The degradation trend of battery State of Health (SOH) varies across different operational phases of electric Vertical Takeoff and Landing (eVTOL) aircraft. To address the challenge of SOH prediction for eVTOL, an adaptive hybrid forecasting model based on Mamba-Informer is proposed. The model features a parallel architecture combining Mamba and Informer branches. The Mamba branch leverages the selective scanning mechanism of the Selective State Space Model (SSM) to process long sequences, while the Informer branch utilizes the ProbSparse self-attention mechanism to filter crucial queries and identify short-term SOH fluctuations. A learnable adaptive gating unit is introduced to achieve complementary advantages between the two branches, automatically adjusting weight allocation based on the characteristics of the input data distribution. This enables adaptive modeling of irregular SOH degradation. Experiments demonstrate that the proposed method outperforms models such as LSTM, Transformer, and standalone Mamba in key metrics including RMSE (0.7466%), MAE (0.5862%), and R2 (0.9861), exhibiting robust generalization capability.

This study demonstrates a reliable wafer-level Au/Si eutectic bonding technique suitable for hermetic packaging of MEMS resonators with small cavities (≤0.01 mm3). By optimizing the Au-Si eutectic bonding process, including outgassing/bonding time, heating/cooling rates, and the incorporation of a Pt barrier layer, significant improvements in bonding quality were achieved. The hermetically sealed cavities exhibited a vacuum level below 2 Pa, a shear strength exceeding 56.4 MPa, and an average helium leak rate of 2.85 × 10−9 atm·cc/s. Furthermore, the quality factors (Q factors) of packaged cantilevers increased substantially from 400 to over 60,000, indicating effective mitigation of air damping. These results suggest that this bonding technique holds considerable promise for the development of high-performance, small-volume, and cost-effective MEMS devices.

The cation design of the multi-component dynamic concentration electrolytes that simultaneously achieve effective phase transition prevention and rapid kinetic process is challenging but vital for enhancing the performance of low-temperature zinc-bromine flow batteries. Herein, we employ NH4+ as supporting electrolyte cation to break inherent trade-off between salting-out at low temperatures and ion transport kinetic from the alkali cations (K+, Na+ and Li+). Compared to commonly used K+ in the traditional electrolyte, NH4+ achieves an improved ability to prevent the phase transition of the electrolyte and obtains better ion transport property, which is a characteristic that Na+ and Li+ do not possess. Additionally, NH4+ can significantly enhance the cycling stability by appropriately increasing the solubility of polybromides. Consequently, the zinc-bromine flow batteries supported by NH4+ not only demonstrate sustained lifespan (>2,300 cycles at 40 mA cm-2, 40 mAh cm-2, over half a year) and consistent high-rate cyclic stability (charging at 200 mA cm-2, discharging at 80 mA cm-2, >3,300 h) at room temperature; they also exhibit stable cyclic stability (over 1,600 cycles at 40 mA cm-2) at -20 °C. This work provides an effective path for the design of complex electrolytes for low-temperature aqueous zinc-based flow batteries.

Cu-based alloys, which are known for their abundant electroactive sites and excellent stability, have emerged as promising electrocatalytic materials for sustainable energy conversion. Among the various synthetic strategies, wet chemical methods offer a mild, efficient, and controllable approach to precisely tailor the composition and structure of Cu-based alloys, thereby optimizing their electrocatalytic properties. This review highlights recent advances in wet chemical synthesis techniques, including hydrothermal, solvothermal, polyol, and seed-mediated methods. Furthermore, it explores the applications of Cu-based alloys in key electrocatalytic reactions, such as alcohol oxidation, carbon dioxide reduction, nitrogen-related transformations, hydrogen evolution, and oxygen reduction. Finally, the challenges and prospects of Cu-based alloy electrocatalysts are discussed, providing insights into the design and development of high-performance energy-conversion technologies.

Aqueous electrolytic Zn-MnO2 batteries hold great promise for energy storage applications owing to their high theoretical electromotive force and energy density. However, the zinc anode suffers from severe corrosion in strongly acidic electrolytes, leading to hydrogen evolution, low zinc utilization, and premature battery failure. To address these challenges, isoquinoline is introduced as an additive in a chloride-based acidic electrolyte. Isoquinoline molecules preferentially adsorb on the Zn surface and incorporate into the Zn2+ solvation sheath, thereby effectively suppressing zinc corrosion and enhancing Zn plating/stripping reversibility in both half-cell and full-cell configurations. At an optimized concentration of 500 mg L-1 isoquinoline, the modified electrolyte enables the electrolytic Zn-MnO2 battery to achieve outstanding cycling stability, delivering 3650 cycles with an average coulombic efficiency of 98%, demonstrating highly competitive cycling performance among reported electrolytic Zn-MnO2 systems. Furthermore, this electrolyte modulation supports the development of a zinc metal anode-free full cell, which delivers a high areal discharge capacity of ≈8 mAh cm-2 and maintains a stable discharge voltage plateau of ≈1.9 V. These findings underscore the pivotal role of isoquinoline in stabilizing the zinc interface and advancing the performance of electrolytic Zn-MnO2 batteries.

Metal oxides with conversion and alloying mechanisms are more competitive in suppressing lithium dendrites. However, it is difficult to simultaneously regulate the conversion and alloying reactions. Herein, conversion and alloying reactions are regulated by modulation of the zinc oxide bandgap and oxygen vacancies. State-of-the-art advanced characterization techniques from a microcosmic to a macrocosmic viewpoint, including neutron diffraction, synchrotron X-ray absorption spectroscopy, synchrotron X-ray microtomography, nanoindentation, and ultrasonic C-scan demonstrated the electrochemical gain benefit from plentiful oxygen vacancies and low bandgaps due to doping strategies. In addition, high mechanical strength 3D morphology and abundant mesopores assist in the uniform distribution of lithium ions. Consequently, the best-performed ZnO-2 offers impressive electrochemical properties, including symmetric Li cells with 2000 h and full cells with 81% capacity retention after 600 cycles. In addition to providing a promising strategy for improving the lithiophilicity and mechanical strength of metal oxide anodes, this work also sheds light on lithium metal batteries for practical applications. Oxygen vacancy and bandgap are simultaneously modulated by doping engineering to achieve high lithiophilicity and mechanical strength of lithium metal anodes. image

The novel Li-argyrodite solid-state electrolyte Li6.05P0.95Zr0.05S4.9O0.1Cl prepared via ZrO2 doping further obtains excellent lithium-metal compatibility and air stability while maintaining high ionic conductivity.

Lithium metals are considered to be the proverbial "holy grail" for lithium batteries. The integration of high-energy cathodes, such as sulfur or oxygen cathodes, enables the fabrication of high-energy storage devices. Nevertheless, energy storage systems based on lithium metals face a number of complex challenges, including matrix and interface concerns. State-of-the-art characterization techniques are prerequisites for solving present-day challenges. In contrast to electrons, protons or X-rays, neutrons exhibit a unique advantage of high penetration due to their electrical neutrality. This characteristic will have irreplaceable advantages in the operando characterization of high-energy storage devices that undergo gradual increases in volume or mass. More importantly, the nuclear scattering characteristics of neutrons interacting with matter make them more sensitive to lithium elements compared to X-rays. Therefore, neutron-based characterization may be a powerful tool in resolving current problems associated with lithium metal batteries. In this review, neutron techniques (including neutron diffraction, quasi-elastic neutron scattering, small angle neutron scattering, neutron reflectometry, neutron imaging and neutron depth profiling) are categorized and their applications in anodes, cathodes, electrolytes and electrochemical interfaces of lithium metal batteries are summarized, respectively. The potential application of neutron techniques in lithium metal battery components is prospected. The perspectives elucidated in this article may serve as a methodical manual for resolving the present challenges associated with lithium metal-based batteries and as inspiration for applying them to other high energy storage devices.

Garnet-type lithium-lanthanum-zirconium-oxygen (LLZO) oxide solid-state electrolytes (SSEs) have become one of the most promising SSEs for future deep space exploration because of their excellent energy density and mechanical strength. However, the effects of high-energy irradiation on LLZO-type oxide SSEs in the space domain are still unknown. To this end, the Ta-doped lithium-lanthanum-zirconium-tantalum-oxygen (LLZTO) SSE with high ionic conductivity at room temperature was prepared by a solid-phase reaction method, and the gamma-irradiation effects on the cell structure and performance (ionic conductivity, hardness, and elastic modulus) of the LLZTO SSE were investigated in detail. The results show that the gamma-irradiated electrolyte did not produce other heterogeneous phases, but the lattice spacing was subsequently reduced, which would be detrimental to the ionic transport in the lattice. In addition, the neutron diffraction data also illustrate that irradiation does not change the cell structure of the LLZTO SSE, but the decrease in Li1 occupancy at the tetrahedral-24d site will have a detrimental causal effect on ion transport. The impedance test at room temperature further demonstrated that after gamma-irradiation, the total resistance of LLZTO becomes larger and the ionic conductivity of the corresponding irradiated samples tends to decrease. Fortunately, the ionic conductivity retention of irradiated samples at low temperatures was higher than that of unirradiated samples (48.45 > 29.9%). The test results of nanoindentation indicate that the irradiated samples have high mechanical properties at a low load (2 mN), which can effectively prevent lithium dendrite penetration, and this is supported by the low electronic conductivity of the irradiated samples at room temperature. The first use of gamma-irradiation to probe its effect on the cell structure and properties (electrochemical and mechanical) of the LLZTO oxide SSE has important research implications for the development of oxide SSEs for aerospace applications.

Sulfide solid-state electrolytes (SSEs), as the most important component of all-solid-state batteries (ASSBs), have a profound impact on their performance. Among the many sulfide SSEs, Li-argyrodite SSEs have been extensively studied and are considered to be one of the most promising solid sulfide-based Li superionic conductors nowadays. However, the SSEs still have some drawbacks to be addressed, such as limited ionic conductivity at room temperature, incompatible electrode/electrolyte interface, low operating voltage window, and poor air stability. It is found that doping strategies have a non-negligible role in solving the above problems. In this review, we first introduce the crystal structures of Li-argyrodite SSEs and provide a detailed description of Li-ion transport in Li-argyrodite SSEs, followed by a detailed description of structure of the Li-sublattice. Next, the mechanism of doping strategies to enhance the ionic conductivity of Li-argyrodite SSEs is focused. Particular emphasis is provided on the ionic dynamics in doped Li-argyrodite SSEs. In addition, the effects of doping strategies (e.g., soft acid ions and metal oxides) on improving the performance (electrode/electrolyte interface and air stability) of Li-argyrodite SSEs are comprehensively presented. Finally, attractive research directions and perspectives for doped Li-argyrodite SSEs are presented, which are of great significance in guiding the energy conversion and storage of Li-argyrodite-based ASSBs.

In this study,graphdiyne was prepared using a γ-irradiated N-doping photogram to transform two-dimensional graphdiyne into a one-dimensional tubular structure for use as substrate-supported iron nanoparticles for cathodic redox reaction(ORR)in fuel cells.Methods such as scanning electron microscopy,X-ray diffraction,Raman spectroscopy,and isothermal nitrogen adsorption and other characterization methods were used to characterize and analyze the surface morphology,element composition,crystalline structure,and defect degree of the prepared composites.In the alkaline solution,the prepared catalyst was characterized by ORR performance,four-electron selectivity,kinetics and stability via cyclic voltammetry test,linear sweep voltammetry test and electrochemical AC impedance spectroscopy test.The results showed that after γ-ray irradiation,the nitrogen-doped graphite monoalkyne-loaded iron nanoparticle(NGY-Fe)catalyst had a larger specific surface area(411.3 m2/g)and a multilevel pore structure,which was conducive to the exposure of the active center.Moreover,the O2 permeation barrier was decreased,and the ORR activity of the NGY-Fe was significantly improved,especially in terms of the stability and methanol resistance,which were far superior to those of the commercially available commercial Pt/C catalysts.

Atomic-scale interface engineering is a prominent strategy to address the large volume expansions and sluggish redox kinetics for reinforcing K-storage. Here, to accelerate charge transport and lower the activation energy, dual carbon-modified interfacial regions are synthesized with high lattice-matching degree, which is formed from a CoSe2 /FeSe2 heterostructure coated onto hollow carbon fibers. State-of-the-art characterization techniques and theoretical analysis, including ex-situ soft X-ray absorption spectroscopy, synchrotron X-ray tomography, ultrasonic transmission mapping, and density functional theory, are conducted to probe local atomic structure evolution, mechanical degradation mechanisms, and ion/electron migration pathways. The results suggest that the heterostructure composed of the same crystal system and space group can sharply regulate the redox kinetics of transition metal selenium and dual carbon-modified approach can tailor physicochemical degradation. Overall, this work presents the design of a stable heterojunction synergistic superior hollow carbon substrate, inspiring a pathway of interface engineering strategy toward high-performance electrode.

The growth of lithium dendrites and the shuttle of polysulfides in lithium metal batteries (LMBs) have hindered their development. In LMBs, the cathode and anode are separated by a separator, although this does not solve the battery's issues. The use of biomass materials is widespread for modifying the separator due to their porous structure and abundant functional groups. LMBs perform more electrochemically when lithium ions are deposited uniformly and polysulfide shuttling is reduced using biomass separators. In this review, we analyze the growth of lithium dendrite and the shuttle of polysulfide in LMBs, summarize the types of biomass separator materials and the mechanisms of action (providing mechanical barriers, promoting uniform deposition of metal ions, capturing polysulfides, shielding polysulfide). The prospect of developing new separator materials from the perspective of regulating ion transport and physical sieving efficiency as well as the application of advanced technologies such as synchrotron radiation to characterize the mechanism of action of biomass separators is also proposed.

Fe2O3 is considered a potential electrode material owing to its high theoretical capacity, low cost, and non-toxic characteristics. However, the significant volume expansion and structural degradation during charging and discharging hinder its application in potassium ion batteries. The electrochemical properties of the electrode material are primarily influenced by the diffusion efficiency of ions and the mechanics of the object. From the construction of a one dimensional structure, a three-dimensional flower-like Fe2O3 with a high specific surface and low-dimensional spherical Fe2O3 were prepared. Considering the convenience and visualization of the research, micron-scale Fe2O3 was prepared, although the larger particle size will lose part of the capacity. Notably, compared with the spherical structure, the specific capacity of the flower structure was increased by about 100%. The von Mises stress distribution on the two structures was simulated by the finite element method, revealing the mechanism of electrode failure induced by volume expansion and confirming the vital role of the multidimensional system in relieving stress concentration and improving electrochemical performance. Furthermore, synchrotron radiation soft X-ray absorption spectrum and X-ray micro-tomography revealed the phase transformation process and reaction mechanism of Fe2O3 in potassium ion batteries. The dimensional structure construction strategy reported here can provide theoretical support for modifying transition metal oxides.

Some special electronic equipment not only need to avoid the interference of external electromagnetic waves (EMWs), but also need to transmit effective signals. Therefore, the development of directional electromagnetic interference (EMI) shielding materials has a great prospect. The asymmetric structure, consisting of the porous magentic rGF (reduced graphene oxide and Fe3O4) layer and the dense electrical conductivity rGM (reduced graphene oxide and MXene) layer, was constructed by dual-needle 3D printing technology. After encapsulation and curing with polydimethylsiloxane (PDMS), the rGF/rGM/PDMS composites were prepared. When the ratio of rGF and rGM layers is 6:4, the SE values of rGF-6/rGM-4/PDMS composites are 38.75 dB and 30.79 dB respectively when EMWs are incident on the rGF layer and rGM layer respectively, and the Delta SE of which is about 8 dB. The results showed that the asymmetric structure composed of porous magnetic layer and dense deeply electric conductive layer could generate a special process of "weak reflection-absorption-strong reflection-reabsorption" for incident EMW. At the same time, the simulation results of the waveguide method validated the experimental results, and further explained the directional EMI shielding mechanism of asymmetric structure. For the first time, this work designs an asymmetric structure based on the double needle 3D printing technology, which provides useful inspiration for the structural design and potential application of directional EMI shielding materials.

Nonuniform Li + flux and lithiophilic sites cause uneven lithium deposition, which impedes the application of lithium metal batteries. Herein, a reduced graphene oxide (rGO)/Ti 3 C 2 T x lattice with periodic printed holes is fabricated by 3D printing. Mesoporous structures formed by regularly assembled nanosheets provide abundant lithiophilic sites. The Li + flux is regulated by the periodic printed holes prepared by 3D printing. The deposition of lithium is homogenized by the synergistic effect of uniform Li + flux and abundant lithiophilic sites. The resultant 3D‐printed Li anode has excellent cycling stability up to 3000 h and a high average Coulombic efficiency of 98% after a long lifespan of ≈1000 h. Our work highlights the effect of the correlation between macroscopic and microscopic pores formed by 3D printing on inhibiting lithium dendrites, providing a novel pathway for highly 3D‐printed stable lithium metal anode.

Sodium-ion batteries (SIBs) have attracted significant attention as promising next-generation energy storage devices. However, the research and development of SIBs are still in their infancy due to the lack of suitable high-performance anode materials. As a commercial anode material for lithium-ion batteries (LIBs), graphite often shows a low sodium storage capacity. Herein, a graphite heterojunction material was prepared through a facile ball-milling method. During the ball-milling process, a defect-enriched g-C3N4/graphite heterojunction was formed and the nitrogen-containing functional groups were regulated, which promoted the sodium storage capacity. The resulting g-C3N4/graphite electrode can exhibit excellent long cycle stability and rate performance, delivering a high reversible capacity of 202 mAh g(-1) at 1.0 A g(-1) after 6000 cycles and 90.06 mAh g(-1) at 5.0 A g(-1) after 10000 cycles. Moreover, an ultrahigh rate capability can also be obtained at 1.0 A g(-1) with a capacity of 111 mAh The superiority of heterostructures for sodium storage and diffusion was proved via DFT calculations, which verified the synergistic effect between graphite and g-C3N4. This study provides a simple and efficient method for preparing g-C3N4/graphite heterostructures as well as a deep insight into the sodium storage mechanism of a heterostructure anode.

A 3D framework with a gradient-distributed heterojunction and fast Li+conductivity Li–Al–O interfaces promotes the rate performance in lithium metal anodes.

Sodium and potassium ion storage have received more attention over the last several years due to their fascinating properties, such as competitive cost-benefit and sustainable resource supply. It is challenging to maintain a stable electrode structure during the electrochemical process for the larger radius ions of Na+ and K+. One-dimensional (1D) materials can be an ideal model for developing insight into relationships between physical-chemical properties and dimension when used as electrodes. Furthermore, it can serve as a convenient migration pathway for electrons or ions, enhancing charge transfer and reducing contact resistance. As a controllable and facile synthesis approach, electrospun can be applied to design 1D nanofibers with tunable compositions and morphologies to supply the required high electrochemical activity and stability. In this review, we will discuss current electrospun techniques used to make stable electrodes for larger radius ions and enhance electrochemical stability. Some approaches to promote the thermal stability and mechanical strength of separators through electrospun strategies are also included. The insights presented in this article can serve as a guide for fabricating electrospun-based nanofiber electrodes for larger radius ion storage.

Hard carbon (HC) has attracted considerable attention in the application of sodium-ion battery (SIB) anodes, but the poor realistic capacity and low rate performance severely hinder their practical application. Herein we report a solvent mechanochemical protocol for the in situ fabrication of the HC-MXene/TiO2 electrode by functionalizing MXene to improve the electrochemical performance of the batteries. MXene (Ti3C2Tx) with abundant oxygen-containing functional groups reacts with HC particles in the ball milling process to form a Ti-O-C covalent cross-linked HC-MXene composite, in which the edge of the MXene nanosheets is in situ oxidized by air to form TiO2 nanorods, forming a regular 1D/2D MXene/TiO2 heterojunction structure. Ti-O-C covalent bonding can protect the heterojunction structures from pulverization and detachment from the current collector during charge/discharge cycles due to sodium-ion intercalation/detachment, thus improving the stability of the electrode structure. Meanwhile, the MXene/TiO2 heterojunction can form a 3D conductive network and provide more active sites. The resulting HC-MXene/TiO2 electrode exhibits superior electrode capacity (660 mAh g-1), making it a promising anode material for SIBs. This simple and efficient method for preparing MXene/TiO2 heterojunction-decorated HC provides a new perspective on the structural design of MXene and carbon material composites for SIBs.