Search Results (173)

Sodium-ion batteries (SIBs) have emerged as a highly promising candidate for large-scale energy storage and low-temperature (LT) applications, featuring abundant raw materials, low cost and working mechanisms analogous to lithium-ion batteries (LIBs). Although the ionic radius of Na⁺ is slightly larger than that of Li⁺, their smaller Stokes radius and lower desolvation energy barrier endow SIBs with unique thermodynamic advantages in LT environments. However, under extremely LT conditions, issues such as a sharp increase in electrolyte viscosity, sluggish desolvation kinetics, lattice distortion and detrimental phase transitions in electrode materials, as well as instability at the electrode–electrolyte interface, collectively constrain the LT electrochemical performance of SIBs. Most existing literature merely conduct fragmented and decoupled summaries focusing on a single component (electrolyte, cathode or anode), lacking systematic elucidation of the multi-factor coupled degradation mechanism under LT conditions and holistic evaluation of multi-dimensional modification strategies. To fill this research gap, this work systematically elaborates the intrinsic LT degradation mechanism of SIBs driven by multi-physical-field coupling. From four core perspectives, including electrolyte engineering, cathode modification, anode structural construction and precise interface regulation, we comprehensively summarize mainstream technical systems for LT performance enhancement at the current stage, and thoroughly analyze the working principle, technical merits and inherent limitations of various modification approaches. Finally, the future development directions of SIBs are prospected on the basis of previous research, aiming to provide systematic and scientific theoretical guidance for in-depth mechanism exploration and industrial technological upgrading of wide-temperature-range, high-performance SIBs. Full article

The commercialization of sulfide-based all-solid-state batteries (ASSBs) is severely limited by the interfacial degradation between layered oxide cathodes and sulfide solid electrolytes, resulting in electrolyte decomposition, impedance growth, and rapid capacity fading. Herein, we propose lithium dihydrogen phosphate (LiH₂PO₄, LDP) as a low-cost polyanionic interphase precursor to regulate the cathode–electrolyte interface. A uniform LDP coating was deposited onto polycrystalline NCM622 particles, producing a continuous 40-nm-thick phosphate layer. Although the LDP-coated electrode exhibited a higher initial interfacial resistance than the bare cathode, electrochemical analyses revealed a capacity retention of 94.1% after 100 cycles, compared with 73.9% for the uncoated electrode. X-ray photoelectron spectroscopy demonstrated that LiH₂PO₄ is not chemically inert toward Li₆PS₅Cl but undergoes a controlled initial reaction with sulfur-deficient species to generate a phosphate-rich artificial interphase while suppressing the unstable P–[S]_n–P species. This interphase rapidly reaches chemical equilibrium, suppressing sulfur precipitation, SO_x formation, and subsequent electrolyte decomposition. Cross-sectional STEM–EDS and focused ion beam analyses revealed that the artificial phosphate interphase inhibited elemental interdiffusion, suppressed chemical mixing, and preserved mechanical contact during prolonged cycling. These findings demonstrate that the electrochemical penalty associated with the initial formation of the LDP interphase represents the necessary cost of constructing a chemically stable interface rather than a degradation process. This study introduces a new interfacial design strategy based on chemically active sacrificial interphase precursors, providing an alternative to conventional inert oxide coatings for realizing long-term stable sulfide-based all-solid-state batteries. Full article

Mechanical scratches that penetrate the protective layers expose the steel substrate and establish a zinc–steel galvanic couple beneath an electrolyte film. This study develops a mechanism-oriented multiphysics model of scratch-width-dependent galvanic protection loss in hot-dip galvanized (HDG) steel enclosures. The model couples Butler–Volmer interfacial kinetics with equilibrium potentials related through the Nernst framework, Nernst–Planck transport of Zn²⁺, OH⁻, Na⁺, Cl⁻, and dissolved O₂, electrolyte charge conservation, reaction-derived boundary fluxes, a simplified corrosion-product deposition and transport-resistance treatment, and level-set tracking of interface evolution. Numerical field cases at scratch widths of 1, 3, and 5 mm show that widening the scratch increases the exposed-steel cathodic demand and lengthens the ionic-current path from the zinc edges to the scratch center. The resulting ohmic drop reduces the protective current and permits local iron dissolution when the center can no longer be maintained at a sufficiently negative potential. NSS morphology, cross-sectional SEM/EDS, corrosion-depth trends, and XRD observations show qualitative consistency with this mechanism. Under the investigated NSS conditions, a marked descriptive change occurs between the experimentally sampled widths of 2 and 3 mm, with 3 mm representing the first sampled condition showing pronounced protection loss. Because replicate-level corrosion-depth data and independent electrochemical measurements are unavailable, no statistical significance or quantitative model validation is claimed. Full article

Buried interfaces and interphases often govern performance loss in rechargeable batteries, although their functions are frequently inferred from spatially averaged composition, surface-sensitive measurements, or cell-level electrochemical response. In this Perspective, an interface denotes the geometrical boundary between adjacent phases, whereas an interphase denotes a finite-thickness region whose composition or structure differs from those of the adjoining bulk phases. Rather than organizing the discussion by focused ion beam (FIB) modality or battery chemistry alone, we adopt an architecture-first, evidence-bounded framework and compare three classes of buried-interface architecture: engineered particle coatings; electrochemically generated solid electrolyte interphase (SEI) and cathode–electrolyte interphase (CEI) regions together with lithium-metal deposits; and solid–solid contacts in all-solid-state batteries. For each class, the formation route and required function are related to spatial descriptors, including thickness distribution, lateral continuity, pore or gap topology, chemical gradients, contact area, and contact retention. FIB-enabled cross-sectioning, tomography, and correlative spectroscopy can register morphology, chemistry, and contact geometry within a common spatial frame, but they do not directly measure ionic conductivity, electronic leakage, adhesion energy, or local reaction rate. Such functional attribution therefore requires complementary electrochemistry, spectroscopy, modeling, temporal observation, and representative sampling. Across the three classes, durable interfacial function depends on chemically selective transport pathways that remain spatially continuous and mechanically viable during processing, cycling, and storage. Full article

Sodium-ion batteries are emerging as credible complements to lithium-ion technology for sustainable, safe, and cost-effective energy storage. This critical review links molecular-scale electrolyte solvation and interphase chemistry to electrode compatibility, full-cell engineering, manufacturing constraints, and commercial viability. Organic liquid, aqueous, ionic-liquid, concentrated, inorganic solid, polymer, and composite electrolytes are compared using transport, stability, processing, and interface criteria. The principal cathode and anode families are then evaluated in terms of practical voltage, reversible capacity, cycling stability, raw-material exposure, manufacturability, and end-of-life implications. A distinctive contribution of this work is the explicit separation of thermodynamic predictions, laboratory measurements, prototype demonstrations, and company-reported targets, together with design rules that connect electrolyte chemistry to cell-level performance. Sodium-ion batteries are unlikely to replace lithium-ion batteries universally, but they can occupy a strategic role where cost, safety, abundance, supply-chain resilience, and circularity outweigh maximum energy density. Full article

Low-temperature operation of lithium-ion batteries (LIBs) is severely limited by sluggish Li⁺ transport, aggravated interfacial polarization, and structural degradation of layered oxide cathodes. Herein, a multifunctional Li₂O-B₂O₃-Li₂SO₄ composite coating, denoted as LBLS, was constructed on LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) through a simple wet-mixing/calcination strategy. Structural and surface characterizations confirm that the LBLS-derived layer is successfully introduced onto NCM622 while the layered α-NaFeO₂ framework is well preserved. Benefiting from the regulated surface chemistry and improved interfacial kinetics, NCM622@LBLS exhibits significantly enhanced electrochemical performance, especially under subzero conditions. At −20 °C, the charge-transfer resistance decreases from 160 Ω for pristine NCM622 to 110 Ω after LBLS modification. Moreover, after 500 cycles at −20 °C, NCM622@LBLS maintains 101.57 mAh g⁻¹ with a capacity retention of 80.60%, which compares favorably with representative coated NCM622 cathodes evaluated under comparable subzero conditions. In situ XRD reveals suppressed lattice breathing, while ex situ EIS, DRT and GITT confirm reduced interfacial polarization and faster Li⁺ diffusion. Depth-profiling XPS further demonstrates that LBLS promotes an inorganic-reinforced CEI containing Li–O, B–O/B–F, and SO_x-containing species, thereby stabilizing the cathode/electrolyte interface during low-temperature cycling. Full article

Sodium-ion batteries (SIBs) are promising for large-scale energy storage owing to the abundant sodium resources, low cost, and lithium-ion battery (LIB)-analogous working principles, yet their commercialization is hindered by low energy density, insufficient cycling stability and safety concerns, which are essentially attributed to the inadequate optimization of electrolytes, electrode materials and their interfacial behaviors. This paper presents a systematic review of the latest research advances in SIBs from three core perspectives: electrolyte system optimization, electrode material design, and electrode/electrolyte interface engineering. For electrolytes, we elaborate on the optimization strategies of liquid organic, solid-state and aqueous electrolytes; for electrode materials, we summarize the research progress and modification methods of both cathode and anode materials; for interface regulation, we clarify the formation mechanisms, characterization techniques and construction strategies of the electrode/electrolyte interface. By quantitatively comparing the advantages and limitations of different technical approaches, we further propose the prioritized future research directions for SIBs in electrolyte innovation, electrode material design and interface optimization. This work aims to provide theoretical guidance and technical references for the development of high-performance SIBs by systematically sorting out the technical routes of electrolyte–electrode-interface synergy and defining the research focus of subsequent optimization. Full article

This study establishes a unified electrochemical–optical framework to elucidate adsorption-controlled charge transfer and electronic excitation at platinum–electrolyte interfaces modified by biomolecules and metal nanoparticles. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and UV-Vis absorption spectroscopy with Tauc analysis were used to probe transformations induced by vitamin B6 (pyridoxine) and silver nanoparticles (nAg) in Na₂SO₄ aqueous electrolytes. In the supporting electrolyte, platinum behaves as a blocking capacitive interface with nearly symmetric anodic–cathodic charges, high charge-transfer resistance (R_ct ≈ 3.14 kΩ·cm²), low double-layer capacitance (C_dl ≈ 4.0 × 10⁻⁵ F·cm⁻²), and deep-UV transitions (E_low ≥ 3.8 eV), confirming the electrochemical inertness of sulfate media. Vitamin B6 molecules interact with the electrode surface and modify the structure of the electrical double layer at the platinum/electrolyte interface, restructuring the double layer, increasing C_dl (≈1.2 × 10⁻⁴ F·cm⁻²), decreasing R_ct (≈0.23 kΩ·cm²), and generating irreversible surface-confined anodic processes. Tauc plots yield two transitions (E_low ≈ 2.9 eV; E_high ≈ 4.1 eV), attributed to molecular states and weak charge-transfer interactions. The results suggest electronic interactions between the silver nanoparticles and the adsorbed vitamin B6 molecules at the electrode interface. Strong electronic interactions between vitamin B6 and nAg yields ultralow R_ct (≈58 Ω·cm²), enhanced pseudocapacitance (C_dl ≈ 2.9 × 10⁻⁴ F·cm⁻²), and red-shifted transitions (E_low ≈ 2.2 eV; E_high ≈ 3.7 eV). These results show that adsorption-induced electronic coupling governs interfacial kinetics and optical excitation pathways. Full article

Tailoring electrochemically favorable architectures through polymer-assisted growth regulation offers an effective route for overcoming the structural limitations that restrict the practical performance of pseudocapacitive materials. In this study, a polyethylene glycol (PEG)-mediated interfacial modulation strategy was developed to regulate the structural evolution and electrochemical behavior of hydrothermally synthesized nickel tungstate (NiWO₄) for asymmetric supercapacitor applications. The influence of PEG concentration (0.1, 0.3, and 0.5 wt%) on crystal growth, morphology evolution, and charge-storage characteristics was systematically investigated. Structural analysis confirmed the successful formation of phase-pure monoclinic NiWO₄ without detectable impurities, while morphological studies revealed a pronounced PEG-dependent transformation in surface architecture. Among all synthesized electrodes, the optimized NiWO-P3 sample exhibited a highly interconnected porous nanograin framework with improved structural homogeneity and abundant electrochemically accessible interfaces. This favorable morphology significantly facilitated electrolyte penetration, accelerated ion transport, and enhanced redox utilization. Consequently, NiWO-P3 delivered a superior areal capacitance of 9.284 F/cm² at 10 mA/cm² and retained nearly 84% capacitance at elevated current density, demonstrating excellent rate capability. The optimized electrode further exhibited enhanced diffusion kinetics, achieving anodic and cathodic diffusion coefficients of 21.26 × 10⁻⁷ and 10.55 × 10⁻⁷ cm²/s, respectively, along with remarkable cycling durability of 85.12% after 12,000 cycles. Furthermore, the fabricated NiWO-P3//AC asymmetric supercapacitor demonstrated (ASD) promising electrochemical reversibility and prolonged operational stability, highlighting PEG-assisted interfacial engineering as an effective strategy for advancing high-performance tungstate-based energy-storage materials. Full article

All-solid-state lithium–sulfur batteries (ASSLSBs) couple the high theoretical energy density of sulfur (2600 Wh kg⁻¹) with the safety and polysulfide-shuttle suppression advantages of solid electrolytes (SEs). In practice, however, sluggish solid-state conversion kinetics, chemo-mechanical degradation in composite cathodes, and large solid–solid interfacial resistance remain the principal barriers to practical implementation. This review systematically examines recent progress across the three key components of ASSLSBs: cathodes, solid electrolytes, and interfaces. For cathodes, S/C composite design strategies and alternative active materials—including Li₂S, metal sulfides, and organosulfur compounds—are discussed. For solid electrolytes, inorganic (sulfide, oxide, halide, and hydride), polymer, and hybrid composite systems are compared. For interfaces, physical strategies (stack pressure, compliant interlayers, three-dimensional cathode architectures) and chemical strategies (cathode–SE and Li metal–SE interphase engineering, in situ stabilization) are evaluated. Outstanding challenges and design guidelines for next-generation ASSLSBs are discussed. Full article

At present, lithium lanthanum zirconate (LLZO) is regarded as one of the most promising solid-state electrolyte materials due to its high ionic conductivity (about 10⁻³ S/cm at room temperature), high chemical stability, and excellent chemical stability toward cathode materials and lithium metal anodes. However, there are several problems, such as poor interface contact with the lithium metal anode resulting in high interface impedance, a high sintering densification temperature (usually >1200 °C), a complex preparation process, and high cost. In recent years, researchers have conducted extensive studies on LLZO and achieved remarkable progress and results. This paper systematically reviews the research progress of LLZO’s structural characteristics, conductive mechanism, preparation methods, improvement strategies, and so on. Full article

The development of highly efficient and stable photoanodes is essential for advancing photoelectrochemical cathodic protection towards practical applications. Herein, a novel ternary sulfide heterojunction was engineered through the construction of a three-dimensional interlocked architecture of ZnIn₂S₄ on SnIn₄S₈ nanosheets via a sequential hydrothermal synthesis. This unique three-dimensional interlocked configuration creates an intimate interface and continuous charge transfer highways, effectively addressing the slow electron movement and poor interfacial contact that plague conventional photoelectrodes. Spectroscopic and electrochemical analyses verified the formation of a Type-II band alignment, which drives the directional migration of photogenerated electrons from ZnIn₂S₄ to SnIn₄S₈ under an intrinsic built-in electric field. Upon coupling with 304 stainless steel, the ZnIn₂S₄/SnIn₄S₃ heterojunction exhibited outstanding photoelectrochemical cathodic protection performance. It delivered impressive photocurrent densities of 15.22, 19.76, and 72.27 μA·cm⁻² in 3.5 wt% NaCl, 0.1 M Na₂S₂O₃, and 0.1 M Na₂S/NaOH electrolytes, respectively, along with a prominent 720 mV cathodic potential shift in the Na₂S/NaOH system. Most importantly, its good activity and stability in the scavenger-free 3.5 wt% NaCl solution and natural seawater highlight the strong practical potential of this 3D interlocked photoanode for sustainable marine metal corrosion control. Through a strategic multi-electrolyte assessment, the underlying protection mechanisms were decoupled, revealing that the synergy between the heterojunction-induced charge separation enabled by the three-dimensional interlocked structure and electrolyte-specific hole scavenging is key to the enhanced performance. Full article

Sodium-ion batteries (SIBs) are emerging as attractive electrochemical energy-storage systems owing to the natural abundance and low cost of sodium resources. However, their structural integrity and electrochemical stability under mechanical abuse remain insufficiently understood, particularly from the perspective of coupled morphological and transport responses in porous electrode assemblies. In this work, the material deformation behavior and electrochemical evolution of SIBs under compressional loading are systematically investigated, with particular attention to the roles of state of charge (SOC), electrode microstructure, and separator integrity. Electrochemical impedance analysis reveals that the ohmic response is mainly dominated by the extent of compressional deformation, whereas interfacial and diffusion-related resistances are jointly regulated by deformation and SOC. In particular, elevated SOC significantly intensifies the increase in diffusion impedance during compression, indicating a strong coupling between sodium-storage state and mass-transport deterioration. Moreover, cells at higher SOCs exhibit accelerated open-circuit voltage decay during extrusion, suggesting enhanced internal stress accumulation and aggravated instability of the electrode/electrolyte interface. Post-mortem morphological characterization demonstrates substantial particle fracture, pore collapse, and crack propagation in both cathode and anode materials, accompanied by severe shrinkage and partial destruction of the separator microporous network. These results establish a direct correlation between compressional deformation, microstructural damage, and electrochemical degradation in SIBs, and provide useful insights for the design of mechanically resilient electrode architectures, separator materials, and safety-oriented diagnostic strategies for next-generation sodium-ion energy-storage devices. Full article

The low-pressure environment at aircraft cruising altitudes severely degrades lithium battery performance, yet the effectiveness and mechanisms of air-cooling thermal management under such conditions remain poorly understood. This study systematically investigates the coupled thermal, electrical, and material responses of NCM523/graphite ternary batteries under forced air-cooling at three pressures (96 kPa, 77 kPa, 58 kPa) and varying wind speeds (0–10 m/s) during 4C charge/6C discharge cycling. Air cooling reduces the maximum surface temperature by up to 14.2 °C and maintains the temperature difference below 5 °C, even at 58 kPa. An optimal wind speed of 6 m/s extends cycle life by 71% at 58 kPa (from 45 to 77 cycles), suppresses resistance growth, and preserves discharge capacity. Further increasing the wind speed paradoxically accelerates degradation. Post-mortem analyses reveal that appropriate air cooling mitigates cathode particle fragmentation, restores cation mixing (I₀₀₃/I₁₀₄ from 1.07 to 1.63 for 58 kPa), reduces transition metal dissolution, and suppresses solid electrolyte interface (SEI) thickening. This work establishes an optimum air velocity for low-pressure battery cooling and provides mechanistic insights into preserving electrode structural integrity, offering design guidelines for safe battery thermal management in electric aircraft. Full article

With the growing global demand for sustainable resources, recycling spent lithium-ion batteries has become a strategic priority. Conventional pyrometallurgical and hydrometallurgical methods suffer from high energy consumption, severe pollution, and structural destruction, making them unsuitable for regenerating high-nickel cathodes. In this work, spent polycrystalline high-nickel LiNi_0.9Mn_0.1O₂ cathodes were selected, and an upcycling strategy integrating acid etching, hydrothermal relithiation, short-time annealing, and simultaneous Li₄Ti₅O₁₂ (LTO) coating was developed. This process directly transformed degraded polycrystalline cathodes into single-crystal cathode materials with excellent structural stability and electrochemical performance. During regeneration, lithium compensation and lattice recrystallization effectively repaired lithium loss, reduced Li/Ni cation mixing, reactivated the degraded structure, and reconstructed a highly ordered layered single-crystal framework. The LTO coating further stabilized the cathode/electrolyte interface, suppressed side reactions, alleviated volume strain, and promoted Li⁺ transport kinetics. Electrochemical measurements showed that the regenerated single-crystal cathode exhibited superior structural integrity, strong resistance to crack propagation, low polarization, excellent rate capability, and long-term cycling stability. A capacity retention of 84.3% was achieved after 300 cycles at 1C, outperforming commercial polycrystalline cathodes. This strategy provides an efficient and promising route for the direct regeneration of spent high-nickel ternary cathodes. Full article