidate solutions. These candidates are evaluated based on their fitness values, with the optimal solution selected for subsequent iterations. Empirical compensation experiments have validated the proposed method's precision and effectiveness, demonstrating a 6% increase in compensation accuracy and a 47.68% improvement in efficiency compared to existing state-of-the-art approaches. This process not only minimizes the truncation error inherent in the Levenberg Marquardt algorithm but also significantly enhances solution efficiency. Moreover, simulation experiments on grind processes further validate the method's ability to significantly improve the quality of workpiece machining. [ABSTRACT FROM AUTHOR]

Electrolytes with high stability against both Li anode and high‐voltage cathode are critical for high‐energy and long‐cycling lithium metal batteries (LMBs). However, the free active solvents in common electrolytes are susceptible to decomposition at both Li anode and high‐voltage cathode. Although recently developed locally high‐concentration electrolytes (LHCEs) have largely restricted active solvents via Li+ coordination, the free molecules are still released upon the desolvation of Li+ at the surface of electrodes, causing continuous decomposition during long‐cycling processes. Here, a molecule competitive solvation electrolyte (MCE) is shown to stabilize high‐voltage LMBs by introducing a well‐designed and newly synthetic bipolar solvent molecule with one ion‐dissociative polar head and the other highly fluorinated nonpolar tail. The bipolar molecules competitively dissociate Li+ via weak coordination interactions, drastically reducing the ratio of active solvents in electrolytes and the detrimental decomposition at electrodes during the desolvation processes. Consequently, the MCE enables a 1.4‐Ah Li metal pouch cell with a stack energy density of 450 Wh kg−1 along with exceptional operation stability over 400 cycles (retention: 81%). Furthermore, the MCE also maintains the stable operation of a 2.5‐Ah Li‐S pouch cell with an excellent energy density of 417 Wh kg−1 for 70 cycles under practical conditions. [ABSTRACT FROM AUTHOR]

Achieving high-precision manufacturing of optical components requires improving the absolute positioning accuracy of the robot to the highest possible level. Identifying the robot's kinematic parameters and compensating for kinematic errors are effective methods for improving the robot's positioning accuracy. This paper proposes a hybrid algorithm that combines the Levenberg–Marquardt algorithm and an opposition-based learning squirrel search algorithm to identify the kinematic parameters of a polishing robot. Firstly, the Levenberg–Marquardt algorithm is utilized to solve the suboptimal values of kinematic parameter deviations. Secondly, an opposition-based learning strategy is integrated into the standard squirrel search algorithm to increase the diversity of the population and prevent the population from getting stuck in local optima. The suboptimal values obtained by the Levenberg–Marquardt algorithm are subsequently used as the central values to generate the initial population for the opposition-based learning squirrel search algorithm, which helps identify more accurate kinematic parameter deviations. Ultimately, the kinematic parameters of the robot are effectively calibration. The calibration experimental results showed that the proposed method achieved a high level of calibration accuracy, resulting in a 62.61% improvement in absolute positioning error compared to before calibration. Offline machining experiments have validated the effectiveness of LM-OBLSSA in reducing deviations in the dwell points of optical components during the machining process. [ABSTRACT FROM AUTHOR]

Monodisperse gold nanoparticles (AuNPs) are an important guarantee of their scientific value and technical reproducibility in applications. The tartrate has a similar molecule structure and physicochemical properties to citrate, bur is much less reducibility and is usually not favorable for the formation of monodisperse AuNPs. We have prepared monodisperse AuNPs with tartrate (potassium sodium tartrate) as reducing and capping agent. Various parameters affecting the monodisperse properties during the preparation of tartrate‐capped AuNPs were analyzed, such as reversing the order of reactant addition and ripening of seeds, while adjusting the synthesis parameters such as time, temperature, and pH value. The final results show that the addition of a trace amount of silver (Ag) ion into chloroauric acid, the monodispersed tartrate‐capped AuNPs can be obtained with the size range of 9–40 nm. The fabricated gold seeds and grown tartrate‐capped AuNPs have narrow size dispersions (or polydispersity, σ<10 %). The minimum size dispersion of AuNPs with twice growth steps was as low as 5.73 %. So, the weak reducing agent of tartrate is one of good candidates to synthesize the monodispersity of AuNPs. Additionally, tartrate‐capped AuNPs have good stability and can be easily modified and form a large two‐dimensional (2D) monolayer nanostructure film. [ABSTRACT FROM AUTHOR]

Advancements in astronomical telescopes and cutting-edge technologies, including deep ultraviolet (DUV) and extreme ultraviolet (EUV) lithography, have escalated demands and imposed stringent surface quality requirements on optical system components. Achieving near-ideal optical components requires ultra-smooth surfaces with sub-nanometer roughness, no sub-surface damage, minimal surface defects, low residual stresses, and intact lattice integrity. This necessity has driven the rapid development and diversification of ultra-smooth surface fabrication technologies. This paper summarizes recent advances in ultra-smooth surface processing technologies, categorized by their material removal mechanisms. A subsequent comparative analysis evaluates the roughness and polishing characteristics of ultra-smooth surfaces processed on various materials, including fused silica, monocrystalline silicon, silicon carbide, and sapphire. To maximize each process's advantages and achieve higher-quality surfaces, the paper discusses tailored processing methods and iterations for different materials. Finally, the paper anticipates future development trends in response to current challenges in ultra-smooth surface processing technology, providing a systematic reference for the study of the production of large-sized freeform surfaces. [ABSTRACT FROM AUTHOR]

Flexible ultrathin copper films are desired for use as flexible electromagnetic shielding, smart clothing, and energy storage devices. The fabrication of such films can be realized through plasma assisted surface coating on flexible polymer thin films. Unfortunately, the use of plasma treatment leads to substantial damage to the polymer substrates, which is particularly serious for ultrathin films. Here, we report the fabrication of stretchable, ultrathin, yet ultrastrong hybrid copper films via simple nanoconfinement. The hybrid films are prepared by the conformal electroless deposition of copper nanoparticles on nanofibrils of ultrastrong ultrahigh molecular weight polyethylene (UHMWPE) membranes. These flyweight hybrid copper films (0.3 mg cm−2) possess a high mechanical strength of 390 MPa, 26% larger than pure copper foils; a low resistivity of 5 × 10−8 Ω m at a cyclic extensional strain of 1%; and macroscopic shape recovery after applying a biaxial extension strain of 10%. The shape recoverability and the high mechanical strength of the hybrid copper film were derived from the unique nanofibrous network of the ultrastrong UHMWPE substrate. As an application, we fabricated a lithium-ion battery using the CuPE as the current collector at the graphite anode and observed a near 100% and 10% increase in energy density concerning the total mass and total volume of the anode, respectively. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) have received great attention as promising candidates for next-generation energy-storage systems due to their high theoretical energy density. However, their practical energy density is limited by a large electrolyte-to-sulfur (E/S) ratio (>10 µL electrolyte/mg s), and their cycle performance encounters challenges from electrode passivation and Li dendrite formation. In this work, a dual-functional electrolyte additive of tetraethylammonium nitrate (TEAN) is presented to address these issues. NO3− as a high-donor-number (DN) salt anion can promote polysulfide dissolution, increase sulfur utilization, and alleviate electrode passivation. The tetraethylammonium cation can adsorb around Li protrusions to form a lithiophobic protective layer to inhibit the formation of Li dendrites. TEAN LSBs show improving capacity, cycling stability, and higher coulombic efficiency under lean electrolyte (5 μL electrolyte/mg s) conditions. [ABSTRACT FROM AUTHOR]

To address the toxicity concern of extensively used chlorobenzene (CB) and toluene antisolvents, it is urgent to explore green and more efficient antisolvents. In this work, a general and highly reproducible methodology of employing CsPbI3 nanocrystals (NCs) functionalized green alkanes with ultralow‐polarity (Alkane/NCs) as antisolvents to fabricate high‐quality perovskite films is reported. Compared with the CB processed, the perovskite films with much improved quality and high‐orientation are achieved by the Alkane/NCs approach. NCs in the alkane antisolvents are proven to provide enough heterogeneous nuclei, solving effectively the discontinuous film problem encountered from using pure alkanes. Strikingly, the lattice anchoring effect of NCs accounts for the high‐orientation growth of the perovskite films as revealed directly by cryo‐electron microscopy (cryo‐EM). Moreover, the phase segregation that easily occur in the CB processed perovskite film is successfully suppressed by the Alkane/NCs method. The optimal device conversion efficiency is enhanced from 21.59% to 23.10% from CB to octane (OCT)/NCs. Impressively, the alkane/NCs processed perovskite films and their devices exhibit much improved stability over CB, with the conversion efficiency remaining at 94% of its initial value after 500 h light soaking for OCT/NCs device, while the CB device fails at around 100 h. [ABSTRACT FROM AUTHOR]

With the growing prosperity of optical systems, the demand for high-precision optical components is becoming increasingly urgent. The mid-spatial frequency error generated on the optical components surface during the manufacturing process has become a bottleneck that restricts the improvement of the manufacturing accuracy of optical components. In this review, the processing techniques and polishing principles for optical components manufacturing are first briefly described and the source of mid-spatial frequency error is analyzed in detail. Then, several widely adopted suppression techniques in optical components manufacturing for mid-spatial frequency error are introduced in detail, such as the optimization methods for polishing path and polishing tool structure, and ion beam layer removal method. Moreover, their basic concepts, polishing mechanisms, development history, and characteristics are presented. Finally, the development of suppression techniques of mid-spatial frequency error for optical polishing is summarized and prospected. This paper analyses the problems of mid-spatial frequency error in optical components manufacturing, which may be worth investigating in the future. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium batteries (ASSBs) enabled by solid‐state electrolytes (SEs) including oxide‐based and sulfide‐based electrolytes have gained worldwide attention because of their intrinsic safety and higher energy density over conventional lithium‐ion batteries (LIBs). However, despite the high ionic conductivity of advanced SEs, ASSBs still exhibit high overall internal resistance, the most significant contributor of which can be ascribed to the cathode‐SE interfaces. This review seeks to clarify the critical issues regarding the cathode‐SE interfaces, including fundamental principles and corresponding solutions. First, major issues concerning electro‐chemo‐mechanical instability between cathodes and SEs and their formation mechanisms are discussed. Then, specific problems in oxides and sulfides and various solutions and strategies toward interfacial modifications are highlighted. Efforts toward the characterization and analysis of cathode‐SE interfaces with advanced techniques are also summarized. Finally, perspectives are offered on several problems demanding urgent solutions and the future development of SE applications and ASSBs. [ABSTRACT FROM AUTHOR]

The electrochemical stability window of the electrolyte solution limits the energy content of non-aqueous lithium metal batteries. In particular, although electrolytes comprising fluorinated solvents show good oxidation stability against high-voltage positive electrode active materials such as LiNi0.8Co0.1Mn0.1O2 (NCM811), the ionic conductivity is adversely affected and, thus, the battery cycling performance at high current rates and low temperatures. To address these issues, here we report the design and synthesis of a monofluoride ether as an electrolyte solvent with Li-F and Li-O tridentate coordination chemistries. The monofluoro substituent (-CH2F) in the solvent molecule, differently from the difluoro (-CHF2) and trifluoro (-CF3) counterparts, improves the electrolyte ionic conductivity without narrowing the oxidation stability. Indeed, the electrolyte solution with the monofluoride ether solvent demonstrates good compatibility with positive and negative electrodes in a wide range of temperatures (i.e., from −60 °C to +60 °C) and at high charge/discharge rates (e.g., at 17.5 mA cm−2). Using this electrolyte solution, we assemble and test a 320 mAh Li||NCM811 multi-layer pouch cell, which delivers a specific energy of 426 Wh kg−1 (based on the weight of the entire cell) and capacity retention of 80% after 200 cycles at 0.8/8 mA cm−2 charge/discharge rate and 30 °C. The energy content of non-aqueous lithium batteries is limited by the electrochemical stability window of the electrolyte solution. Here, the authors report a monofluoride ether-based electrolyte to stabilize high-voltage lithium metal batteries at high current rates and low temperatures. [ABSTRACT FROM AUTHOR]

The realization of high‐performance thick S cathodes is a critical step to achieve high energy density lithium–sulfur (Li–S) batteries. However, it normally requires a complicated and time‐consuming fabrication processes to obtain high‐performance S cathodes with high mass loading. On the other hand, thick S cathodes fabricated with high‐speed slurry coating method show poor flexibility, capacity, and cycle life due to unpredictable electrode cracking. Herein, an industrial‐speed cracking‐controlled slurry coating method to generate mosaic‐like cracks in the S cathode is developed, which provides vertical channels to facilitate the rapid diffusion of electrolyte, adequate space to accommodate the volume expansion during cycling, and strain‐releasing structure to achieve high flexibility. With this simple method, thick Mosaic‐S cathodes (9 mAh cm−2) provide outstanding energy density, long cycle life, and outstanding flexibility under dynamic bending. This work paves the way for scalable fabrication of high‐performance S cathodes in the near future. [ABSTRACT FROM AUTHOR]

As a promising candidate of current solid-state electrolytes with various advantages, such as broad electrochemical stability window, high thermal stability, and chemical stability, garnet-type solid-state electrolyte Li7La3Zr2O12 (LLZO) attracts extensive research attention. Researchers usually use the element doping method to improve the lithium ion conductivity of LLZO and to stabilize the cubic phase. However, the improvements either increase the cost of raw materials or need complex process. In this work, the preparation process of Al-doped LLZO is optimized by a simple post-doping method (LLZO-Al), and the as-prepared LLZO-Al shows a high lithium ion conductivity of 5.331 × 10−4 S cm−1 and an activation energy of 0.25 eV at room temperature. In addition, the LLZO-Al exhibits excellent stability against Li in LiǁLLZO-AlǁLi symmetric cell, and the LiNi0.8Co0.1Mn0.1O2 (NCM811)ǁLLZO-AlǁLi solid-state cell delivers a stable cycle of 120 cycles at 0.1C. This work offers a low-cost preparation method of LLZO-based solid-state electrolytes with high ionic conductivities for high-energy solid-state lithium metal batteries. [ABSTRACT FROM AUTHOR]

Flexible all solid-state batteries that combine polymer electrolytes and lithium metal are required for powering wearable electronic devices as they embody high flexibility, safety and energy density. However, it has been challenging to develop room temperature flexible solid-state batteries because of the low ionic conductivities of polymeric ion conductors. Here, we report a highly conductive polymer electrolyte based on lowly viscous polyethylene oxide ion conductors confined inside an ultrastrong and ultrathin nanofibrous polyethylene membrane. The newly developed solid polymer electrolyte exhibits high room temperature charge transfer conductance (0.07 S) and excellent compatibility with Li metal (cycling time > 3500 hours at 0.1 mA cm−2) at 30 °C. Large-scale molecular dynamics simulations show that the high ionic conductivity is because of the enhanced segmental mobility of confined PEO inside the nanomembrane and the strong charge–dipole interactions between the PEO and lithium ions. This work provides a viable solution toward room temperature workable solid-state batteries that meet the requirements for wearable electronic devices. [ABSTRACT FROM AUTHOR]

Gas generation induced by parasitic reactions in lithium‐metal batteries (LMB) has been regarded as one of the fundamental barriers to the reversibility of this battery chemistry, which occurs via the complex interplays among electrolytes, cathode, anode, and the decomposition species that travel across the cell. In this work, a novel in situ differential electrochemical mass spectrometry is constructed to differentiate the speciation and source of each gas product generated either during cycling or during storage in the presence of cathode chemistries of varying structure and nickel contents. It unambiguously excludes the trace moisture in electrolyte as the major source of hydrogen and convincingly identifies the layer‐structured NCM cathode material as the source of instability that releases active oxygen from the lattice at high voltages when NCM experiences H2 → H3 phase transition, which in turn reacts with carbonate solvents, producing both CO2 and proton at the cathode side. Such proton in solvated state travels across the cell and becomes the main source for hydrogen generated at the anode side. Mechanisms are proposed to account for these irreversible reactions, and two electrolyte additives based on phosphate structure are adopted to mitigate the gas generation based on the understanding of the above decomposition chemistries. [ABSTRACT FROM AUTHOR]

A CNC machine tool is process control equipment integrating machine, electricity, and liquid, which makes its fault diagnosis complex and special due to its own advanced, complex, and intelligent characteristics. Traditional diagnostic methods rely on the engineering experience of technical personnel, which incorporates human subjective factors, and can only perform qualitative analysis, resulting in low diagnostic efficiency. And through a single sensor to detect and diagnose the machine tool, the accuracy and credibility of the decision are low, and the system is also weak against interference. In this paper, we first summarize the composition and working principle of CNC machine tools and analyze the working condition signals generated by CNC machine tools and the sensors that collect the signals and decide to use a multisensor multisignal fusion-based approach to monitor the machine tool status. It is possible to obtain more effective and valuable information from the observed information through multiple sensors so that the goal of fusion can be achieved. In this paper, a multisensor fusion technique based on wavelet transform and neural network fusion is applied to a machine tool condition monitoring system. The theoretical basis of wavelet analysis and neural network is introduced, and the composition of the condition monitoring system and the process of applying multisensor fusion technology based on wavelet analysis and neural network in the condition monitoring system are given. A complete software and hardware system for online monitoring of CNC machine tools is established. In order to improve the accuracy of the mathematical model, the use of a neural network to fit the nonlinear data and the use of coarse set theory to simplify the relevant data can effectively solve the accurate establishment of the mathematical model in the error compensation method. The thermal error compensation method for CNC machine tools is proposed based on rough set theory, ant colony algorithm, and neural network. This paper first investigates the current development of error compensation technology for CNC machining centers, analyzes the various error sources of CNC machine tools, and finds out the influencing factors affecting the errors of CNC machine tools. [ABSTRACT FROM AUTHOR]

Solid polymer electrolyte with good thermal stability and flexibility is an excellent candidate for solid‐state lithium metal batteries, while its low ionic conductivity caused by high crystallinity limits its application at ambient temperature. Here a metal organic framework (zeolitic imidazolate framework‐8, ZIF‐8) composited comb‐like methoxy poly(ethylene glycol) acrylate polymer electrolyte (MCPE) with high ionic conductivity (9.96 × 10−5 S cm−1 at 30 °C) is prepared by an in situ UV polymerization method. The as‐prepared MCPE exhibits improved mechanical property due to the introduction of porous ZIF‐8 nanofillers, which is beneficial to suppress the growth of lithium dendrites. Consequently, the LiFePO4||MCPE||Li cells show a high capacity of 116 mAh g−1 at 30 °C and 0.5 C, and maintain 89.4% of initial capacity after 150 cycles with the average Coulombic efficiency of 99.9%. These results demonstrate that the MCPE shows great potential in solid‐state lithium metal batteries near room temperature. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries (LIBs) have been occupying the dominant position in energy storage devices. Over the past 30 years, silicon (Si)‐based materials are the most promising alternatives for graphite as LIB anodes due to their high theoretical capacities and low operating voltages. Nevertheless, their extensive volume changes in battery operation causes the structural collapse of Si‐based electrodes, as well as severe side reactions. In this review, the preparation methods and structure optimizations of Si‐based materials are highlighted, as well as their applications in half and full cells. Meanwhile, the developments of promising electrolytes, binders and separators that match Si‐based electrodes in half and full cells have made great progress. Pre‐lithiation technology has been introduced to compensate for irreversible Li+ consumption during battery operation, thereby improving the energy densities and lifetime of Si‐based full cells. More importantly, almost all related mechanisms of Si‐based electrodes in half and full cells are summarized in detail. It is expected to provide a comprehensive insight on how to develop high‐performance Si‐based full cells. The work can help us understand what happens during the lithiation process, the primary causes of Si‐based half and full cells failure, and strategies to overcome these challenges. [ABSTRACT FROM AUTHOR]

Cryogenic transmission electron microscopy (cryo-TEM) is a valuable tool recently proposed to investigate battery electrodes. Despite being employed for Li-based battery materials, cryo-TEM measurements for Na-based electrochemical energy storage systems are not commonly reported. In particular, elucidating the chemical and morphological behavior of the Na-metal electrode in contact with a non-aqueous liquid electrolyte solution could provide useful insights that may lead to a better understanding of metal cells during operation. Here, using cryo-TEM, we investigate the effect of fluoroethylene carbonate (FEC) additive on the solid electrolyte interphase (SEI) structure of a Na-metal electrode. Without FEC, the NaPF6-containing carbonate-based electrolyte reacts with the metal electrode to produce an unstable SEI, rich in Na2CO3 and Na3PO4, which constantly consumes the sodium reservoir of the cell during cycling. When FEC is used, the Na-metal electrode forms a multilayer SEI structure comprising an outer NaF-rich amorphous phase and an inner Na3PO4 phase. This layered structure stabilizes the SEI and prevents further reactions between the electrolyte and the Na metal. The solid electrolyte interphase (SEI) strongly affects the cycling behaviour of rechargeable alkali metal cells. Here, the authors investigate via cryo-electron microscopy the SEI formed on a Na metal electrode using fluoroethylene carbonate-containing electrolyte. [ABSTRACT FROM AUTHOR]

Solid Polymer Electrolytes (SPEs) exhibit great potential for application in high energy density solid-state lithium metal batteries owing to their excellent flexibility and high safety. However, the growth of lithium dendrites and poor interfacial contact between the electrolyte and electrode seriously hinder the wide commercial application. In this work, a composite solid electrolyte from halloysite nanotubes (HNTs), comb-like poly-ε-caprolactone (PCL), and lithium bis(fluorosulfonyl)imide (LiFSI) is fabricated via solvent-free in situ photoinitiated radical polymerization. On account of HNTs, the composite solid electrolyte (CSE) exhibits significantly improved room temperature ionic conductivity (6.62 × 10−5 S cm−1), a greater lithium transference number (0.55), and a higher electrochemical stability window (5.4 V) compared with the analog without HNTs (PSE). This is because the negatively charged outer silica surfaces of HNTs are enriched with Li+, while the positively charged aluminol inner surfaces accommodate FSI− anions, as clearly observed by TEM. As a bonus, the growth of lithium dendrites is remarkably alleviated. The superior electrochemical properties, in conjunction with refined interfacial contact by the in situ fabrication technique, enable the CSE-based lithium metal battery (at 1C and 60 °C for the LiFePO4 cathode) to have excellent cycling performance of high initial discharge capacity (155 mA h g−1), outstanding average coulombic efficiency (>99%), and extraordinary capacity retention (>92% over 600 cycles). Coupled with the high voltage LiMn0.5Fe0.5PO4 cathode (4.25 V), the solid-state lithium metal cell with the CSE also exhibits superior cycling performance, with an initial capacity of 134 mA h g−1 and a capacity retention of 87% over 250 cycles at 0.2C and 60 °C. [ABSTRACT FROM AUTHOR]

The ultimate bearing capacity of single pile is very important to engineering safety, so correctly predicting its value becomes an important part of engineering safety. Based on the traditional exponential curve model, a parameter optimization algorithm of the exponential curve model of single pile bearing capacity, which combines the golden section method and the linear least square method, is proposed. In order to verify the reliability of the proposed optimization algorithm, the measured data of the building engineering in the literature were optimized and calculated. Through comparison, it is found that the optimization algorithm is closer to the measured value than the traditional exponential curve model algorithm, which can better guide the engineering practice, and verify the effectiveness and superiority of the proposed parameter optimization method. [ABSTRACT FROM AUTHOR]

Highlights: A creative cooperative strategy involving silk fibroin/sericin is proposed for stabilizing high-performance flexible Li–S full batteries with a limited Li excess of 90% by simultaneously inhibiting lithium dendrites, adsorbing liquid polysulfides, and anchoring solid lithium sulfides. Such fabric Li–S full batteries offer high volumetric energy density (457.2 Wh L−1), high-capacity retention (99.8% per cycle), and remarkable bending capability (6000 flexing cycles at a small radius of 5 mm). Lithium–sulfur batteries are highly appealing as high-energy power systems and hold great application prospects for flexible and wearable electronics. However, the easy formation of lithium dendrites, shuttle effect of dissolved polysulfides, random deposition of insulating lithium sulfides, and poor mechanical flexibility of both electrodes seriously restrict the utilization of lithium and stabilities of lithium and sulfur for practical applications. Herein, we present a cooperative strategy employing silk fibroin/sericin to stabilize flexible lithium–sulfur full batteries by simultaneously inhibiting lithium dendrites, adsorbing liquid polysulfides, and anchoring solid lithium sulfides. Benefiting from the abundant nitrogen- and oxygen-containing functional groups, the carbonized fibroin fabric serves as a lithiophilic fabric host for stabilizing the lithium anode, while the carbonized fibroin fabric and the extracted sericin are used as sulfiphilic hosts and adhesive binders, respectively, for stabilizing the sulfur cathode. Consequently, the assembled Li–S full battery provided a high areal capacity (5.6 mAh cm−2), limited lithium excess (90%), a high volumetric energy density (457.2 Wh L−1), high-capacity retention (99.8% per cycle), and remarkable bending capability (6000 flexing cycles at a small radius of 5 mm). [ABSTRACT FROM AUTHOR]

To improve the machining accuracy and stability of CNC machine tools, the lead screw is divided into several segments, and the action law of single section thermal deformation is analyzed, then the thermal deformation model of lead screw base on subsection processing is established. Then the relative relation of thermal deformation of each segment, the cumulative thermal drift of thermal deformation of each segment itself, the total thermal deformation of the free end of lead screw, and the relationship between them are obtained. Then, a segmented thermal compensator based on PLC for CNC system is developed. The thermal error of each segment of the lead screw is detected and compensated separately, and then the thermal error of the segment where the machine tool worktable moves to the different segment of the lead screw is compensated. Tests show that the segmented thermal compensator has achieved good actual compensation effect, so that the positioning error caused by thermal deformation of each shaft can be reduced by more than 50%. [ABSTRACT FROM AUTHOR]

The large‐scale application of Si‐based anodes is impeded by their fast capacity decay, which is mainly attributed to the huge volume expansion upon cycling. The employment of functional binders is one efficient method to mitigate this issue. In this work, a four‐armed polyacrylic acid (4A‐PAA) homopolymer is explored as a remarkably effective binder for Si‐based anodes. The 4A‐PAA binder is prepared via an atom transfer radical polymerization, followed by ester hydrolysis. Compared to the conventional linear polyacrylic acid (PAA) binder, the 4A‐PAA not only shows enhanced toughness due to its decreased molecular regularity and intramolecular hydrogen bond but also exhibits increased binding strength because of its multidimensional binding structure. As a result, the SiOx/graphite electrode using the 4A‐PAA retains a capacity retention of 89.1% and a capacity of 558.1 mAh g−1 after 200 cycles at 0.16 A g−1, which are superior to the PAA electrode, corresponding to 80.4% and 469.3 mAh g−1, respectively. The improved performance is attributed to the employment of the 4A‐PAA, which mitigates the volume change of the SiOx/graphite anode. This work not only offers a promising binder for Si‐based anodes but also presents a universal solution for other anodes with high volume expansion during cycling. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid perovskites (OIHP) have attracted a great deal of attention as promising light-emitting materials, because of their low-cost production via simple solution processing, high color purity, and easily tunable bandgaps. Nevertheless, the fabrication of OIHP films for light-emitting diodes generally requires complicated post-treatments, such as an anti-solvent dripping process, owing to the poor film forming property of the perovskite precursor solution. In this work, we employed an ionic liquid, methylammonium acetate (MAAc), as an additive to optimize the growth of FAPbBr3 perovskite films via an anti-solvent-free approach. The influence of MAAc on the crystallization kinetics of FAPbBr3 phase and optoelectronic properties of the resulting perovskite films have been systematically investigated. Our results demonstrate that MAAc is an effective modifier for creating perovskite films with reduced grain size, homogeneous grain distribution, and smooth surface, leading to an enhanced average lifetime of the excitons. Perovskite light-emitting diodes (PeLEDs) containing FAPbBr3 films obtained via incorporating 10 vol% MAAc as an additive exhibited considerably suppressed leakage current, and a significant enhancement in current efficiency (CE) from 0.027 to 4.85 cd A−1. These findings reveal that the incorporation of a suitable additive could play a beneficial role in the formation of well-optimized perovskite films, which would ultimately lead to the realization of PeLEDs with improved performance. [ABSTRACT FROM AUTHOR]

Using a co-precipitation approach, we introduce Co into LiNi0.5Mn1.5O4 to prepare a series of Co-doped cathode materials in which the Co substitutes partial Ni and Mn. We then systematically study the effects of Co doping at these various sites. The structural and electrochemical properties are investigated by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis, galvanostatic charge–discharge tests, and electrochemical impedance spectroscopy. The Co-doped samples experience a slight capacity loss, but their cycling stability and rate properties are significantly improved. When Ni and Mn are simultaneously substituted, the capacities at 0.1 C and 2.0 C of a battery using this doped material as the cathode stay at 99.7% and 96.8%, respectively, after 80 cycles, which is much better than the results for a battery with undoped material as the cathode. [ABSTRACT FROM AUTHOR]

The incorporation of inorganic fillers into poly(ethyleneoxide)(PEO)-based solid polymer electrolytes (SPEs) is well known as a low-cost and effective method to improve their mechanical and electrochemical properties. Porous zeolitic imidazolate framework-8 (ZIF-8) is firstly used as the filler for PEO-based SPEs in this work. Due to the introduction of ZIF-8, an ionic conductivity of 2.2 × 10−5 S/cm (30 °C) is achieved for the composite SPE, which is one order of magnitude higher than that of the pure PEO. ZIF-8 also accounts for the broader electrochemical stability window and lithium ion transference number (0.36 at 60 °C) of the composite SPE. Moreover, the improved mechanism of ZIF-8 to the composite SPE is investigated by zeta potential and Fourier transform infrared spectrograph characterizations. The stability at the composite SPE/lithium interface is greatly enhanced. The LiFePO4||Li cells using the composite SPE exhibit high capacity and excellent cycling performance at 60 °C, i.e., 85% capacity retention with 111 mA·h/g capacity retained after 350 cycles at 0.5 C. In comparison, the cells using the pure PEO show fast capacity decay to 74 mA·h/g maintaining only 68 capacity. These results indicate that the PEO-based SPEs with ZIF-8 are of great promise for the application in solid-state lithium metal batteries. [ABSTRACT FROM AUTHOR]

Self-healing soft matters have attracted much attention because of their extraordinary performance for extending working life of materials. To utilise sunlight to help self-healing of liquid-crystalline gels composed of one low-mass liquid crystal (5CB) and one hyperbranched polymer (lignin-graft-PMMA), a low content of graphene oxide (GO) and one azobenzene compound are doped as photoresponsive additives. Upon irradiation of UV light, the azobenzene can induce gel-sol transition due to the photoinduced molecular cooperative motion, thus surface dents can be repaired. On the other hand, GO functions as the nanoscale heat source because of the photothermal effect under exposure of visible (VIS) or NIR light, heating the gel to undergo gel-sol transition for mending surface cracks. In addition, the mechanical properties of the gels are also improved by addition of GO. This NIR-VIS-UV light responsive liquid-crystalline gel shows highly effective gel-sol transition upon direct solar radiation because of the coexistence of both photochemical and photothermal effect. Furthermore, these sunlight-assistant self-healing gels also show anisotropy and orientation just like other liquid-crystalline materials, enabling them to find various advanced applications with longer service life. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) are considered promising candidates for the next‐generation energy‐storage systems due to their high theoretical capacity and prevalent abundance of sulfur. Their reversible operation, however, encounters challenges from both the anode, where dendritic and dead Li‐metal form, and the cathode, where polysulfides dissolve and become parasitic shuttles. Both issues arise from the imperfection of interphases between electrolyte and electrode. Herein, a new lithium salt based on an imide anion with fluorination and unsaturation in its structure is reported, whose interphasial chemistries resolve these issues simultaneously. Lithium 1, 1, 2, 2, 3, 3‐hexafluoropropane‐1, 3‐disulfonimide (LiHFDF) forms highly fluorinated interphases at both anode and cathode surfaces, which effectively suppress formation of Li‐dendrites and dissolution/shuttling of polysulfides, and significantly improves the electrochemical reversibility of LSBs. In a broader context, this new Li salt offers a new perspective for diversified beyond Li‐ion chemistries that rely on a Li‐metal anode and active cathode materials. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) have become one of the most prevalent techniques for feasible and fascinating energy storage devices used in portable electronics and electric vehicles; however, they still face a significant challenge due to the complicated electrode–electrolyte interface (EEI), which is closely related to the chemical/electrochemical instability of high-capacity high-voltage electrodes and electrolytes. In particular, the decomposition of an electrolyte on the electrode surface is unambiguously regarded as a crucial controlling factor for the obtainable capacity, rate capacity, and interfacial chemistries of batteries. Previously, significant efforts have been devoted toward modifying the EEI with remarkable progress. The incorporation of a small dose of foreign molecules, called film-forming additives, is regarded as one of the most economical and effective approaches to circumvent these predicaments. In this regard, this review provides an overview of various film-forming additives used for classified anodes and cathodes, aiming at emphasizing the state-of-the-art developments in the electrolyte research. Moreover, the authors intend to help the readers arouse new ideas and easily identify the additives suitable for their target materials, paving the way for greater progress in the lithium-ion battery community. [ABSTRACT FROM AUTHOR]

Correction to: I Nature Communications i https://doi.org/10.1038/s41467-023-36793-6, published online 25 February 2023 Supplementary Figure 30 of this article contained an error. These authors contributed equally: Guangzhao Zhang, Jian Chang. [Extracted from the article]

Abstract: Electrochromism has received increasing attention due to its unique electrochromic feature and the induced applications. This review provides an overview on the recent developments in the synthesis and application of the electrochromic metal oxides in smart windows, display devices, e‐skins, and multifunctional energy storage devices. The main cathodic and anodic electrochromic metal oxides are surveyed here, with the discussion of representative examples in details. The current state‐of‐the‐art research activities of the derived multifunctional electrochromic devices are highlighted, i.e., material systems, components, structures, morphology, the resulting performance, etc. Major challenges and potential solutions are also discussed. Additionally, the future perspective on the development trends in electrochromic metal oxides and the commercialization of relevant devices is also proposed. [ABSTRACT FROM AUTHOR]