Abstract Lithium iron phosphate (LiFePO4, LFP)|graphite (Gr) full cells are widely used in large-scale energy storage owing to their safety and long cycling stability. However, irreversible lithium consumption during solid electrolyte interphase (SEI) formation depletes the limited lithium inventory, causing initial capacity loss and compromising the cycling stability of full cells. Lithium-rich lithium ferrite (Li5FeO4, LFO) has emerged as a promising cathode prelithiation additive for compensating lithium loss, but its poor air stability and moisture sensitivity restrict practical application. Herein, we introduce a TiO2 interfacial coating strategy to stabilize LFO by constructing a nanoscale protective layer on particle surfaces. The TiO2 coating preserves the antifluorite structure of LFO while suppressing surface degradation and improving electrode processing compatibility. The optimized 1.5% TiO2@LFO maintains structural integrity after air exposure for 2 h and effectively mitigates slurry gelation. In LFP|Gr full cells, TiO2@LFO delivers an irreversible delithiation plateau at 3.5–4.0 V, compensating for SEI-related lithium consumption and increasing the initial discharge capacity from 160 to 175 mAh g−1. Moreover, TiO2@LFO enables stable cycling over 500 cycles at 1C, while LFP|Gr pouch cells achieve 60% capacity retention after 2000 cycles and remain capable of powering an LED lamp. This work provides an effective interfacial engineering approach for developing air-stable LFO prelithiation additives toward practical high-energy-density lithium-ion batteries.
Silicon oxide (SiOx/C) anodes are fundamentally limited by large volume variations and repeated fracture of the solid electrolyte interphase (SEI), leading to continuous electrolyte decomposition and rapid loss of lithium (Li) inventory. Herein, we introduce a lithium maleate-derived unsaturated precursor to construct a highly resilient artificial SEI (ASEI) in situ. The precursor is compatible with slurry processing and undergoes interfacial reactions during the initial cycles, forming a conformal and mechanically robust interphase. Enabled by this resilient ASEI, the SiOx/C@ASEI anode shows negligible capacity decay at 1 A gu22121, maintains stable cycling under a high areal capacity (~3.1 mAh cmu22122) for 500 cycles, and improves the cycling stability of SiOx/C@ASEI||LiNi0.8Co0.1Mn0.1O2 (NCM811) full cells. Postmortem analyses directly verified reduced electrode expansion (2.5% vs. 61.4% swelling), suppressed cracking, the formation of a thin and uniform SEI (19.2 vs. 31.4 nm), and mitigated electrolyte decomposition. By decoupling SiOx volume variation from repetitive interfacial reconstruction through a resilient ASEI, this study offers a scalable strategy for developing low-swelling SiOx-based anodes for high-energy Li-ion batteries.
Thermochemical heat storage (TCHS) is a technology that stores thermal energy through reversible chemical reactions, providing high energy density and long-term storage with minimal losses. This review highlights recent advancements in the use of salt hydrates and porous matrix composites as sorbents in TCHS systems, with a focus on their synergistic effects. It begins with an overview of heat storage systems and adsorption concepts. This discussion then addresses key challenges related to salt-hydrated and composite adsorbent materials. In practical applications, salt hydrates for thermochemical heat storage face issues such as deliquescence, agglomeration, poor kinetics, and low thermal conductivity. Consequently, this review systematically categorizes hygroscopic salts embedded in porous host matrices, including zeolite-based materials, silica gel, carbon-based composites, minerals, metalu2013organic frameworks (MOFs), and mixed-salt composites. These findings highlight that high-conductivity carbon-based materials are utilized to enhance heat transfer, and that MOFs and zeolite 13X can improve sorption performance. Composite materials are analyzed to prevent agglomeration, enhance cyclic efficiency, and increase energy density. Additionally, binary salts confined within porous matrices exhibit notable synergistic effects on overall performance. Finally, the review discusses current limitations and suggests future research directions for developing suitable materialu2013adsorbate pairs.
Metal sulfides are promising high-capacity anodes for sodium-ion batteries, but their practical deployment remains constrained by coupled multiscale instabilities, including electronic localization, heterogeneous reaction pathways, interfacial side reactions, and severe chemo-mechanical degradation. In this context, heterointerfaces are best viewed not simply as conductive contacts but as multifunctional perturbation zones that coordinate electronic, chemical, and mechanical fields throughout sodiation and desodiation. At the atomic scale, interfacial activation spans a hierarchy from rare, well-supported cases of direct electronic-state reprogramming to more prevalent but still significant effects, including charge redistribution, built-in electric fields, orbital hybridization, and defect-mediated bond softening. Rather than proposing a universal theory, this review synthesizes current evidence into an evidence-guided framework that links atomic-scale activation to reaction sequencing, dynamic multiphase-boundary stabilization, and distributed deformation. Operando characterization, multiscale simulation, and data-driven analysis are integrated into a unified evidentiary workflow, while synthesisu2013structureu2013function relationships and practical benchmarking criteriau2014including areal loading, electrolyte amount, sodium inventory, full-cell validation, and voltage hysteresisu2014are treated as essential tests of interfacial relevance. By integrating mechanistic interpretation with device-level constraints, this review clarifies when heterointerface-derived benefits are likely to be causal, transferable, and practically meaningful for sodium-storage sulfides and related conversion-type anodes.
Ti2CTx MXene presents significant fabrication challenges, including difficulties in producing freestanding films, high susceptibility to oxidation under ambient conditions, and inadequate mechanical toughness, which results in brittleness. Here, through optimization of post-etch solution selection and physical delamination, binder-free freestanding electrodes with a high electronic conductivity of 1098 Su00B7cmu22121 are fabricated. The electrode exhibits high-rate specific capacitance and excellent rate capability, along with significant electrolyte-dependent behavior. In H2SO4, surface-dominated pseudocapacitance involving protons/hydronium ions prevails, delivering a specific capacitance of 617 Fu00B7gu22121 at 2 mVu00B7su22121 and 680 Fu00B7gu22121 at 1 Au00B7gu22121, while retaining 298 Fu00B7gu22121 at 100 Au00B7gu22121. This rate capability is comparable to that of previously reported Ti2CTx and many Ti3C2Tx-based electrodes. In contrast, electric double-layer capacitance dominates in NaCl or NaOH electrolytes. A rapid proton-coupled pseudocapacitance mechanism is confirmed using in situ X-ray diffraction, which reveals a reversible interlayer expansionu2013contraction of 0.22 nm during electrochemical cycling. First-principles analysis indicates strong coupling between the oxygen terminations and H3O+, which lowers the ion migration barrier, enabling a high-rate response. These advancements in fabrication reliability, mechanistic insight, and rate capability offer a viable strategy for designing Ti2CTx-based flexible MXene electrodes with enhanced high-rate performance for high-power supercapacitors. Overall, this work provides a reproducible fabrication strategy, mechanistic insight, and competitive high-rate performance for Ti2CTx-based flexible MXene electrodes.
Abstract Amorphous oxyhalides have emerged as promising solid-state electrolytes (SSEs) owing to their structural flexibility and high ionic conductivity. However, the origins of fast Li+ transport in these disordered structures remain unclear. Here, atomistic simulations reveal the microscopic mechanisms governing Li+ diffusion in amorphous xLi2O–TaCl5 electrolytes. We identified two synergistic structural factors that control ion transport: (i) a stable, interconnected oxygen-bridged framework of Ta polyhedra, which forms continuous diffusion pathways; and (ii) reduced Li–Cl coordination, which alleviates local confinement. Together, these features enhance the connectivity of the Li+ diffusion pathways and promote correlated Li+ migration. To validate and further amplify these effects, F is substituted into the amorphous oxyhalide. The optimized composition (LTOC-8%F) exhibits enhanced structural characteristics consistent with this mechanism, and a corresponding elevated theoretical room-temperature ionic conductivity of 7.22 mS cm−1. This study reveals the origins of fast ion transport in amorphous oxyhalide SSEs and establishes a mechanism-informed design strategy.
Amorphous oxyhalides have emerged as promising solid-state electrolytes (SSEs) owing to their structural flexibility and high ionic conductivity. However, the origins of fast Li+ transport in these disordered structures remain unclear. Here, atomistic simulations reveal the microscopic mechanisms governing Li+ diffusion in amorphous xLi2O–TaCl5 electrolytes. We identified two synergistic structural factors that control ion transport: (i) a stable, interconnected oxygen-bridged framework of Ta polyhedra, which forms continuous diffusion pathways; and (ii) reduced Li–Cl coordination, which alleviates local confinement. Together, these features enhance the connectivity of the Li+ diffusion pathways and promote correlated Li+ migration. To validate and further amplify these effects, F is substituted into the amorphous oxyhalide. The optimized composition (LTOC-8%F) exhibits enhanced structural characteristics consistent with this mechanism, and a corresponding elevated theoretical room-temperature ionic conductivity of 7.22 mS cm−1. This study reveals the origins of fast ion transport in amorphous oxyhalide SSEs and establishes a mechanism-informed design strategy.
All-solid-state lithium batteries (ASSLBs) are promising for next-generation energy storage owing to their enhanced safety and potential for high energy density. However, their practical deployment is constrained by challenges such as immature manufacturing processes and the high cost of key materials. Fe-based halides (FBHs) have recently emerged as compelling candidates for addressing these issues, benefiting from their low cost, structural tunability, and inherent multifunctionality. This review highlights the unique dual function of FBHs in ASSLBs, wherein they can serve simultaneously or separately as solid-state electrolytes with acceptable ionic conductivity and as high-capacity cathodes featuring reversible redox chemistry. We first discuss the structural characteristics and cost advantages of FBHs. Subsequently, we examine their applications as solid electrolytes and as cathodes in full-cell configurations, with emphasis on their interfacial compatibility and electrochemical performance. Finally, we outline the remaining challenges and perspectives on the practical implementation of FBHs in ASSLBs. This review is expected to enable systematic understanding of the dual-function potential of FBHs and offers significant guidance for the development of low-cost, high-energy-density ASSLBs.
The development of poly(vinylidene fluoride)-based composite solid-state electrolytes is severely hindered by slow Li+ transport and unstable solid-state electrolyte interphases. This study addresses these challenges by proposing a supramolecular ligand intervention strategy using 18-crown-6 as an additive. Coordination between the large-pore crown ethers and Li+ promotes lithium bis(fluorosulfonyl)imide dissociation and increases the free Li+ concentration, thereby enhancing ion transport with a high ionic conductivity and an improved Li+ transference number. Moreover, this coordination homogenizes the Li+ flux, suppressing side reactions and dendrite formation. Consequently, the modified electrolyte significantly enhances the cycling stability of Li||Li cells up to 800 h with a reduced overpotential. Additionally, the Li||NCM811 cells delivered 84.2% capacity retention after 2500 cycles at 10C, and retained 72.5% capacity after 780 cycles even at a high cut-off voltage of 4.5 V at 5C. Structural and interfacial characterizations confirmed the formation of a dense LiF/Li3N-rich SEI layer, which enhances mechanical strength and ionic transport. This study provides a robust modification approach using supramolecular ligands to achieve high-performance solid-state lithium-metal batteries.
The practical application of lithium metal batteries is severely hindered by flammable liquid electrolytes and uncontrollable lithium dendrite growth. In this study, we propose a novel asymmetric quasi-solid-state composite electrolyte (denoted as QSCE-BPL/LPE/PDL) designed to overcome these challenges. QSCE-BPL/LPE/PDL is fabricated by evaporation-induced self-assembly of one-dimensional molecular brush BC-g-PLiSTFSI [BC = bacterial cellulose, PLiSTFSI = poly(lithium 4-styrenesulfonyl-(trifluoromethylsulfonyl) imide)] and zero-dimensional hairy nanoparticle LL-g-PEGMA [LL = Li6.4La3Zr1.4Ta0.6O12, PEGMA = poly(oligo(ethylene glycol) methyl ether methacrylate)], followed by in situ cationic ring-opening polymerization of 1,3-dioxolane. The resulting ultrathin QSCE-BPL/LPE/PDL (19 u03BCm) possesses a unique asymmetric architecture comprising a rigid layer of hairy nanoparticles to suppress dendrite penetration and a composite layer to ensure good interfacial contact with the cathode. The grafted PLiSTFSI side chains enable single Li+ conduction to reduce concentration polarization, and the PEGMA side chains promote lithium salt dissociation to accelerate Li+ transport. This design yields a three-dimensional porous network that provides continuous and fast Li+ transport pathways. The optimized electrolyte achieves a high ionic conductivity of 5.44 u00D7 10u22124 S cmu22121 and a Li+ transference number of 0.67 at room temperature. Consequently, Li/LiFePO4 cells with QSCE-BPL/LPE/PDL can operate stably for 200 cycles with a high-capacity retention of 94% at 0.5 C. This study provides a feasible molecular engineering strategy for developing high-performance and safe lithium metal batteries.
Zinc-ion batteries (ZIBs) have emerged as promising energy storage devices owing to their intrinsic safety, low cost, and environmental friendliness. However, sluggish ion transport kinetics remain a major challenge limiting their practical application. Herein, porous MnO2 was synthesized via a self-assembly-assisted hydrothermal process to facilitate ion transport. Electrochemical measurements demonstrate that porous MnO2 delivers a high specific capacity of 207 mAh gu22121 at 0.2 A gu22121 after 100 cycles, significantly outperforming Mn2O3 (85 mAh gu22121) and MnO (28 mAh gu22121). Furthermore, the chargeu2013storage mechanism of porous MnO2 was systematically investigated, revealing that the capacity is predominantly governed by the MnO2 dissolution/deposition mechanism. This work provides new insights into the rational design of high-performance manganese oxide cathodes for aqueous ZIBs.
Polymeru2013ceramic composite electrolytes hold great promise for high-performance, flexible all-solid-state lithium (Li) metal batteries. However, limited ionic conductivity and high interfacial impedance remain major obstacles to their commercial deployment. Herein, a dual-composite solid electrolyte was fabricated using a simple and innovative 3D printing approach, incorporating a polyvinylidene fluoride (PVDF)u2013Li6.4La3Zr1.4Ta0.6O12 (LLZTO) structural layer and a polyethylene oxide (PEO)u2013LLZTO interfacial modification layer. In this design, the PVDF matrix serves as a robust structural framework, while the LLZTO filler synergistically enhances ionic conductivity by promoting Li-salt dissociation and suppresses dendrite formation through improved mechanical strength, particularly at the Li-metal interface. The dense PEOu2013LLZTO layer on the opposing side ensures intimate contact with the cathode, minimizes interfacial side reactions, and optimizes interfacial electrochemical properties, thereby enabling stable and high-performance all-solid-state Li batteries. At 25u00B0C, the dual-composite solid electrolyte exhibits a high ionic conductivity of 4.87 u00D7 10u22124 Su00B7cmu22121 and a wide electrochemical stability window of 5.01 V. Leveraging this advanced electrolyte, Li||Li symmetric cells demonstrate stable Li plating and stripping for over 1200 h at 0.1 mAu00B7cmu22122 without dendrite formation or short-circuiting. Correspondingly, LiFePO4/Li full cells deliver excellent electrochemical performance, maintaining 98.2% capacity retention after 200 cycles. These results highlight that employing a dual-composite solid electrolyte is an effective strategy for mitigating interfacial challenges, thereby enabling the development of high-performance solid-state Li-metal batteries.
Amorphous oxyhalides have emerged as promising solid-state electrolytes (SSEs) owing to their structural flexibility and high ionic conductivity. However, the origins of fast Li+ transport in these disordered structures remain unclear. Here, atomistic simulations reveal the microscopic mechanisms governing Li+ diffusion in amorphous xLi2Ou2013TaCl5 electrolytes. We identified two synergistic structural factors that control ion transport: (i) a stable, interconnected oxygen-bridged framework of Ta polyhedra, which forms continuous diffusion pathways; and (ii) reduced Liu2013Cl coordination, which alleviates local confinement. Together, these features enhance the connectivity of the Li+ diffusion pathways and promote correlated Li+ migration. To validate and further amplify these effects, F is substituted into the amorphous oxyhalide. The optimized composition (LTOC-8%F) exhibits enhanced structural characteristics consistent with this mechanism, and a corresponding elevated theoretical room-temperature ionic conductivity of 7.22 mS cmu22121. This study reveals the origins of fast ion transport in amorphous oxyhalide SSEs and establishes a mechanism-informed design strategy.
Co-free Ni-rich layered oxide LiNi0.8Mn0.2O2 has garnered considerable attention due to its high energy density and low cost. However, under high-voltage operation, its practical application suffers from severe lattice oxygen release and irreversible H2 u2192 H3 transition, resulting in structural degradation and rapid capacity fading. To address this inconvenience, this study proposes a Fe/Zr codoping strategy: the incorporated Fe modulates the local transition metalu2013oxygen electronic environment and stabilizes the local oxygen coordination environment via Feu2013O interactions, while Zr4+ exerts a lattice-anchoring effect through strong Zru2013O bonding, thereby suppressing oxygen loss and detrimental phase transitions upon deep delithiation. The codoped cathode material retains a well-defined layered structure and exhibits superior electrochemical performance; it delivers a high reversible capacity of 207.06 mAh gu22121 at 0.1 C, achieves capacity retention of 81.55% after 200 cycles at 1 C, and maintains a high rate capability of 141.76 mAh gu22121 at 5 C. This study provides an effective doping strategy for stabilizing lattice oxygen and modulating charge compensation in Co-free Ni-rich cathode materials.
Developing high-performance anodes from low-cost industrial byproducts is crucial for advancing sodium-ion batteries. Herein, we report a zincu2013aluminum layered double hydroxide (ZnAl-LDH) template-induced strategy for fabricating ZnO/ZnSe heterojunctions embedded within hierarchical porous carbon derived from coal tar pitch. The LDH serves as a dual functional structural template and pore-forming agent, enabling the in situ construction of intimately coupled ZnO/ZnSeu2013C interfaces. The designed ZnO/ZnSe heterostructure offers notable advantages: the heterojunction boosts charge transfer via interfacial contact between the two active components, while the mixed O2u2212/Se2u2212 anion environment, combined with nanodispersed ZnO/ZnSe and the conductive carbon matrix, effectively enhances the reaction kinetics and mitigates volume strain. Consequently, the composite anode delivers a high reversible capacity of 637.5 mAh gu22121 at 100 mA gu22121 and retains 259.7 mAh gu22121 after 1000 cycles at 5 A gu22121. Kinetic analysis indicates that the superior rate performance is attributed to a dominant capacitive contribution (93.3% at 1.2 mV su22121). A full cell configured with an Na3V2(PO4)3 cathode demonstrates practical viability, retaining 147.5 mAh gu22121 after 100 cycles. This work highlights the effectiveness of LDH-templated synthesis in constructing advanced heterostructure anodes for efficient sodium storage.
. A theoretical p-n junction photovoltaic device design procedure is proposed. The procedure comprises optical and electrical analyses to determine the device structure, including material selection, layer dimensions, doping concentrations, and performance characterization. This procedure is complemented by designing criteria, numerical modeling, and simulation algorithms. The practical implementation, including physical fabrication and practical measurements, was performed. A cadmium sulfide/cadmium telluride heterojunction film is used for the practical implementation, and the exciton generation rate is used to determine the improvement and optimization rules. Further, a correlation of theoretical and practical results is realized based on the improvement and optimization rules. The obtained results demonstrate the functionality of the proposed procedure, which can be adapted for different device structures and materials. The findings of this study are of great interest to designers and engineers interested in correlating theoretical results with practical measurements.
Carbon-based electrocatalysts have considerable potential for application in renewable and clean energy conversion systems. Although graphitic carbons have the advantages of high conductivity and electrolyte corrosion resistance, their sp2-hybridized skeleton often leads to poor porosity and insufficient intrinsic active sites, resulting in suboptimal catalytic activity for sluggish multi-electron redox reactions. Herein, we demonstrate an efficient strategy for the activation of low-active graphitized carbon nanosheets by a thermal-driven nitrogen atom removal process. The elimination of nitrogen atoms at high temperatures facilitates the rearrangement of neighboring carbon atoms, leading to numerous carbon defects and an increased surface area, while retaining the long-range ordered graphitic structure. As a result, the as-obtained defect-enriched porous graphitized carbon nanosheets (DPGCNSs) simultaneously combine abundant highly active intrinsic defects with a high graphitization degree and numerous micro/mesopores, demonstrating low overpotential and favorable kinetics for oxygen reduction and oxygen evolution reactions. Remarkably, rechargeable Zn-air batteries with DPGCNSs catalysts demonstrate superior cycling performance, exceeding 700 cycles with no obvious voltage fading.
The oxygen evolution reaction (OER) represents the dominant kinetic bottleneck in electrochemical water splitting, thereby imposing stringent demands on the development of advanced electrocatalysts that simultaneously deliver high activity and long-term stability under industrial operating conditions for large-scale hydrogen production. Here, we report the rational design and fabrication of a hierarchical Ru-decorated NiFeB nanosheet architecture (Ru@NiFeB), constructed via sequential electrodeposition and hydrothermal processing on three-dimensional nickel foam substrate. The strategic incorporation of trace Ru species (~2 wt.%) drives pronounced electronic modulation at the heterointerface, thereby fundamentally regulating the adsorption energetics of oxygen-containing intermediates. The resulting Ru@NiFeB electrode exhibits state-of-the-art OER performance, with an overpotential of merely 235 mV at 100 mA/cm2 in 1 mol/L KOH, surpassing the activity of commercial RuO2 catalysts. Remarkably, the electrode sustains a current density of 1000 mA/cm2 for over 150 h in a concentrated 4 mol/L KOH electrolyte without discernible degradation, thereby establishing one of the most stable low-doped noble metal-based OER catalysts reported to date. This work establishes a viable pathway toward cost-effective and robust electrocatalysts for industrial alkaline water electrolysis, thereby substantially advancing the feasibility of large-scale green hydrogen production.
