Lithium-rich manganese oxides (LRMOs) show great promise as high capacity, cost effective cathodes for next-generation Li-ion batteries, Nevertheless, they still confront issues such as voltage decline, capacity loss, and structural instability. Recent breakthroughs in situ/operando characterization methods have emerged as highly effective means for uncovering the dynamic changes in structure and electrochemical activity of these materials. This review delves into advanced methodologies enabling the real time observation of phase alterations, oxygen redox interactions, and the migration of transition metals (TMs) throughout the battery's charge/discharge cycles. By combining various characterization tools, researchers can reveal crucial connections between defect formation, redox mechanisms, and the stability of the battery's structure, enabling the development of novel approaches to suppress performance degradation. The study illustrates that mechanistic insights into phase transitions and failure modes, gained through advanced characterization, are instrumental in improving LRMOs. Prioritizing multiscale in situ methodologies coupled with machine learning for data interpretation will be crucial for rapidly developing viable LRMOs. These advancements in real time analysis hold promise for addressing current limitations and fast tracking the market introduction of high-energy-density materials for future energy storage.

For high-performance all-solid-state lithium batteries, LiaMClb-type halide solid electrolytes offer unique advantages in high-voltage compatibility, ionic conductivity, and processability. Cation doping is the primary strategy to tailor their structure and transport properties, where dopant size and valence critically influence lattice distortion, defect chemistry, and Li+ migration. This review systematically examines the regulatory mechanisms of single-cation doping in LiaMClb electrolytes. Based on the combined effects of valence difference and radius mismatch, six doping regimes are distinguished. We analyze how each regime affects crystal structure, defect evolution, and ionic conductivity, and identify common failure modes. This work aims to provide a design rule for achieving high-conductivity and stable halide electrolytes toward practical all-solid-state lithium-ion batteries (ASSLBs).

A novel V2O5/InVO4/In2O3 dual type-II heterojunction photocatalyst was designed and evaluated for enhanced tetracycline (TC) degradation under visible light. Synthesized via an in situ solid-state reaction, this configuration utilizes InVO4 nanoparticles as molecular bridges connecting V2O5 and In2O3 phases, promoting intimate interfacial contact and significantly improving photogenerated charge separation. Band structure analysis confirmed favorable energy band alignment among the three components, facilitating effective heterojunction construction. The optimized catalyst achieved 98.9% degradation within 160 min, which is 3.14 and 1.38 times higher in degradation efficiency than pristine V2O5 and In2O3, respectively. This performance is attributed to the dual type-II charge transfer mechanism, with photogenerated holes (h+) identified as the dominant active species. Cycling experiments confirmed the catalyst retained high activity and structural stability after five consecutive cycles. This study underscores the potential of in situ synthesized ternary heterojunctions for addressing antibiotic contamination and provides new insights for solar-driven environmental remediation.

The transition metal sulfides coupled with conductive matrix make them an ideal candidate for advanced high-performance energy storage systems. In this work, a SnS:ZnS@g-C3N4 ternary composite was synthesized and systematically evaluated for dual applications in lithium-ion batteries (LIBs) and supercapacitors. Anchoring the SnS:ZnS heterostructure onto graphitic carbon nitride (g-C3N4) significantly enhances the surface area, electrical conductivity, and density of electroactive sites. Moreover, the strong interfacial synergistic interactions within the composite promote rapid charge transport, improve lithium-storage kinetics, and effectively mitigate the severe volume fluctuations typically associated with alloy-type anode materials. As an LIB anode, the optimized SnS:ZnS@g-C3N4 electrode delivers an impressive initial discharge capacity of 1576 mAh g(-1) and maintains a high reversible capacity of 1045 mAh g(-1) at 0.3 A g(-1) for 1000 cycles, outperforming previously reported electrodes. In supercapacitor applications, the SnS:ZnS@g-C3N4 electrode exhibits an excellent specific capacitance of 1606 F g(-1) at 1 A g(-1) than its pristine counterparts. The assembled asymmetric device (SnS:ZnS@g-C3N4//AC) achieves a maximum specific capacitance of 160 F g(-1) at 1 A g(-1) and delivers an energy density of 50 Wh kg(-1) at 750 W kg(-1). The combined experimental findings and Density Functional Theory (DFT) analysis corroborate the exceptional electrochemical performance of the ternary composite and underscore its strong potential as a highly efficient dual-functional electrode material. This synthetic strategy provides a promising pathway for designing next-generation multifunctional energy storage devices.

High-entropy oxides (HEOs) stabilize single-phase solid solutions from five or more cations, yet a central question of what determines which crystal structure actually forms when configurational entropy exceeds 1.5R remains unresolved. This review systematically addresses this question by comparing the formation mechanisms of the four dominant HEOs structures: rock-salt, spinel, perovskite, and fluorite. We demonstrate that entropy is a necessary but insufficient condition; phase selection is ultimately governed by four elemental intrinsic properties: valence state, ionic radius, electronegativity, and coordination preference. Critically, each structure imposes a distinct and dominant constraint. Rock-salt phases demand uniform divalent states and matched octahedral coordination. Spinel phases require selective occupancy between tetrahedral and octahedral sites. Perovskite phases rely on the tolerance factor and A-/B-site charge balance. Fluorite phases depend on tetravalent cations and charge compensation via oxygen vacancies. Beyond mechanistic insights, we establish explicit links between these formation rules and functional properties. Finally, we discuss how advanced characterization and multi-scale computational methods are influencing the field. This review provides a unified comparative framework to guide the precise prediction and on-demand synthesis of high-performance HEOs.

Severe zinc dendrite growth and parasitic side reactions significantly limit the cycling stability of aqueous zinc-ion batteries (AZIBs), hindering their practical application. Herein, we propose a rational strategy to regulate Zn deposition by engineering protective layers with distinct Zn coordination environments. By precisely tailoring the coordination states of Zn atoms, heterogeneous interfacial microenvironments are constructed, which synergistically suppress dendrite formation and the hydrogen evolution reaction (HER). Specifically, low-coordinated Zn sites enhance zincophilicity, enabling uniform Zn nucleation and deposition, while high-coordinated Zn sites weaken H adsorption and effectively inhibit HER. As a result, the Zn-0.55N2+0.45N3@Zn||Zn-0.55N2+0.45N3@Zn symmetric cell achieves an ultralong cycling lifespan of 6322 h at 1 mA cm-2. Meanwhile, the Zn-0.55N2+0.45N3@Zn||MnO₂ full cell exhibits markedly improved cycling stability and rate capability. This work establishes a clear correlation between atomic coordination environments and interfacial electrochemical behavior, offering a new design paradigm for highly reversible Zn anodes in next-generation AZIBs.

Efficient photocatalytic hydrogen evolution requires rapid photogenerated-electron extraction and favorable proton-reduction kinetics. Herein, phosphorus-doped Zn0.76Co0.24S (P-ZCoS) was integrated with Zn0.5Cd0.5S (ZCS) as a non-noble-metal cocatalyst to regulate interfacial charge transfer and Co-centered active sites. The optimized P-ZCoS/ZCS composite achieved an H2-evolution rate of 18.9 mmol g-1h-1 under visible-light irradiation, corresponding to 28.2- and 1.7-fold enhancements over pristine ZCS and Pt/ZCS, respectively, and retained comparable activity over four consecutive cycles. Spectroscopic and photoelectrochemical analyses demonstrated that P-ZCoS promotes directional electron extraction from ZCS, suppresses carrier recombination, and accelerates interfacial charge transfer and proton reduction. The measured work functions of P-ZCoS and ZCS were 5.23 and 4.53 eV, respectively, supporting the electron-accepting role of P-ZCoS. Theoretical calculations revealed that P incorporation increased the work function of ZCoS(110) from 4.90 to 5.20 eV, introduced P 3p states near the Fermi level, and induced pronounced Co 3d–S 3p–P 3p orbital coupling. Among the investigated sites on P-ZCoS, Co exhibited the hydrogen adsorption free energy closest to thermoneutrality ΔGH∗, identifying it as the predominant HER-active center. Thus, P-ZCoS simultaneously functions as an interfacial electron sink and an electronically regulated proton-reduction platform, demonstrating an effective strategy for designing earth-abundant cocatalysts.

The burgeoning demand for energy storage in extreme cold environments has accelerated global research into low-temperature battery technologies. Aqueous zinc-based batteries (AZBs) emerge as a leading contender due to their intrinsic safety, low cost, and high theoretical capacity. However, their operation under cryogenic conditions is severely hindered by electrolyte freezing, sluggish ion kinetics, increased interfacial resistance, and rampant zinc dendrite growth. This review comprehensively summarizes cutting-edge research breakthroughs from the past two years aimed at overcoming these barriers through a multifaceted strategy, covering electrolyte engineering, cathode innovation, anode stabilization, and separator modification. Key advances include the rational design of advanced electrolytes-such as liquid systems (e.g., ZnCl2-based, Zn(ClO4)2-based, ZnSO4-based), along with novel suspension and gel polymer electrolytes-that disrupt hydrogen-bond networks, optimize Zn2+ solvation/desolvation, and improve interfacial kinetics. We also highlight new inorganic and organic cathode materials with tailored structures, as well as highly active air cathodes that enhance low-temperature reaction kinetics. Additionally, modified zinc anodes and functional separators with tailored ion-transport channels are discussed. Finally, we provide a summary and forward-looking perspectives on future research directions. This comprehensive survey can serve as a valuable dataset to inform machine learning approaches, ultimately guiding the accelerated development of practical low-temperature AZBs.

In this study, urchin-shaped CuO microspheres were successfully synthesized as gas-sensing materials, and their sensing performance and practical application potential towards n-pentanol were systematically explored. The experimental results demonstrate that the prepared urchin-like CuO microsphere sensor possesses an optimal operating temperature of 175°C, which is significantly lower than that of most reported n-pentanol sensors. At this optimal temperature, the sensor exhibits an excellent sensing response to 100 ppm n-pentanol, with a response value as high as 9.2, and the response time and recovery time are as short as 45 s and 23 s, respectively, indicating rapid sensing dynamics. Notably, the sensor shows outstanding moisture resistance and stability (90%RH), it can still maintain stable response-recovery characteristics without obvious performance degradation, which effectively solves the problem of poor humidity adaptability of traditional n-pentanol sensors. Compared with the reported n-pentanol gas sensors, the urchin-like CuO microsphere sensor in this work not only has a remarkably lower operating temperature, which can greatly reduce energy consumption and realize low-energy-consumption detection, but also has excellent environmental adaptability, especially the strong tolerance to high humidity, making it more suitable for complex practical application scenarios.

CoP and anion-doped S-CoP catalysts were synthesized using metal–organic frameworks (MOFs) as templates and NaH2PO2 as the phosphorus source. Their morphology and structure were characterized by XRD, SEM, TEM, and BET, and electrochemical performance was evaluated. Anion doping enhances hydrogen evolution reaction (HER) activity. In acidic electrolyte, the overpotential (η10) decreases from 469.4 mV for CoP to 399.4 mV for S-CoP at 10 mA cm−2, indicating improved performance. This enhancement is attributed to electronic structure modulation, optimized hydrogen adsorption/desorption, and increased active site exposure with improved mass transport. These results provide insight into the design of non-noble-metal HER catalysts.

Potassium-ion batteries (PIBs) have garnered significant attention as promising alternatives to lithium-ion batteries (LIBs) due to their high energy density and abundant potassium resources. Alloy-type anodes are particularly attractive for PIBs because of their high specific capacity, suitable redox potential, and excellent electronic conductivity. However, the severe volume expansion during cycling often results in electrode pulverization, leading to poor electrochemical performance. In this work, porous carbon matrix with uniformly dispersed antimony nanoparticles (Sb@C) were synthesized via pyrolyzing Cu3(HHTP)2 (Cu-CAT) metal-organic framework (MOF) and subsequent cation exchange. The derived carbon matrix provides efficient electrolyte diffusion pathways and abundant active sites for K+ insertion/extraction, while the uniformly dispersed ultrafine Sb particles suppress agglomeration, buffer volume changes during cycling, and reduce electrode resistance. As an anode material for PIBs, Sb@C demonstrates outstanding rate capability (109.3 mAh g-1 at 5.0 A g-1) and exceptional cycling stability (125.0 mAh g-1 at 1.0 A g-1 after 1000 cycles, and 95.0 mAh g-1 at 2.0 A g-1 after 2000 cycles). The reaction kinetics and detailed electrochemical reaction mechanism were revealed by combining in-situ, ex-situ spectroscopy techniques and the postmortem analysis. These findings offer valuable insights into the rational design of novel alloy-based anodes for high-performance PIBs.

In this work, sea urchin-shaped CuO hierarchical microspheres assembled from two-dimensional nanosheets were synthesized via a facile one-step hydrothermal route for n-pentanol detection. Structural characterization studies confirmed the pure phase and porous hierarchical architecture of the as-obtained material, which possesses abundant active sites and efficient gas diffusion pathways. Gas sensing tests showed that the sensor based on sea urchin-like CuO microspheres presents a low optimal operating temperature of 175 °C, much lower than those of most previously reported n-pentanol sensors. At 175 °C, the sensor delivered a high response value of 9.2 toward 100 ppm n-pentanol, along with fast response/recovery times of 45 s and 23 s, respectively. Moreover, it maintained a stable sensing performance even under high relative humidity (90% RH), overcoming the poor humidity tolerance of conventional semiconductor gas sensors. Combined with material structure and surface chemical analysis, the enhanced sensing performance is attributed to the unique hierarchical structure and abundance of adsorbed oxygen species on the CuO surface. With the merits of low power consumption, fast response dynamics and superior environmental adaptability, the developed CuO sensor is promising for practical n-pentanol monitoring in complex atmospheric and industrial environments.

All-solid-state lithium batteries (ASSBs) utilising garnet-type solid-state electrolytes have attracted significant attention due to their exceptional safety and high energy density. However, poor interfacial contact between the rigid ceramic electrolyte and the electrodes, coupled with mismatched physicochemical properties, severely impedes Li+ transport and cycling stability. In this study, an asymmetric bilayer electrolyte composed of a polyepoxyhexane (PEO)-based polymer (soft) and ceramic pellet (hard) was developed. An in-situ polymerisation strategy enabled seamless integration between the two layers, leading to the formation of a fully compatible interface. Moreover, this asymmetric bilayer electrolyte (PP-15-LAT) delivers a high ionic conductivity of 2.92 × 10−3 S cm−1 at 60 °C together with a high Li+ transfer number of 0.72, effectively accelerating Li+ transport kinetics. Meanwhile, it also strengthens electrode/electrolyte interfacial contact and suppresses lithium dendrite growth. Accordingly, the lithium symmetric cell displays a high critical current density of 0.9 mA cm−2 and stable cycling at 0.1 mA cm−2 for 600 h. The LiFePO4|PP-15-LAT|Li cell displays an initial discharge capacity of 158.1 mAh g−1 at 0.1C, retaining 148 mAh g−1 after 200 cycles with a Coulombic efficiency approaching 100%. This asymmetric bilayer electrolyte design provides a viable strategy for the practical application of interface-stabilized ASSBs.

Severe zinc dendrite growth and parasitic side reactions significantly limit the cycling stability of aqueous zinc-ion batteries (AZIBs), hindering their practical application. Herein, we propose a rational strategy to regulate Zn deposition by engineering protective layers with distinct Zn coordination environments. By precisely tailoring the coordination states of Zn atoms, heterogeneous interfacial microenvironments are constructed, which synergistically suppress dendrite formation and the hydrogen evolution reaction (HER). Specifically, low-coordinated Zn sites enhance zincophilicity, enabling uniform Zn nucleation and deposition, while high-coordinated Zn sites weaken H adsorption and effectively inhibit HER. As a result, the Zn-0.55N2 + 0.45 N3@Zn||Zn-0.55N2 + 0.45 N3@Zn (Zn-0.55N2 + 0.45 N3 denotes ZIF-8 crystals with surface ZnN2 and ZnN3 coordination states in a ratio of 0.55:0.45) symmetric cell achieves an ultralong cycling lifespan of 6322 h at 1 mA cm−2. Meanwhile, the Zn-0.55N2 + 0.45 N3@Zn||MnO2 full cell exhibits markedly improved cycling stability and rate capability. This work establishes a clear correlation between atomic coordination environments and interfacial electrochemical behavior, offering a new design paradigm for highly reversible Zn anodes in next-generation AZIBs.

Solid-state lithium metal batteries (SSLMBs) have attracted intense attention due to their high energy density and enhanced safety. However, harmful Li dendrite growth remains a major challenge due to insufficient understanding of its underlying mechanism and lack of effective control strategies. Herein, we designed an ion/ electron-conductive dual-layer (IECDL) with lithiophobic/lithiophilic and flexible/rigid bifunctional properties to enable a uniform and reversible Li deposition in the interlayer. During Li plating/stripping, a thin LiF-rich layer in situ forms on the rigid, lithiophilic layer at the gel/LiIn interface, acting as a lithiophobic, rigid, ionconductive barrier that suppresses Li dendrite growth without disrupting the interfacial structure. The strong Li dendrite suppression capability of the IECDL is further validated by extending the interlayer compositions. Enabled by this engineered interface, the Li symmetric cell exhibits a high critical current density of 2.8 mA cm-2 and stable cycling for over 900 h at 2.0 mA cm- 2. SSLMBs paired with a LiFePO4 cathode and IECDL interlayer demonstrate an areal capacity of 2.0 mAh cm- 2 with 92.5% capacity retention after 100 cycles at 0.2 C (1 C = 170 mA g- 1). This interlayer design and synthesis strategy provides a promising pathway toward dendritesuppressed, high-energy SSLMBs for practical applications.

The in situ exsolution of catalytic particles upon reduction makes double-perovskites promising candidates for next-generation solid oxide cells (SOCs). While recent in situ S/TEM studies have -visualized this process, these investigations have primarily focused on isolated particles rather than realistic electrode architectures and the effect of exsolution on the surrounding host matrix remains largely unexplored. Herein, a quasi-in situ S/TEM approach is presented to investigate the impact of exsolution on a realistic Sr2FeMoO6-δ (SFM) electrode by decoupling the influence of electron-beam-induced artifacts. By extracting a lamella from a bulk SOC using a plasma-FIB and performing identical-location characterization utilizing EDS and 4D-STEM before and after reduction captures both the chemical segregation and intrinsic structural transformations within the electrode grains. Utilizing iDPC and radial Fourier analysis (RFA), this approach reveals that surface exsolution is coupled with substantial crystallographic reorganization within the SFM matrix, evidenced by distinct domain shrinkage and localized phase gradients along grain facets. The interconnected bulk electrode geometry promotes higher exsolution density compared to isolated powder particles, underscoring the necessity of studying realistic architectures. By linking surface exsolution to matrix modification in a realistic bulk electrode geometry, this quasi-in situ methodology provides a vital insights into the exsolution process.

TiNb2O7 (TNO) is a promising high-capacity anode material for lithium-ion batteries due to its suitable operating voltage and theoretical capacity. However, its practical application is hindered by inherently low electronic conductivity and sluggish lithium-ion diffusion kinetics. In this work, we introduce a controllable liquid-phase reduction strategy using sodium borohydride (NaBH4) to engineer oxygen vacancies on the TNO surface. By varying the NaBH4 concentration, we achieve precise modulation of oxygen vacancy density and systematically investigate its influence on electrochemical performance. It is demonstrated that an appropriate concentration of oxygen vacancies significantly enhances charge transfer and Li+ diffusion, whereas excessive vacancy introduction leads to performance degradation due to possible structural instability. The optimized sample (treated with 100 mM NaBH4) delivers a reversible capacity of 191.7 mAh g-1 after 500 cycles at 1C and maintains 113.0 mAh g-1 even at a high rate of 10C. Mechanism studies reveal that oxygen vacancies promote the formation of Ti3+ and Nb4+, which optimize the electronic structure and provide additional active sites for lithium storage. This work not only presents an effective defect-engineering approach for improving TNO performance but also highlights the importance of vacancy concentration control in designing high-rate lithium-ion battery anodes.

The development of efficient photocatalysts for pollutant degradation requires precise control of material properties through strategic modifications. This study demonstrates how cerium doping and defect engineering synergistically enhance the photocatalytic performance of V2O5 nanorods. A series of Ce-doped V2O5 (xCe-V2O5) catalysts with varying doping concentrations were synthesized via a solvothermal method followed by heat treatment. Structural analyses revealed the coexistence of local lattice expansion and average lattice contraction after Ce incorporation, indicating defect-associated non-uniform lattice distortion. Comprehensive characterization revealed that the optimized Ce doping concentration (4 at%) induces favorable defect structures, improves electrical conductivity, and effectively narrows the band gap of V2O5 nanorods. When evaluated for rhodamine B degradation under simulated solar irradiation, the 4Ce-V2O5 catalyst exhibited exceptional activity, achieving 75.4% degradation within 240 min (compared to 59.4% for pristine V2O5) with an apparent rate constant of 0.385 h−1, together with excellent cycling stability. The enhanced performance is mainly attributed to improved visible-light absorption, accelerated charge separation, and reduced charge-transfer resistance induced by moderate Ce doping and defect structure formation. These findings establish Ce-doped V2O5 as a promising visible-light photocatalyst while providing fundamental insights into defect engineering strategies for environmental remediation technologies.

Halide perovskite materials are very exciting because of their excellent optoelectronic properties and simple deposition with both solution and vapor-phase methods. Until now, solution deposition has received more attention, but there are growing indications that residual solvent may limit performance and in particular long-term stability. Evaporation is a promising alternative, but is more complicated to implement; it requires vacuum, multiple sources at different temperatures, is difficult to switch between different materials due to cross-contamination and typically leads to films with very small grain size. Here a novel contact transfer method is presented for fabricating single crystalline perovskites that maintains the simplicity and flexibility of solution deposition while avoiding the use of solvent. This contact transfer epitaxy method uses an acceptor substrate consisting of self-assembled perovskite nanocubes to control crystal orientation and a donor substrate of the desired perovskite film to determine the ultimate composition. By heating the two substrates under close contact in atmospheric conditions, the perovskite film is transferred from the donor to the acceptor substrate, showing cubic phase (100) orientation even with hexagonal donor films. It is shown that contact transfer epitaxy is compatible with a variety of compositions and does not require specialized evaporators or vacuum conditions.