Abstract Active particle materials with high capacity, safety, and abundance, such as Sn and Si‐based materials, and nickel‐rich layered materials like LiNixCoyMn1−x−yO2 (with x≥0.8) are viewed as promising candidates for the evolution of next‐generation batteries. However, structural degradation during cycling often limits the application of these active particle materials. Currently, research efforts are focused on developing new characterization techniques to understand the structural degradation mechanisms of active particle materials during the cycle, to improve their performance. This paper reviews advanced single‐particle electrochemical and structural characterization techniques and their main findings. These findings included lattice displacement and rotation, microstructure evolution, and reaction kinetics of single‐particle during cycling. In addition, we also discuss the potential future applications and developments of single‐particle measurement technologies.

The inhomogeneity of the multi-physics field significantly has played a key role on the lifetime degradation of the prismatic battery, especially in battery modules. It is important to improve the cycle performance by optimizing structure design of the module. Here, a novel 3D metal lattice structure with equal stiffness is developed for interlayer structure in the battery module to lighten the non-uniform temperature and pressure distributions. The lattice sandwich structure, with high specific stiffness and lightweight properties, is optimized through simulation using a combination of ABAQUS and FLOEFD software. A 3D metal lattice splint with runner heat transfer is reasonably designed. The non-uniformity coefficients of pressure and temperature between single batteries decrease by 90.8 % and 35.6 %, respectively, indicating the excellent mechanical properties and heat transfer performance of lattice structure. Furthermore, the capacity degradation rate of the module with lattice splint reduces by 18.7 % compared to the pristine module. The lattice structure can provide the basis for optimizing the structure of battery to improve safety and lifetime.

The calendering process, which is a common compaction technique, serves as the final step in the manufacturing of lithium-ion battery electrodes. Calendering plays an irreplaceable role in enhancing the volumetric energy density and electrochemical performance due to the densification of pore structure. To investigate the densification of active particles, this study designs and develops a micro-CT loading device, which can capture the in-situ evolution during the electrode compression. By combining the in-situ CT with discrete element method (DEM) scheme, we analyze the internal load transfer paths, particle contacts, and pore structure evolution during the densification. The results indicate that the particle compaction process can be divided into two stages, exhibiting a state transition from a non-uniform compaction stage to a uniform compaction stage, and the large particles show a higher breakage risk after over-compaction. This study successfully in-situ tracks the densification during electrode compression and it would promote a deeper understanding of the evolution of electrode microstructure and particle fracture, and optimize the structures and performance of electrodes.

Cobalt-free Lithium-rich layered oxides (LRLOs) are promising cathodes for low-cost and high-energy-density Li- ion batteries. However, their remarkable capacity comes with challenges including structural degradation, irreversible oxygen release and sluggish kinetics. Herein, we conduct a one-step dual-modified strategy by yttrium doping and Li3PO4 surface modification. Combining density-functional theory calculations with in-situ Xray diffraction and in-situ differential electrochemical mass spectrometry, the Y3+ doping and Li3PO4 nano coating modified LRLOs is demonstrated has an excellent structural stability with enhanced Li+ diffusion kinetics and stabilized oxygen lattice. Excellent rate performance and thermal stability are achieved: high discharge specific capacity of 221 mAh center dot g-1 at room temperature (96.5 % at 1 C after 100 cycles) and incredible discharge specific capacity of 210 mAh center dot g-1 at 55 degrees C (91.8 % at 2 C after 100 cycles). This work resolves the safety and stability issues and provides a feasible strategy for Co-free LRLOs.

As a promising solution for solid-state batteries with high energy density and safety, understanding the mechanism of fast ion conduction in polymer-ceramic composite solid-state electrolytes (CSEs) is still a challenging task. Herein, we understand the enhanced ion conduction in CSEs using a series of ionic spectra. Ionic insight is extended to ion conduction in CSEs, resolving the mechanism of fast ion migration. With the cooperation of enhanced interface and filler ion conduction, the CSE with a conductive filler exhibits ionic conductivity higher than that of CSEs with insulating fillers. Volume and filler strategies of CSE design are proposed based on volcanic maps of conductivity. An equivalent circuit is established to describe the conduction mechanism of CSEs. Specifically, Rinterface and Rfiller are in parallel to describe the cooperation of interface and filler conduction. They are in series with Rbulk, which represents a competition between the fundamental matrix and enhanced interface conduction. The proposed conduction model is verified though the energy storage performance of solid-state batteries; a fast dynamic process promises a better rate performance and cycling stability of solid-state batteries. These results provide deep insights into fast ion conduction in ceramic-polymer CSEs, which are indispensable to develop high-performance solid-state batteries.

Cuprous oxide (Cu2O) is an ideal visible light catalyst owing to its narrow band gap, environmental benignity and abundant storage; however, the fast recombination of photogenerated charge carriers and poor stability of Cu2O has impeded its application in photocatalysis. Herein, we demonstrate that Cu2O@C nanocomposite can spontaneously evolve from a methanol aqueous solution containing cupric ions under the induction of irradiation. Compared with the traditional carbon coating method, the Cu2O@C nanocomposite obtained by the photo-induced in-situ synthesis can reserve superior original characteristics of the semiconductor under mild reaction conditions, promote the charge transfer and enhance the separation efficiency of charge carriers; in addition, the carbon shells can also effectively prevent Cu2O from photo-corrosion. As a result, the Cu2O@C nanocomposite exhibits excellent photocatalytic activity in the hydrogen evolution in comparison with the Cu2O particles; the H2 evolution rate over the Cu2O@C nanocomposite reaches 1.28 mmol/(g·h) under visible light, compared with the value of 0.065 mmol/(g·h) over Cu2O. Moreover, the Cu2O@C nanocomposite displays good cycle stability, viz., without any deactivation in the catalytic activity after five cycles.

The separator is the weakest mechanical part of a lithium‐ion battery. The displacement load formed by the expansion of an electrode induces the microstructure evolution of the separator, such as decreasing porosity and increasing tortuosity, which affects its ability to transport Li+ and degrades battery performance. Herein, an in situ mechanical loading device combined with focused ion beam–scanning electron microscopy (FIB–SEM) is designed to reveal the real microstructure evolution of a separator under displacement loading. An image‐based finite‐element model is tailored to investigate the microstructure evolution and its nonuniformities of the separator at different deformation levels. The quantitative relationship between the separator porosity and external displacement load is presented based on the experimental and simulation results. Herein, new insight into the degradation mechanisms of commercial lithium‐ion batteries is provided.

Electrochemical actuators (EAs) with capabilities of triggering large deformation are attracting great interests because of their low stimulation voltage and high durability. However, porous electrode structures (PESs) with either a large unexpected strain or small-size inserted ions lead to small actuation strain and low energy transduction efficiency. To address this problem, an ideal electrode material, namely, pyrolytic graphite (PG), with an anisotropic densely stacked electrode structure (ASES), was proposed, and the optimal insertion ion, namely, AlCl4- with a large radius, was selected. Simulations show that an ASES presents an increased actuation strain and effectively eliminates unexpected strain. In addition, the insertion of AlCl4- into the graphite layers can lead to a directionally large volume expansion (>230%) due to the low energy barrier and large ionic radius. Experimental results reveal that the PG can expand/contract repeatedly with a high linear strain of approximate to 48% under a zero stress and approximate to 32% under a load of 2.5 MPa. EAs based on PG and AlCl4- achieve excellent actuation efficiency with an energy density of 105.89 J cm(-3), power density of 0.35 W cm(-3) and a high electromechanical transduction efficiency of up to 14.30%. This design method provides a significant way to develop high-performance EAs. (c) 2022 Elsevier Ltd. All rights reserved.

The energetic ion salt, TKX-50, has attracted great interests in the field of energetic materials due to its advantages of high enthalpy of formation, low sensitivity and low toxicity. However, the large aspect ratio and poor surface adhesion performance of its crystal are inconducive to the safe use and interfacial bonding for the preparation of composite energetic materials. To solve these problems, we introduced an anionic polymer, carboxymethyl cellulose acetate butyrate (CMCAB), as the crystal control agent and surface modifier for the recrystallization of TKX-50 by the anti-solvent method. The effects of CMCAB on the morphology, internal structure, surface elemental composition, mechanical sensitivity, specific heat capacity (C-p) and thermal stability of TKX-50 were investigated. It was found that the morphologies of the TKX-50 recrystallized in the anti-solvents containing CMCAB were better with lower aspect ratios and narrower particle size distributions. A discontinuous CMCAB coating layer was formed on the crystal surfaces due to the electrostatic interaction between CMCAB and TKX-50, resulting in the CMCAB@TKX-50 complex. The coating degree and surface modification were more significant with the increase of CMCAB concentration. The CMCAB coating reduced the friction sensitivity of TKX-50 by 12-38%, meanwhile, the impact sensitivities of CMCAB@TKX-50 prepared at different CMCAB concentrations remained at the low levels of 4-12%. The DSC analysis revealed that the C-p of CMCAB@TKX-50 was generally higher than that of TKX-50. The bigger the crystals of CMCAB@TKX-50, the greater the C-p and the higher the thermal stability. The peak decomposition temperature of the first stage, the activation energy (E-a) and pre-exponential factor (A) of CMCAB@TKX-50 were generally higher than those of TKX-50, suggesting better thermal stability and safety of CMCAB@TKX-50 than TKX-50. The CMCAB@TKX-50 prepared in our work not only shows superior safety performance, but also is well compatible with the traditional binder, cellulose acetate butyrate (CAB). The good dissolution properties of CMCAB make CMCAB@TKX-50 more suitable for the preparation of polymer-bonded explosives (PBX), which can promote the application of TKX-50 in PBX.

以2016-2020年具有污染性质的制造业上市公司为研究样本,从环境绩效和全要素生产率两个方面研究了数字化转型对企业高质量发展的影响效应及边界条件.研究发现:数字化转型与企业环境绩效之间存在正U型关系,与企业全要素生产率之间存在倒U型关系;沉淀性冗余资源负向调节了数字化转型与企业全要素生产率间的倒U型关系,非沉淀性冗余资源正向调节了数字化转型与企业环境绩效间的正U型关系;进—步分析发现,市场竞争度会减弱非沉淀性冗余资源的调节作用和强化沉淀性冗余资源的调节作用.

企业作为区域创新系统中的重要创新主体,对促进区域创新产出具有重要影响.利用2012～2018年中国省级面板数据,引入产学研协同发展和对外开放度两个重要变量,实证研究了企业研发投入如何促进区域创新产出的问题.结果表明:企业研发投入对区域创新产出存在正向显著影响;企业研发投入会促进产学研协同发展水平的提升,且产学研协同发展在企业研发投入与区域创新产出之间存在部分中介作用;对外开放度在企业研发投入与产学研协同发展之间起到正向调节作用.研究结论对推动区域创新发展具有重要的理论和现实意义.

The evolution of the microstructure of a battery electrode is closely related to battery performance. Characterization and visualization of the evolution of the microstructure is essential for optimization of manufactured electrodes. The validity of the battery structure representation affects the accuracy of the extracted microstructure parameters. In this study, a mini-cylindrical battery is designed to allow microstructure parameters to be obtained at different states of charge, bearing in mind the influence of the real battery structure. An argon-ion cross-section polisher is used to obtain a large area of the electrode for observation. In addition, an image segmentation method based on a modified U-Net neural network is developed to enhance the quality of the extracted microstructure. The relationship between porosity and thickness at different states of electrode charge is presented through experiments and deep learning of images. This method provides new insight into the evolution of electrode microstructure and can potentially guide the manufacturing of lithium-ion batteries.

With the advent of flexible/wearable electronic devices, flexible lithium-ion batteries (LIBs) have attracted significant attention as optimal power source candidates. Flexible LIBs with good flexibility, mechanical stability, and high energy density are still an enormous challenge. In recent years, many complex and diverse design methods for flexible LIBs have been reported. The design and evaluation of ideal flexible LIBs must take into consideration both mechanical and electrochemical factors. In this review, the recent progress and challenges of flexible LIBs are reviewed from a mechano-electrochemical perspective. The recent progress in flexible LIB design is addressed concerning flexible material and configuration design. The mechanical and electrochemical evaluations of flexible LIBs are also summarized. Furthermore, mechano-electrochemical perspectives for the future direction of flexible LIBs are also discussed. Finally, the relationship between mechanical loading and the electrode process is analyzed from a mechano-electrochemical perspective. The evaluation of flexible LIBs should be based on mechano-electrochemical processes. Reviews and perspectives are of great significance to the design and practicality of flexible LIBs, which is contributed to bridging the gap between laboratory exploration and practical applications.

Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo2CTx MXene(NBF-CoSe/Mo2CTx)to enhance the hydrogen evolution reaction(HER)and supercapacitor activ-ities via an ionic liquid-mediated method.Se vacancy pairs and heteroatom doping enable the realloca-tion of local electron states and add active sites,improving the electrochemical activity of NBF-CoSe/Mo2CTx with high HER activities over a broad range of pH.At a current density of 10 mA cm-2,over-voltages of 70 and 81 mV are respectively produced in 0.5 M H2SO4 and 1 M KOH.The optimal structure also exhibits outstanding electrochemical performance in an asymmetric supercapacitor with an energy density of 34.2 Wh kg-1 at a power density of 15989.6 W kg-1.This study opens new avenues for the introduction of Se vacancies and heteroatom doping to improve the application performance.

Inexpensive, easy-to-implement coatings exhibiting extremely low reflectance within a broad spectral range, and good adhesion to substrates are in high demand for high-precision optical instruments and solar energy harvesting. Herein, we demonstrate a highly absorbing coating based on hollow carbon nanospheres (HCSs). The coatings are formed via a simple and high-performing air-spraying process with a tailored paint formulation containing HCSs as an absorbing pigment and a fluororesin as a binder. By optimizing the pigment/binder mass ratio (P/B), we produce functional coatings that exhibit solar absorptance up to 0.985 and good adhesion to aluminum sheets of grade 2 (according to the ISO 2409 standard). The excellent solar absorptance of the obtained coatings results from their hierarchical nano- and microscale surface morphology, providing a refractive index gradient on the air-coating interface as well as remarkable light trapping performance. The former is due to the hollow structure in carbon spheres, which is preserved after the addition of the binder because the size of binder particles is larger than the holes on the shell of the HCSs. The latter is attributed to the micronodules and micropits of the coating surface formed by the agglomeration of the HCSs, which enhances absorption by multiple scattering.

Because multifunctional ceramics are widely used in the electronics, manipulating composition and structure of the electronic ceramics aim at improving the performance of the target material for appropriate applications. However, the composite materials with multiphases and multicomponents could be achieved by mixing the nanomaterials with various preparing methods or technologies, which generally require a bunch of experimental design to obtain the target products. For achieving the goals, a novel electrochemical approach for preparing functional ceramic materials is demonstrated via ion extraction from the A site of perovskite BiFeO3 (BFO) ceramic particles, and whereby a single-phase perovskite BFO could be evolved into multiphase and multicrystalline homogeneous composites. With gradual changes in material particle size, composition, structure, and morphology upon electrochemical Bi3+ ion extraction, the magnetic and electromagnetic properties of the decomposed BFO along with the generated multiphase and multicrystalline composites would present pronounced evolutionary behaviors, compared with original BFO. Apparently, such titration method upon electrochemical ion extraction could be employed to manipulate the properties of the functional ceramics. The simple strategy of electrochemical manipulation BFO would be applied to certain materials with electrochemical activity to achieve the target performance.

Single-atom catalysts (SACs) exhibit excellent catalytic performance owing to their high atom utilization efficiency. Meanwhile, members of the 2D MXenes family, particularly Mo2CTx, have recently been identified as promising electrocatalyst and have been used as a potential catalyst supports to anchor single-atom. However, it still has a potential to enhance the performance by increasing surface areas and active sites. Herein, we employ an ionic liquid for coprecipitation with ReO4− salt to synthesis N-, B-, and F-atom-doped ReS2, which is grown evenly on the surface of MoC2Tx MXene, followed by a uniform loading of single-atom Pt on NBF-ReS2. The two-dimensional morphology allows ReS2 to provide a large surface area for loading more single Pt atoms. In addition, the introduction of N, B, and F via the ionic liquid increases the number of active sites. Owing to these properties, the resulting catalyst exhibits extraordinary catalytic activity and stability during the oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction. Liquid or flexible solid-state rechargeable Zn–air batteries equipped with the proposed Pt/NBF-ReS2/Mo2CTx system are also demonstrated to exhibit superior performance. This work presents a general strategy of preparing heteroatom-doped and layered nanostructures with a uniform loading of single-atom to form conductive electrodes for HER and Zn–air batteries.

Precise optical and thermal regulatory systems are found in nature, specifically in the microstructures on organisms' surfaces. In fact, the interaction between light and matter through these microstructures is of great significance to the evolution and survival of organisms. Furthermore, the optical regulation by these biological microstructures is engineered owing to natural selection. Herein, the role that microstructures play in enhancing optical performance or creating new optical properties in nature is summarized, with a focus on the regulation mechanisms of the solar and infrared spectra emanating from the microstructures and their role in the field of thermal radiation. The causes of the unique optical phenomena are discussed, focusing on prevailing characteristics such as high absorption, high transmission, adjustable reflection, adjustable absorption, and dynamic infrared radiative design. On this basis, the comprehensive control performance of light and heat integrated by this bioinspired microstructure is introduced in detail and a solution strategy for the development of low-energy, environmentally friendly, intelligent thermal control instruments is discussed. In order to develop such an instrument, a microstructural design foundation is provided.

Aiming at solving the uncontrollability in the properties of chitosan, we synthesized two chitosan-mimetic polymers, the homopolymer mimicPHNIand the copolymer mimicPHNI-PHNIA, by ring-opening metathesis polymerization (ROMP).