Chemistry of Materials最新文献

{"title":"Oxidation-Induced Giant Resistivity Change Associated with Structural and Electronic Reconstruction in Layered Sr3Cr2O7−δ Epitaxial Thin Films","authors":"Zhaochen Ma, Daichi Oka, Shintaro Fukuda, Daisuke Shiga, Koichi Harata, Hiroshi Kumigashira, Tomoteru Fukumura","doi":"10.1021/acs.chemmater.5c00810","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00810","url":null,"abstract":"Ruddlesden–Popper-type Sr₃Cr₂O_7−δ (001) epitaxial thin films with high crystallinity and flat surfaces are grown by pulsed laser deposition. The as-grown thin films exhibit transparent color and high resistivity, indicating the existence of a number of oxygen vacancies as well as Cr³⁺ ions. Air annealing causes a nonmonotonic variation in lattice constants and a color change to brownish due to the compensation of ordered oxygen vacancies as well as oxidation of the Cr³⁺ ions to Cr⁴⁺ ions. At the same time, the room temperature resistivity shows a large decrease exceeding 5 orders of magnitude. Synchrotron-radiation photoemission spectroscopy reveals a wider Mott gap for the Cr³⁺ ions than that for Cr⁴⁺ ions. Accordingly, the giant resistivity change is attributed to the synergistic effects of dimensionality variation in the electron conduction pathway and band-structure modulation, which depends on the Cr valence within the layered structure.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"6 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Local Structure and Surface Acidity of Overlayers Prepared by Atomic Layer Deposition of Silica on Alumina","authors":"Melis Yarar, Zixuan Chen, Diana Piankova, Matthias Becker, Alexander V. Yakimov, Christophe Copéret, Pierre Florian, Christoph R. Müller, Alexey Fedorov","doi":"10.1021/acs.chemmater.5c01832","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c01832","url":null,"abstract":"Understanding the structure of the silica–alumina interface and the reactivity of such interfacial sites in amorphous aluminosilicate (ASA) materials is essential due to their industrial utilization as solid acid catalysts. Here, we link the structure of silica layers grown on alumina by atomic layer deposition (ALD) to the acidic and catalytic properties of ASA. In particular, we study the local structure of silica overlayers as a function of the number of ALD cycles applied and reveal how the coordination environment of Al and Si sites governs the Lewis and Bro̷nsted acidity and catalytic activity using methanol dehydration as a model structure-sensitive reaction. Relying on advanced solid-state NMR characterization, including ²⁷Al{²⁹Si} dipolar heteronuclear multiple-quantum coherence (D-HMQC) and ²⁹Si{²⁷Al} dipolar-mediated refocused insensitive nuclei enhanced by polarization transfer (D-RINEPT) experiments, dynamic nuclear polarization surface-enhanced NMR spectroscopy (DNP SENS), and infrared spectroscopy using probe molecules (CO, pyridine), we demonstrate that the atomic-scale mixing of silica and alumina generates strong Bro̷nsted acidity and increases the strength of the Lewis acid sites. Our findings indicate that the density of acid sites is closely related to the coverage of the alumina surface by silica and can be controlled by the number of ALD cycles applied. This study advances our understanding of the relationship between the local environment of Si and Al sites, the abundance and strength of acid sites, and the superior high-temperature selectivity of SiO_<i>x</i>-Al₂O₃-based catalysts in methanol dehydration when compared to unmodified alumina.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"32 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase Stability and Transformations in Lead Mixed Halide Perovskites from Machine Learning Force Fields","authors":"Xia Liang, Johan Klarbring, Aron Walsh","doi":"10.1021/acs.chemmater.5c01730","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c01730","url":null,"abstract":"Lead halide perovskites (APbX₃) offer tunable optoelectronic properties, but feature an intricate phase stability landscape. Here, we employ on-the-fly data collection and an equivariant message-passing neural network potential to perform large-scale molecular dynamics of three prototypical lead mixed-halide perovskite systems: CsPbX₃, MAPbX₃, and FAPbX₃. Integrating these simulations with the <span>PDynA</span> structure analysis toolkit, we resolve both equilibrium phase diagrams and the dynamic structural evolution under varying temperatures and halide mixtures. Our findings reveal that A-site cations strongly modulate tilt modes and phase pathways: MA⁺ effectively “forbids” the β-to-γ transition in MAPbX₃ by requiring extensive molecular rearrangements and crystal rotation, whereas the debated low-temperature phase in FAPbX₃ is predicted to be best represented as an <i>Im</i>3̅ (<i>a</i>⁺<i>a</i>⁺<i>a</i>⁺) cubic phase. Additionally, small changes in halide composition and arrangement, from uniform mixing to partial segregation, alter octahedral tilt correlations. Segregated domains can even foster anomalous tilting modes that impede uniform phase transformations. These results highlight the multiscale interplay between the cation environment and halide distribution, offering a route for tuning perovskite architectures toward improved phase stability and control.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"3 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailoring the Optoelectronic Properties of Benzylammonium PbI4 Hybrid Perovskites","authors":"Hamida Gouadria, Fernando Aguilar-Galindo, Michael J. Spilsbury, Rafael Cano, Juan José de Miguel, Alberto Fraile, José Alemán, Jesús Álvarez-Alonso, Sergio Díaz-Tendero, María José Capitán","doi":"10.1021/acs.chemmater.5c01152","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c01152","url":null,"abstract":"We present a joint theoretical–experimental study of perovskites formed by benzylammonium derivatives and PbI₄. The materials were synthesized with a slow evaporation method and subsequently characterized by combining three experimental techniques: X-ray diffraction, X-ray photoemission spectroscopy, and ultraviolet photoemission spectroscopy. Changes in the electronic structure in response to stimulation with visible light were also studied. Simulations were carried out within the framework of density functional theory. In the structural characterization, we have seen that these are layered materials showing alternating organic and inorganic planes with stoichiometry of (XBA)₂PbI₄, where XBA is a benzylammonium derivative. The ammonium salt varies from one perovskite to another, considering several functional groups in the <i>para</i> position of the benzylamine ring (<i>X</i> = −H, −CH₃, −OCH₃, and −CF₃). We have observed shifts in the Pb 4f, I 3d, C 1s, and N 1s photoemission spectra near the Fermi level, which allow to identify changes in the electronic structure of the perovskites with different organic parts. We attribute such observed changes to the nature of the functional group, in particular, to the permanent dipole exerted by the benzylammonium derivative, and therefore, we conclude that the optoelectronic properties of hybrid perovskites can be modified on demand by altering the electron-withdrawing nature of the organic substituent. Furthermore, the layered structure, separation of charges over long distances (large interplanar distance), and semiconducting properties make it a material in which two-dimensional electron confinement effects are expected to appear after photoexcitation, thus exhibiting a large transient photocurrent effect under visible light illumination and making it an optimal material for optoelectronic devices.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"8 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Air-Stable Short-Wave Infrared Tin Telluride and Tin Telluride/Zinc Telluride Core–Shell Colloidal Quantum Dots","authors":"Barbara Y. Martin, Hui Qian, Tyler Davidson-Hall, Nathan Yee, Xiaohua Wu, Oltion Kodra, Patricia Grinberg, Brad Methven, Ovi Mihai, Neil Graddage, Jianping Lu, Jianfu Ding, Jianying Ouyang","doi":"10.1021/acs.chemmater.5c01697","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c01697","url":null,"abstract":"To date, colloidal quantum dots (CQDs) with absorption in the short-wave infrared region (SWIR, 1–2.6 μm) typically consist of hazardous cadmium, lead, or mercury chalcogenides, which limit commercial acceptance. Environmentally friendly alternatives are therefore required to ensure minimal damage to ecosystems during fabrication, use, and disposal. A promising hazardous-element-free SWIR absorbing nanomaterial candidate is tin chalcogenide. We have developed tin telluride (SnTe) CQDs, with a size ranging from ∼17 to 26 nm and corresponding absorption peak from ∼2.3 to 2.5 μm, indicative of size-dependent quantum confinement. Air-stable tin salts (tin chloride or tin acetate) were employed instead of the typical air-sensitive bis(bis(trimethylsilyl)amino tin(II). The synthesis was systematically investigated by optimizing the ligand type (1-dodecanethiol was used to replace oleic acid to prevent oxidation), injection method, growth temperature, reaction time, and feed molar ratio between tin and tellurium precursors. To improve stability in air, a ZnTe shell was successfully synthesized via cation exchange reaction at 70 °C with zinc acetate. The SnTe/ZnTe core–shell nanocrystals were fully characterized, revealing the formation of a protective ZnTe shell with a thickness of two to three monolayers, resulting in long-term stability in air (up to 1 month). These air-stable CQDs may offer a low-toxicity alternative nanomaterial for low-cost solution-processable fabrication of SWIR optoelectronics.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"3 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering the Structure of PM6-Type Conjugated Polymer Aggregates in Solution and Film","authors":"Thomas P. Chaney, Christine LaPorte Mahajan, Masoud Ghasemi, Andrew J. Levin, Keith P. White, Scott T. Milner, Enrique D. Gomez, Michael F. Toney","doi":"10.1021/acs.chemmater.5c01540","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c01540","url":null,"abstract":"The morphology of conjugated polymer films is highly tunable, influencing their performance in organic electronics. Specifically, the molecular packing or crystal structure strongly influences electronic processes such as light absorption and charge transfer. However, the unit cells of high-performance electron donor polymers remain unknown, limiting our understanding of how processing affects structure and device performance. This study characterizes the aggregate structure of PM6-type push–pull polymers by using X-ray scattering, cryogenic electron microscopy, and molecular dynamics (MD) simulations. A forward simulation approach linking grazing-incidence wide-angle X-ray scattering (GIWAXS) with MD resolves a monoclinic unit cell that accurately describes PM6-type polymer aggregates in both thin films and casting solutions. Intimate π–π stacking between the donor and acceptor units emerges from this unit cell. Analysis of experimental GIWAXS using this unit cell quantifies sliding disorder in these aggregates, which may impact device performance. The shape and internal structure of the solution aggregates are also identified in chlorobenzene. These findings enhance our understanding of PM6-type polymer packing and outline a strategy for elucidating the crystal structures of weakly ordered materials. We expect that these results will provide future opportunities to control optoelectronic performance through aggregate formation in PM6 and other push–pull conjugated polymers.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"34 1 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Form of Yttrium in Nanocrystalline Fluorapatite from Marine Sediments at 0.11 Å Resolution","authors":"Alain Manceau, Yan Li, Andrea Giacomelli, Anne-Claire Gaillot, Jianlin Liao, Valérie Magnin, Lorenzo Spadini, Yinan Deng, Andrea Koschinsky, Olivier Mathon, Stephan N. Steinmann","doi":"10.1021/acs.chemmater.5c01722","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c01722","url":null,"abstract":"Deep-sea mud is rich in rare earth elements and yttrium (REY), with yttrium (Y) exhibiting the highest concentration. REY are found in authigenic (a-CFA) and biogenic (b-CFA) carbonate fluorapatite (CFA, Ca₅(CO₃)_<i>x</i>(PO₄)_3–<i>x</i>F_1+<i>x</i>). The presence of REY in both CFA types suggests different enrichment processes in abyssal environments, which may be traced through detailed structural analysis of REY’s coordination chemistry. The bonding environment of Y in CFA was investigated in 2018 and 2023 using extended X-ray absorption fine structure (EXAFS) spectroscopy at a resolution of 0.15 Å. While these studies offered valuable insights into Y’s short-range order, they also presented inconsistencies. Moreover, a resolution of 0.15 Å is insufficient to uncover the intricate local structure of Y in CFA. Here, we present EXAFS data at a resolution of 0.11 Å for Y in a-CFA and b-CFA collected several meters beneath the Pacific Ocean seafloor. Y is predominantly hydrated and bound to Ca and PO₄ in an amorphous phase surrounding the a-CFA and b-CFA nanocrystals and is secondarily incorporated into the crystal structure of a-CFA. There is no EXAFS evidence indicating the presence of polynuclear Y precipitate, which contrasts with a recent finding on cerium (Ce), nor supporting the formation of a Y-carbonate complex. The latter two findings are backed by density functional theory, which indicates that Y–Y pair formation is thermodynamically unfavorable and that the predicted Y–C distance is inconsistent with the EXAFS distances. This research highlights the geochemical enrichment of Y in abyssal sediments through the formation of a hydrated yttrium–calcium phosphate phase in a-CFA and b-CFA and Y for Ca substitution in authigenic a-CFA nanocrystals during the coprecipitation of calcium and phosphate.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"94 1 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Sustained Oxygen- and Nitric Oxide-Producing Hydrogel Accelerates Methicillin-Resistant Staphylococcus aureus-Infected Diabetic Wound Healing under Hypoxia","authors":"Que Bai, Fangfang Hu, Qian Gao, Caiyun Zheng, Yanni Zhang, S. Ramakrishna, Xianglong Wu, Tingli Lu","doi":"10.1021/acs.chemmater.5c00474","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00474","url":null,"abstract":"Chronic inflammation and hypoxia in the diabetic hyperglycemic microenvironment can lead to persistent vascular impairment, hindering tissue regeneration and exacerbating adverse outcomes. We propose a multifunctional regeneration strategy capable of simultaneously releasing oxygen (O₂) and nitric oxide (NO) to enhance immune regulation and angiogenesis, significantly accelerating wound healing. Here, a dual-dynamic-network hydrogel was designed for in situ depletion of excess reactive oxygen species (ROS) and immunomodulation to accelerate the remodeling of <i>MRSA</i>-infected diabetic wounds. The hydrogel was constructed using Schiff base and phenylborate ester bonds, with <span>l</span>-arginine-modified manganese dioxide (ACM) nanoparticles integrated into its framework. This hydrogel could respond to ROS in the diabetic microenvironment and subsequently generate oxygen and nitric oxide. Studies have shown that PDM hydrogel exhibited good biocompatibility, promoted cell migration, and facilitated endothelial cell tubular formation. Mechanistically, <i>in vitro</i> and <i>in vivo</i> analyses revealed that PDM could relieve excessive ROS levels, restore mitochondrial membrane potential, down-regulate pro-inflammatory marker CD86, up-regulate anti-inflammatory marker CD206, and promote macrophage polarization toward a reparative phenotype. In <i>MRSA</i>-infected full-thickness skin wounds, the PDM hydrogel alleviated hypoxia by decomposing endogenous H₂O₂ into O₂ (thereby reducing HIF-1α expression), modulated inflammatory responses (downregulating TNF-α and upregulating CD206), enhanced the expression of angiogenic factors VEGF and CD31, and increased collagen I deposition. These findings suggest that the multifunctional PDM hydrogel holds clinical potential for reshaping the damaged tissue microenvironment and offers an effective therapeutic strategy for chronic skin wound regeneration.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"105 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the Key Role of Rare-Earth (La Versus Nd) in Ni+-Based Layered Nickelates: Impact on Structures and Physical Properties","authors":"Hassan DahabDahab, Anthony Chiron, Elodie Tailleur, Alain Largeteau, Etienne Durand, François Weill, Vadim M. Kovrugin, Sami Vasala, Pieter Glatzel, Emmanuelle Suard, Gaston Garbarino, Pierre Rodière, Baptiste Vignolle, Alain Demourgues","doi":"10.1021/acs.chemmater.5c01003","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c01003","url":null,"abstract":"We report the synthesis of bulk RE_1–<i>x</i>A_<i>x</i>NiO₃ (RE = La, Nd; A = Sr, Ca) perovskite phases under high oxygen pressure (<i>T</i> = 900 °C, <i>P</i>_O₂ = 250 bar) and identify a solubility limit of <i>x</i> = 0.07 for phase-pure samples. This solubility limit, shared by the various RE and A combination investigated, is likely constrained by the Ni⁴⁺ content (<i>t</i>_2g⁶) whose electronic effect limits doping, regardless the size of RE and A atoms. Alkaline earth (hole) doping induces a decrease in the volume of the unit cell of RE_1–<i>x</i>A_<i>x</i>NiO₃, despite the presence of larger alkaline earth atoms, and an increase in the orthorhombic distortion in the case of RE = Nd (Nd_1–<i>x</i>A_<i>x</i>NiO₃). After topotactic reduction, RE_1–<i>x</i>Sr_<i>x</i>NiO₂ infinite-layers were obtained by mixing the perovskite phase with 2 mol CaH₂ in a tube sealed under secondary vacuum and treated at low temperature (250 °C). Thermogravimetric analysis was used to determine the oxygen stoichiometries of the compounds with accuracy. We find that while the perovskite parent compound RENiO₃ displays a high crystalline quality, regardless the nature of the rare-earth (Nd or La), marked stacking faults are present in the reduced NdNiO₂ infinite-layer, as determined by X-ray diffraction measurements using synchrotron radiation. The high-pressure diffraction experiment further demonstrates the role of pressure in attenuating the effect of these stacking faults that were also partially simulated and modeled using the FAULTS program. These defects are virtually absent for Sr²⁺ doping at 7% or when Nd is replaced by La. The occurrence of such stacking faults is confirmed by HRTEM analysis in the case of NdNiO₂. These stacking faults are more pronounced in the reduced infinite layer compositions for which the parent perovskite structure is more distorted, as measured by the departure of the Ni–O–Ni angle from 180°, establishing therefore a memory effect between the distortion of the perovskite structure and the occurrence of stacking faults after reduction. The more the perovskite structure is distorted, the greater the stacking fault rate. Finally, we report and discuss the magnetic properties, the electrical resistivity, and the specific heat of La and Nd-based infinite layer compositions with respect to their structural properties. More specifically, we shed light on the contribution of f-electrons of Nd³⁺ to the specific heat and discuss the possible signature of spin glass state in LaNiO₂ through magnetic and specific heat measurements.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"19 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145153693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Synthesis Conditions and Carbon Source on the Voltage Polarization Growth of Lithium Manganese Iron Phosphate","authors":"Assylzat Aishova, Michel Johnson, Libin Zhang, Nafiseh Zaker, Babak Shalchi Amirkhiz, J. R. Dahn, Michael Metzger","doi":"10.1021/acs.chemmater.5c00960","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00960","url":null,"abstract":"A high-performance LiMn_0.8Fe_0.2PO₄ (LMFP82)-positive electrode material is prepared using a simple surfactant-assisted synthesis method. Polyvinylpyrrolidone (PVP) is used as a surfactant and carbon source that leads to a thin and uniform carbon coating on the surface of nanosized LMPF82 primary particles. The synthesis parameters were varied systematically to clarify the effects of carbon content and calcination temperature on the electrochemical performance of these LMFP82 materials. The best performing LMFP82 sample, made with 20 wt % initial PVP content and calcined at 700 °C, showed a high initial discharge capacity of 155 mAh g^–1 at 0.05C to 4.2 V, impressive rate performance with 142 mAh g^–1 at 5C and 30 °C, high cycling stability with no capacity fade after 100 cycles at 0.2C, and low voltage polarization that remains stable over cycling. This study shows that the amount of carbon precursor impacts the specific capacity but not the voltage polarization growth, when within reasonable bounds (10–30 wt %). The calcination temperature on the other hand affects both specific capacity and voltage polarization growth and needed to be carefully optimized to 700 °C for optimal performance.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"19 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}