关键词：
Ti 2 AlNb alloy;Diffusion bonding;Post heat treatment;Phase transformation;Mechanical properties
摘要：
Diffusion-bonded Ti2AlNb-based alloys commonly present a low strength compared with the deformed or aged ones. In this study, the post heat treatment including solution and aging treatments is proposed to optimize the microstructure, contributing to strength improvement and appropriate ductility sacrifice. An available method by the introduction of fine size (both 20-100 nm) and a high fraction (59.7% and 13.7%) of O and alpha(2) phases using both solution at 1000 degrees C for 1 h and aging at 750 degrees C for 5 h can result in excellent tensile strength (992 MPa and 858 MPa) at room temperature and 650 degrees C, respectively, which increases 5.3% and 44.5% than that of as-received sample. The aging treatment can contribute to lamellar O and alpha(2) grains precipitated from the B2 parent, which results in limited dislocation slip systems and slip spaces to resist plastic deformation. Moreover, the crack propagation and fracture surfaces are also comparatively analyzed to reveal the fracture behaviors in the samples with high and low strength. This study can provide a new method for the mechanical property optimization of the welded Ti2AlNb alloys.
摘要：
Introducing foreign elements is regarded as a promising strategy for realizing bulk doping/grain boundary (GB) coating to enhance structural/interfacial stabilities of Ni-rich cathodes. However, directionally achieving control over simultaneous bulk doping and GB coating dual-modification is difficult due to the unclear interdiffusion constant between foreign element and primary components (Ni, Co, and Mn). Herein, a novel mechanism for tungsten (W) diffusion into the interior of Ni-rich cathode has been elucidated, in which the interdiffusion coefficients between W 6+ and transition metal cations have been firstly measured. Due to the fastest interdiffusivity of W 6+ /Mn n+ ( n = 3 and 4) couple proved by incorporating thermodynamic and dynamic results, the modification discrepancy foreign W element in the multi-component Ni-rich cathode has been successfully achieved by altering Mn content. It is found that single bulk W-doping has been obtained in LiNi 0.8 Mn 0.2 O 2 cathode. Encouragingly, when Mn proportion is decreased to 10 %, Li 6 WO 6 GB coating and bulk W-doping have been achieved in LiNi 0.9 Mn 0.1 O 2 and LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathodes. Inspired by dual-modification, cyclic stabilities of W-modified LiNi 0.9 Mn 0.1 O 2 have been prominently improved. The work provides the in-depth understanding of W diffusion into Ni-rich cathodes, exploiting new approaches for engineering bulk/GB modification.
Introducing foreign elements is regarded as a promising strategy for realizing bulk doping/grain boundary (GB) coating to enhance structural/interfacial stabilities of Ni-rich cathodes. However, directionally achieving control over simultaneous bulk doping and GB coating dual-modification is difficult due to the unclear interdiffusion constant between foreign element and primary components (Ni, Co, and Mn). Herein, a novel mechanism for tungsten (W) diffusion into the interior of Ni-rich cathode has been elucidated, in which the interdiffusion coefficients between W 6+ and transition metal cations have been firstly measured. Due to the fastest interdiffusivity of W 6+ /Mn n+ ( n = 3 and 4) couple proved by incorporating thermodynamic and dynamic results, the modification discrepancy foreign W element in the multi-component Ni-rich cathode has been successfully achieved by altering Mn content. It is found that single bulk W-doping has been obtained in LiNi 0.8 Mn 0.2 O 2 cathode. Encouragingly, when Mn proportion is decreased to 10 %, Li 6 WO 6 GB coating and bulk W-doping have been achieved in LiNi 0.9 Mn 0.1 O 2 and LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathodes. Inspired by dual-modification, cyclic stabilities of W-modified LiNi 0.9 Mn 0.1 O 2 have been prominently improved. The work provides the in-depth understanding of W diffusion into Ni-rich cathodes, exploiting new approaches for engineering bulk/GB modification.
作者机构：
["Tong, Zhuoya] College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, China;[Zhu, Xiaobo"] Author to whom correspondence should be addressed.
通讯机构：
[Xiaobo Zhu] A;Author to whom correspondence should be addressed.
摘要：
The massive production and utilization of lithium-ion batteries (LIBs) has intensified concerns about raw material shortage and end-of-life battery management. The development of effective recycling/reusing strategies, especially for the valuable active positive electrode materials, has attracted much interest from both academia and industry. This study presents a comprehensive patent analysis on the recycling technologies of spent LIBs. We screened and examined 672 patent filings associated with 367 application families, covering the period from 1994 to 2024. The analysis reveals an explosive growth in patenting activity since 2020, with China and the United States leading in geographical coverage. Hydrometallurgy continues as the most patented recycling technology, followed by direct regeneration, separation, and pyrometallurgy. Key innovations focus on improving leaching efficiency, developing novel purification methods, and exploring various relithiation strategies. The study also highlights the significant involvement of both companies and academic institutions in driving innovation. Our findings provide insights into the technological landscape, identify emerging trends, and lead to the discussion of potential future developments in LIB positive electrode recycling. This analysis serves as a valuable resource for researchers, industry stakeholders, and policymakers working towards sustainable energy storage solutions and circular economy strategies in the battery sector.
作者：
Liu, D. H.;Chen, X. Z.;Sun, R.;Wu, X.;Bai, H. W.;...
期刊：
Journal of Materials Research and Technology,2025年35:7204-7214 ISSN：2238-7854
通讯作者：
Liu, X;Gao, Y
作者机构：
[Chen, X. Z.; Sun, R.; Wu, X.; Bai, H. W.; Liu, D. H.; Liu, X. C.] Changsha Univ Sci & Technol, Inst Met, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Gao, Y. H.] North Univ China, Sch Aerosp Engn, Taiyuan 030051, Peoples R China.;[Zhao, Y. F.] North Univ China, Sch Mech Engn, Taiyuan 030051, Peoples R China.
通讯机构：
[Gao, Y ] N;[Liu, X ] C;Changsha Univ Sci & Technol, Inst Met, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;North Univ China, Sch Aerosp Engn, Taiyuan 030051, Peoples R China.
关键词：
Al alloys;Microalloying;Interfacial segregation;Dispersoid;Precipitation
摘要：
Manganese (Mn) is widely recognized for its effect on modifying the size and morphology of coarse Fe-rich constituents in Al-based alloys by forming fine Mn-rich dispersoids. However, this study suggests that in a Cd-micraolloyed Al–Cu–Mn-based alloy, Mn-rich dispersoids significantly promote Cu-rich precipitation at the interface during artificial aging (AA), leading to undesirable solute consumption of Cu and potential suppression of nanoprecipitation. With the help of atomic-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) and energy dispersive spectroscopy (EDS), an interesting finding is that interfacial Cu segregation at the dispersoid/matrix interface can be assembled during natural aging (NA, approximately for ∼30 days) after quenching, consequently feeding the early-stage interfacial Cu-rich precipitation during AA. Intriguingly, the microalloying effect of Cd, as the fast diffuser, is highly possible to promotes this process, which is also simultaneously and increasingly collected by the dispersoids during AA. These findings are expected to provide new insights on microstructural architecture in multicomponent Al–Cu-based alloys, highlighting the synergistic effect between Cd microalloying and Mn-rich dispersoids.
Manganese (Mn) is widely recognized for its effect on modifying the size and morphology of coarse Fe-rich constituents in Al-based alloys by forming fine Mn-rich dispersoids. However, this study suggests that in a Cd-micraolloyed Al–Cu–Mn-based alloy, Mn-rich dispersoids significantly promote Cu-rich precipitation at the interface during artificial aging (AA), leading to undesirable solute consumption of Cu and potential suppression of nanoprecipitation. With the help of atomic-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) and energy dispersive spectroscopy (EDS), an interesting finding is that interfacial Cu segregation at the dispersoid/matrix interface can be assembled during natural aging (NA, approximately for ∼30 days) after quenching, consequently feeding the early-stage interfacial Cu-rich precipitation during AA. Intriguingly, the microalloying effect of Cd, as the fast diffuser, is highly possible to promotes this process, which is also simultaneously and increasingly collected by the dispersoids during AA. These findings are expected to provide new insights on microstructural architecture in multicomponent Al–Cu-based alloys, highlighting the synergistic effect between Cd microalloying and Mn-rich dispersoids.
期刊：
CHEMICAL SOCIETY REVIEWS,2025年54(8):3775-3818 ISSN：0306-0012
通讯作者：
Zhang, Suojiang;Zhang, HT
作者机构：
[Wei, Zewei; Zhang, Haitao; Zhang, Suojiang; Zhang, Yalin; Zhang, SJ; Yuan, Xuedi] Chinese Acad Sci, Inst Proc Engn, Beijing Key Lab Solid State Battery & Energy Stora, Beijing 100190, Peoples R China.;[Yuan, Du] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Ma, Jianmin] Tiangong Univ, Sch Chem, Tianjin 300387, Peoples R China.
通讯机构：
[Zhang, HT ; Zhang, SJ] C;Chinese Acad Sci, Inst Proc Engn, Beijing Key Lab Solid State Battery & Energy Stora, Beijing 100190, Peoples R China.
摘要：
The energy density of lithium-ion batteries (LIBs) is primarily determined by the working potential of devices and the specific capacity of cathode compounds. Carbonate-based electrolytes have received considerable attention due to their significance for advancing current cell-assembly process. However, the commercially available liquid LiPF(6) based electrolytes cannot withstand the harsh high-voltage environment and the effects of cathode, due to issues such as the undesired oxidative decomposition of ethylene carbonate (EC), the catalytic influence of dissolved transition metal ions (TMs), and the poor performance of interphases with unstable morphologies and components. Furthermore, the complex working mechanisms of high-voltage electrolytes (HVEs) are not fully understood. This review presents a comprehensive summary of the HVEs, including their physical properties, solvation structures, and interface chemistry. Specifically, chemical environment of high-voltage cathode compounds and failure mechanisms of commercial electrolytes are investigated, followed by a discussion of expected functions of HVEs. Then, screening criteria for single-component electrolytes, considering their oxidation resistance and decomposition mechanism, and screening mechanism of interphase species are explored based on their energy level positions. Next, a cross-scale evolution framework is proposed, from the solvation structure to interphase characteristics, aimed at uncovering the formulation principles and synergistic effects of HVEs. Operational mechanisms are systematically scrutinized, starting from the conventional tuning of solvation structure to the incorporation of multiple components and further to the role of entropy-driven effects, all of which will favor the understanding of formulation principles and synergistic effects. Finally, integration of advanced computational methods and mature experimental techniques is expected to foster the development of novel perspectives and promising electrolyte candidates.
摘要：
Micro-nanobubbles (MNBs), as an emerging environmental-friendly technology, have shown great potential in enhancing advanced oxidation processes for water treatment. This study innovatively integrated MNBs with a biochar-supported cobalt-iron catalyst (CoFe/BC) and persulfate (PDS) system, creating a novel synergistic approach for tetracycline (TC) degradation. The CoFe/BC+PDS+MNB system achieved 95.63% TC degradation efficiency under optimized conditions (50 mg/L catalyst, 30 mg/L TC, 400 mg/L PDS), outperforming the conventional system with half the catalyst. While CO 3 2- and HCO 3 - inhibited TC degradation, NO 3 - , H 2 PO 4 - , and humic acid showed minimal interference. Mechanistic studies revealed that singlet oxygen ( 1 O 2 ), sulfate radicals (SO 4 •- ), and hydroxyl radicals (•OH) were the primary reactive species. MNBs facilitated electron transfer between dissolved oxygen (DO) and CoFe/BC, while bubble collapse generated localized •OH hotspots. Electrostatic attraction between MNBs and CoFe/BC under acidic conditions (pH 3-6.2) improved DO conversion efficiency, while MNB stability at neutral-alkaline pH ensured sustained degradation (>91% at pH 7-9). Despite pH sensitivity, the synergistic effect maintained efficient degradation across a broad pH range. This study demonstrates the potential of MNBs integration in persulfate-based advanced oxidation processes for water treatment applications.
Micro-nanobubbles (MNBs), as an emerging environmental-friendly technology, have shown great potential in enhancing advanced oxidation processes for water treatment. This study innovatively integrated MNBs with a biochar-supported cobalt-iron catalyst (CoFe/BC) and persulfate (PDS) system, creating a novel synergistic approach for tetracycline (TC) degradation. The CoFe/BC+PDS+MNB system achieved 95.63% TC degradation efficiency under optimized conditions (50 mg/L catalyst, 30 mg/L TC, 400 mg/L PDS), outperforming the conventional system with half the catalyst. While CO 3 2- and HCO 3 - inhibited TC degradation, NO 3 - , H 2 PO 4 - , and humic acid showed minimal interference. Mechanistic studies revealed that singlet oxygen ( 1 O 2 ), sulfate radicals (SO 4 •- ), and hydroxyl radicals (•OH) were the primary reactive species. MNBs facilitated electron transfer between dissolved oxygen (DO) and CoFe/BC, while bubble collapse generated localized •OH hotspots. Electrostatic attraction between MNBs and CoFe/BC under acidic conditions (pH 3-6.2) improved DO conversion efficiency, while MNB stability at neutral-alkaline pH ensured sustained degradation (>91% at pH 7-9). Despite pH sensitivity, the synergistic effect maintained efficient degradation across a broad pH range. This study demonstrates the potential of MNBs integration in persulfate-based advanced oxidation processes for water treatment applications.
摘要：
Physical reservoir computing (RC) mimics the brain's capacity for temporal processing by mapping inputs into high-dimensional feature spaces. This biologically inspired approach offers advantages in terms of training efficiency and real-time performance. To enhance physical RC's accuracy, nonlinear and dynamic responses are essential to distinguish complex time-series input data. Here, we present a sodium-doped perovskite memristor-based RC system that capitalizes on the synergistic effects of photovoltaic and photogating to induce nonlinear and high-dimensional dynamics. By precisely controlling the sodium doping concentration, we achieve a wide range of distinct conductance states (16 levels), enabling the system to effectively process diverse temporal patterns. We demonstrate the system’s capabilities across a range of computational tasks, achieving a 92.11 % accuracy in image recognition and a low normalized root-mean-square error (NRMSE) of 0.056 in temporal Hénon map prediction. Our findings demonstrate the potential for future development of high-performance memristor-based RC systems, particularly those capable of handling complex temporal tasks.
Physical reservoir computing (RC) mimics the brain's capacity for temporal processing by mapping inputs into high-dimensional feature spaces. This biologically inspired approach offers advantages in terms of training efficiency and real-time performance. To enhance physical RC's accuracy, nonlinear and dynamic responses are essential to distinguish complex time-series input data. Here, we present a sodium-doped perovskite memristor-based RC system that capitalizes on the synergistic effects of photovoltaic and photogating to induce nonlinear and high-dimensional dynamics. By precisely controlling the sodium doping concentration, we achieve a wide range of distinct conductance states (16 levels), enabling the system to effectively process diverse temporal patterns. We demonstrate the system’s capabilities across a range of computational tasks, achieving a 92.11 % accuracy in image recognition and a low normalized root-mean-square error (NRMSE) of 0.056 in temporal Hénon map prediction. Our findings demonstrate the potential for future development of high-performance memristor-based RC systems, particularly those capable of handling complex temporal tasks.
通讯机构：
[Wu, XQ; Chou, SL ; Tan, X] W;[Yu, Y ] U;Wenzhou Univ, Inst Carbon Neutralizat Technol, Coll Chem & Mat Engn, Wenzhou 325035, Zhejiang, Peoples R China.;Wenzhou Univ Technol, Innovat Inst Carbon Neutralizat, Wenzhou Key Lab Sodium Ion Batteries, Wenzhou 325035, Zhejiang, Peoples R China.;Univ Sci & Technol China, Hefei Natl Res Ctr Phys Sci Microscale, Dept Mat Sci & Engn, CAS Key Lab Mat Energy Convers, Hefei 230026, Anhui, Peoples R China.
摘要：
The electrochemical performance of hard carbon anode for sodium-ion batteries is primarily determined by the microstructure of the materials, and the challenge lies in establishing a structure-performance relationship at the molecular level. Thus far, an understanding of the intricate relationship between the structure and performance of hard carbon remains piecemeal, with research efforts scattered across various aspects. Hence, numerous controversies have arisen in this field. Herein, we provide new insights into the structure-performance relationship in hard carbon by coupling key structural parameters based on integrating theoretical computations and experimental data. Density functional theory calculations showed that the interlayer spacing determined the diffusion behavior of sodium ions in hard carbon, while appropriate defects and curvatures secured a high-quality intercalation capacity. Inspired by these theoretical results, we successfully developed a high-performance hard carbon with optimal microstructures through in situ molecular reconfiguration of biomass via a thermodynamically driven approach, which was demonstrated as an effective strategy to rationally regulate the microstructure of hard carbon by comprehensive physical characterizations from macroscopic to atomic level. More importantly, cylindrical batteries (18 650 and 33 140 types) fabricated from industrial-scale hard carbon exhibited fabulous sodium storage behaviors with excellent wide-range temperature performance (-40 to 100 degrees C), demonstrating great potential for achieving practical sodium-ion batteries with high energy density and durability in the future.
摘要：
Solar-light-driven photocatalysis is a promising solution to remove various pollution and antibiotic. However, its performance is greatly limited by the fast recombination of photogenerated charge carriers. Here, we prepared carbon-encapsulated cerium phosphate nanocomposites (CePO 4 @C) by an in situ one-step hydrothermal synthesis strategy. The carbon layer not only receives electrons from CePO 4 facilitated by an internal electric field over Mott-Schottky heterostructures but also promotes further electron diffusion along a conductive carbon layer, resulting in fast charge transfer and a low charge recombination rate of photogenerated charge carriers. Due to its suitable characteristics, the nanocomposites demonstrated high photocatalytic efficiency (98.8 % for methyl orange and 81.2 % for tetracycline hydrochloride within 40 min). This work provides an in situ one-step synthesis approach for carbon-encapsulated semiconducting oxide nanocomposites that are promising for use as highly efficient photocatalysts in future applications.
Solar-light-driven photocatalysis is a promising solution to remove various pollution and antibiotic. However, its performance is greatly limited by the fast recombination of photogenerated charge carriers. Here, we prepared carbon-encapsulated cerium phosphate nanocomposites (CePO 4 @C) by an in situ one-step hydrothermal synthesis strategy. The carbon layer not only receives electrons from CePO 4 facilitated by an internal electric field over Mott-Schottky heterostructures but also promotes further electron diffusion along a conductive carbon layer, resulting in fast charge transfer and a low charge recombination rate of photogenerated charge carriers. Due to its suitable characteristics, the nanocomposites demonstrated high photocatalytic efficiency (98.8 % for methyl orange and 81.2 % for tetracycline hydrochloride within 40 min). This work provides an in situ one-step synthesis approach for carbon-encapsulated semiconducting oxide nanocomposites that are promising for use as highly efficient photocatalysts in future applications.
关键词：
Energy transfer;Metal-organic framework;Photocatalytic oxidation;Singlet oxygen
摘要：
Integrating energy donor and acceptor chromophores as ligands within one MOF for advanced artificial photosynthesis is of great interest but appears to be a major challenge. Herein, via a simple one-pot synthetic strategy, an energy acceptor porphyrin ligand 5,15-di( p -benzoato)porphyrin (H 2 DPBP) was successfully integrated into an energy donor 1,4-naphthalenedicarboxylic acid (H 2 NDC)-based MOF (UiO-66-NDC) to construct a mixed-ligand MOF, donated as UiO-66-NDC-H 2 DPBP. Benefiting from the ample overlap between the emission spectrum of H 2 NDC and the absorption spectrum of H 2 DPBP, an efficient energy transfer ( EnT ) process from the donor H 2 NDC to the acceptor H 2 DPBP within UiO-66-NDC-H 2 DPBP can occur and be captured by time-resolved spectroscopy. Furthermore, the singlet oxygen ( 1 O 2 ) generation efficiency of UiO-66-NDC-H 2 DPBP mediated by this EnT process as well as the EnT process from the triplet state (T 1 ) of the photosensitizer H 2 DPBP ligand to the ground state of molecular oxygen ( 3 O 2 ) upon light irradiation can be maximized via simply regulating the loading amount of H 2 DPBP, leading to boosted photocatalytic activities toward important aerobic oxidation reactions of amines and sulfides, even under sunlight and ambient air. This work explores an avenue to construct high-efficiency energy donor and acceptor-based light-harvesting systems by utilizing mixed-ligand MOFs as platforms to advanced artificial photosynthesis.
Integrating energy donor and acceptor chromophores as ligands within one MOF for advanced artificial photosynthesis is of great interest but appears to be a major challenge. Herein, via a simple one-pot synthetic strategy, an energy acceptor porphyrin ligand 5,15-di( p -benzoato)porphyrin (H 2 DPBP) was successfully integrated into an energy donor 1,4-naphthalenedicarboxylic acid (H 2 NDC)-based MOF (UiO-66-NDC) to construct a mixed-ligand MOF, donated as UiO-66-NDC-H 2 DPBP. Benefiting from the ample overlap between the emission spectrum of H 2 NDC and the absorption spectrum of H 2 DPBP, an efficient energy transfer ( EnT ) process from the donor H 2 NDC to the acceptor H 2 DPBP within UiO-66-NDC-H 2 DPBP can occur and be captured by time-resolved spectroscopy. Furthermore, the singlet oxygen ( 1 O 2 ) generation efficiency of UiO-66-NDC-H 2 DPBP mediated by this EnT process as well as the EnT process from the triplet state (T 1 ) of the photosensitizer H 2 DPBP ligand to the ground state of molecular oxygen ( 3 O 2 ) upon light irradiation can be maximized via simply regulating the loading amount of H 2 DPBP, leading to boosted photocatalytic activities toward important aerobic oxidation reactions of amines and sulfides, even under sunlight and ambient air. This work explores an avenue to construct high-efficiency energy donor and acceptor-based light-harvesting systems by utilizing mixed-ligand MOFs as platforms to advanced artificial photosynthesis.
摘要：
Understanding the relationship between deformation behaviors and mechanisms is significant for the processing and application of metastable β titanium alloys. Here we aim to investigate and evaluate the abnormal yield strength and strain softening of a Ti-15.1Mo-2.77Nb-3.1Al-0.21Si alloy at room temperature. This alloy exhibits a high yield strength of 970 MPa, followed by the continuous stress drop behavior in the entire engineering strains (or true strains of 0.018 ∼ 0.056). Digital image correlation (DIC) reveals that the flow stress drop results from local strain softening associated with a local increase in strain rate, instead of Lüders strain. The pinning between dislocations and Si atoms as well as other interstitial atoms at and near grain boundaries is mainly responsible for the high yield strength. Subsequently, dislocations originating from grain boundaries can easily slip in a planar pattern along the {110} 〈111〉 slip systems, resulting in a continuous stress drop. In addition, both the low density of dislocations within β grains and large grain size also provide favorable conditions for dislocation slip over a long distance. This study reveals the mechanisms of both high yield strength and strain softening in the metastable β Ti alloys.
Understanding the relationship between deformation behaviors and mechanisms is significant for the processing and application of metastable β titanium alloys. Here we aim to investigate and evaluate the abnormal yield strength and strain softening of a Ti-15.1Mo-2.77Nb-3.1Al-0.21Si alloy at room temperature. This alloy exhibits a high yield strength of 970 MPa, followed by the continuous stress drop behavior in the entire engineering strains (or true strains of 0.018 ∼ 0.056). Digital image correlation (DIC) reveals that the flow stress drop results from local strain softening associated with a local increase in strain rate, instead of Lüders strain. The pinning between dislocations and Si atoms as well as other interstitial atoms at and near grain boundaries is mainly responsible for the high yield strength. Subsequently, dislocations originating from grain boundaries can easily slip in a planar pattern along the {110} 〈111〉 slip systems, resulting in a continuous stress drop. In addition, both the low density of dislocations within β grains and large grain size also provide favorable conditions for dislocation slip over a long distance. This study reveals the mechanisms of both high yield strength and strain softening in the metastable β Ti alloys.
期刊：
Advanced Energy Materials,2025年:2405436 ISSN：1614-6832
通讯作者：
Sangshan Peng<&wdkj&>Guang Zeng<&wdkj&>Qing He
作者机构：
[Qianqian Cheng; Mingjie Li; Wenjing Ye; Sangshan Peng; Qing He] State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineer Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 P. R. China;[Guang Zeng] School of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410004 P. R. China;[Zutao Sheng] State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineer Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 P. R. China<&wdkj&>School of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410004 P. R. China
通讯机构：
[Sangshan Peng; Guang Zeng; Qing He] S;School of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410004 P. R. China<&wdkj&>State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineer Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 P. R. China
摘要：
Non-fluorinated polymer membranes offer a commercially feasible solution for redox flow batteries (RFBs), yet their practical applications have been hampered by inherent challenges such as chemical instability and low ionic conductivity. In this study, the development of a series of ether-bond-free poly(aryl piperidine) membranes that address these limitations by introducing enhanced disorder in polymer chain packing through supramolecular interactions with organic acids, is presented. These interactions effectively disrupt densely packed polymer chains, transforming proton-inaccessible crystalline regions into accessible amorphous ones. By eliminating chemically unstable aryl ether bonds and avoiding additional chemical modifications, these membranes exhibit remarkable long-term chemical stability. The presence of abundant interchain gaps further facilitates rapid proton-selective transport. As a result, the engineered membranes demonstrate sustained performance in vanadium RFBs, maintaining stable operation for over 1000 charge/discharge cycles, and achieving an impressive energy efficiency of 80% at a high current density of 280 mA cm − 2 . The combination of experimental data and theoretical modeling suggests that the membrane's outstanding performance arises from the interconnected and widely distributed interchain gaps, which exhibit a pore-limiting diameter of ≈8 Å. These findings offer a robust design strategy for developing chemically stable, high-performance non-fluorinated membranes for RFBs and related energy conversion devices.
关键词：
Powder bed fusion;Beta titanium;Three-point bending;Transformation-induced plasticity (TRIP);Twinning-induced plasticity (TWIP)
摘要：
Compared to other loading conditions, studies on deformation mechanisms of additive manufacturing (AM)-produced β-type Ti alloys under bending remain limited. This study investigates a metastable β-type Ti–25Nb–3Zr–3Mo–2Sn (TLM, wt.%) alloy fabricated via laser powder bed fusion (L-PBF) during in-situ three-point bending. In-situ observations using scanning electron microscopy (SEM) combined with electron backscatter diffraction (EBSD) and ex-situ transmission electron microscopy (TEM) imaging during bending provided evaluation of microstructural changes and deformation mechanisms. These mechanisms are characterized by dislocation slip, {332}<113> β deformation twin, α" phase, and ω phase formation during plastic bending stage. The {112}<111> slip system dominates in the compression zone, while the {123}<111> slip system governs in the tension zone during bending. The synergistic effect of twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) significantly enhances the ductility of L-PBF-produced TLM alloy. The deformation involves stress-induced α" and ω phases, with the latter can form within grains/twinning band and at twinning boundaries. Importantly, the presence of the interfacial twin boundary (ITB)-ω thin layers at twinning band boundaries exerts a pinning effect, restraining the outward extension of stress-induced α" phase. This mechanism suggests optimized utilization of space within twinning bands, facilitating α" nucleation and uniform growth, thereby providing insights into further enhancing ductility.
Compared to other loading conditions, studies on deformation mechanisms of additive manufacturing (AM)-produced β-type Ti alloys under bending remain limited. This study investigates a metastable β-type Ti–25Nb–3Zr–3Mo–2Sn (TLM, wt.%) alloy fabricated via laser powder bed fusion (L-PBF) during in-situ three-point bending. In-situ observations using scanning electron microscopy (SEM) combined with electron backscatter diffraction (EBSD) and ex-situ transmission electron microscopy (TEM) imaging during bending provided evaluation of microstructural changes and deformation mechanisms. These mechanisms are characterized by dislocation slip, {332}<113> β deformation twin, α" phase, and ω phase formation during plastic bending stage. The {112}<111> slip system dominates in the compression zone, while the {123}<111> slip system governs in the tension zone during bending. The synergistic effect of twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) significantly enhances the ductility of L-PBF-produced TLM alloy. The deformation involves stress-induced α" and ω phases, with the latter can form within grains/twinning band and at twinning boundaries. Importantly, the presence of the interfacial twin boundary (ITB)-ω thin layers at twinning band boundaries exerts a pinning effect, restraining the outward extension of stress-induced α" phase. This mechanism suggests optimized utilization of space within twinning bands, facilitating α" nucleation and uniform growth, thereby providing insights into further enhancing ductility.
期刊：
Advanced Energy Materials,2025年:2404933 ISSN：1614-6832
通讯作者：
Marie-Ingrid Richard<&wdkj&>Tobias Schulli
作者机构：
[Michal Ronovsky] Univ. Grenoble Alpes, CNRS, Grenoble INP, LEPMI, Saint Martin d'Hères, 38402 France;[Adrien Boulineau] Univ. Grenoble Alpes, CEA, Liten, Grenoble, 38000 France;[Xiaobo Zhu] College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410114 China;[Nikita Vostrov; Isaac Martens; Mattia Colalongo; Edoardo Zatterin; Steven Leake; Tobias Schulli] ESRF - The European Synchrotron, 71 Avenue des Martyrs, Grenoble, 38000 France;Univ. Grenoble Alpes, CEA Grenoble, IRIG, MEM, NRX, 17 rue des Martyrs, Grenoble, 38000 France
通讯机构：
[Marie-Ingrid Richard; Tobias Schulli] E;ESRF - The European Synchrotron, 71 Avenue des Martyrs, Grenoble, 38000 France<&wdkj&>Univ. Grenoble Alpes, CEA Grenoble, IRIG, MEM, NRX, 17 rue des Martyrs, Grenoble, 38000 France<&wdkj&>ESRF - The European Synchrotron, 71 Avenue des Martyrs, Grenoble, 38000 France
关键词：
high voltage cathode;Li-ion batteries;LMNO;spinel;SXDM
摘要：
AbstractThe nanoscale mechanisms of ion deintercalation in battery cathode materials remain poorly understood, especially the relationship between crystallographic defects (dislocations, small angle grain boundaries, vacancies, etc), device performance, and durability. In this work, operando scanning X‐ray diffraction microscopy (SXDM) and multi‐crystal X‐ray diffraction (MCXD) are used to investigate microstrain and lattice tilt inhomogeneities inside Li1 − x Ni0.5Mn1.5O4 cathode particles during electrochemical cycling and their influence on the material degradation. Using these techniques, microscale lattice degradation mechanisms are investigated inside single crystals, extend it to an inter‐particle scale, and correlate it with the long‐term degradation of the cathode. During cycling, a crystal lattice deformation is observed, associated with phase transitions and inherent lattice defects in the measured particle. Residual misorientations are observed in the structure even after full discharge, indicating an irreversible structural change of the lattice. However, after long‐term cycling such lattice misorientations together with active material dissolution are further exacerbated only in a subset of particles, suggesting high heterogeneity of degradation mechanisms between the cathode particles. Selective degradation of particles could be caused by varying crystal quality across the sample, highlighting the need for a deep understanding of defect microstructures to enable a more rational design of materials with enhanced durability.
摘要：
To further enhance the ablation resistance of C/C composites, solid solution ceramic Ta 0·2 Zr 0·8 C was used to replace traditional ultra-high-temperature ceramic carbides for matrix modification of C/C composites. The C/C–Ta 0.2 Zr 0·8 C–SiC composite was fabricated by a high-solid-loading slurry impregnation combined with the precursor infiltration and pyrolysis process. The comparative samples of C/C–ZrC–SiC and C/C–TaC–SiC were also prepared using these same technologies. The microstructure, flexural properties, and ablation performance of the composite were investigated. Results showed that the C/C–Ta 0.2 Zr 0·8 C–SiC exhibited excellent overall flexural properties. During the ablation test under an oxyacetylene flame with high heat flux, the ablation resistance of C/C–Ta 0.2 Zr 0·8 C–SiC improved with prolonged ablation time, reaching mass and linear ablation rates of 0.67 mg/s and 0.18 μm/s after 120 s of ablation. Compared to the C/C–ZrC–SiC and C/C–TaC–SiC, the mass ablation rate of the composite was reduced by 49.24% and 68.70%, and the linear ablation rate was reduced by 97.22% and 97.71%, respectively. The enhanced ablation resistance was primarily attributed to the formation of the Ta–Zr–O oxide layer, composed of TaZr 2·75 O 8 , ZrO 2 , and Ta 2 O 5 , on the composites surface. In the oxide layer, the Ta-rich oxides served as a binder, filling gaps in the interface. Meanwhile, the Zr-rich oxides formed the skeleton that pinned the molten liquid oxides. The combined effects of Ta-rich and Zr-rich oxides made the Ta–Zr–O oxide layer more compact and strongly bonded to the matrix.
To further enhance the ablation resistance of C/C composites, solid solution ceramic Ta 0·2 Zr 0·8 C was used to replace traditional ultra-high-temperature ceramic carbides for matrix modification of C/C composites. The C/C–Ta 0.2 Zr 0·8 C–SiC composite was fabricated by a high-solid-loading slurry impregnation combined with the precursor infiltration and pyrolysis process. The comparative samples of C/C–ZrC–SiC and C/C–TaC–SiC were also prepared using these same technologies. The microstructure, flexural properties, and ablation performance of the composite were investigated. Results showed that the C/C–Ta 0.2 Zr 0·8 C–SiC exhibited excellent overall flexural properties. During the ablation test under an oxyacetylene flame with high heat flux, the ablation resistance of C/C–Ta 0.2 Zr 0·8 C–SiC improved with prolonged ablation time, reaching mass and linear ablation rates of 0.67 mg/s and 0.18 μm/s after 120 s of ablation. Compared to the C/C–ZrC–SiC and C/C–TaC–SiC, the mass ablation rate of the composite was reduced by 49.24% and 68.70%, and the linear ablation rate was reduced by 97.22% and 97.71%, respectively. The enhanced ablation resistance was primarily attributed to the formation of the Ta–Zr–O oxide layer, composed of TaZr 2·75 O 8 , ZrO 2 , and Ta 2 O 5 , on the composites surface. In the oxide layer, the Ta-rich oxides served as a binder, filling gaps in the interface. Meanwhile, the Zr-rich oxides formed the skeleton that pinned the molten liquid oxides. The combined effects of Ta-rich and Zr-rich oxides made the Ta–Zr–O oxide layer more compact and strongly bonded to the matrix.
作者机构：
[Wang, Jiaoli; Huang, Zimo; Liu, Yexiang; Bai, Maohui; Hong, Bo] Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.;[Wang, Xuhui; Bai, Maohui] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Liu, Yexiang; Hong, Bo] Cent South Univ, Hunan Prov Key Lab Nonferrous Value Added Met, Changsha 410083, Peoples R China.
通讯机构：
[Bai, MH ] C;Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.;Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词：
Pentaerythritol acrylate;N,N-dimethylacrylamide;Cross-linking gel electrolyte;Oxidation stability;Lithium-ion batteries
摘要：
Nitrogen-containing gel electrolyte has the advantages of high safety and strong compatibility, which can improve the electrochemical performance of lithium-ion batteries (LIBs). However, its inherent issues of oxidation stability and insufficient conductivity limit its large-scale application. Here, Pentaerythritol acrylate (PETEA) is used as a cross-linking agent to build a cross-linking framework with nitrogen-containing N,N-dimethylacrylamide (PNDA) gel monomer to improve the electrochemical performance of gel electrolyte (PNDET). The three-dimensional cross-linked PNDET electrolyte has a continuous Li-ion fast conduction network (7.02 mS cm-1), and its self-supporting structure improves its mechanical strength (220.0 MPa). Meanwhile, through calculation, PNDET has a lower HOMO energy level, which increases its oxidation voltage from 4.3 to 4.5 V. In addition, the cross-linked PNDET enhances the overall thermal stability of the electrolyte, and the flame retardant properties of the nitrogen-containing skeleton are significantly improved. When the PNDET matched with Ah-class NCM811/Gr pouch cells, the capacity retention rate still remains 93.5% after 600 cycles at the temperature of 60 degrees C. However, due to its extremely poor oxidation stability and thermal stability, the capacity of pouch cells with PNDA electrolyte rapidly decreases at high voltage of 4.35 V and high temperature of 60 degrees C. The cross linking strategy provides a direction for the practical application of gel electrolyte and promotes the development of gel semi-solid battery.
摘要：
The shuttling of lithium polysulfides (LiPSs), sluggish reaction kinetics, and uncontrolled lithium deposition/stripping remain the main challenges in lithium-sulfur batteries (LSBs), which are aggravated under practical working conditions, i.e., high sulfur loading and lean electrolyte in large-capacity pouch cells. This study introduces a Ti(3)C(2)T(x) MXene@CuCo(2)O(4) (MCC) composite on a polyethylene (PE) separator to construct an ultrathin MXene@CuCo(2)O(4)/PE (MCCP) film. The MCCP functional separator can deliver superior LiPSs adsorption/catalysis capabilities via the MCC composite and regulate the Li(+) deposition through a conductive Ti(3)C(2)T(x) MXene framework, enhancing redox kinetics and cycling lifetime. When paired with sulfur/carbon (S/C) cathode and lithium metal anode, the resultant 10 Ah-level pouch cell with the ultrathin MCCP separator achieves an energy density of 417Wh kg(-1) based on the whole cell and a stable running of 100 cycles under practical operation conditions (cathode loading = 10.0 mg cm(-2), negative/positive areal capacity ratio (N/P ratio) = 2, and electrolyte/sulfur weight ratio (E/S ratio) = 2.6 µL mg(-1)). Furthermore, through a systematic evaluation of the as-prepared Li-S pouch cell, the study unveils the operational and failure mechanisms of LSBs under practical conditions. The achievement of ultrahigh energy density in such a large-capacity lithium-sulfur pouch cell will accelerate the commercialization of LSBs.
期刊：
Chemical Engineering Journal,2025年504:158517 ISSN：1385-8947
通讯作者：
Ou, X;Fu, Chaochao;Shen, JX;Bai, MH
作者机构：
[Zhang, Zhi; Zhu, Wenqi; Liao, Tong; Zhang, Dongsheng] Hunan Univ Arts & Sci, Coll Chem & Mat Engn, Hunan Prov Key Lab Water Treatment Funct Mat, Changde 415000, Peoples R China.;[Gao, Shuai; Zhang, Zhi; Ou, Xing] Cent South Univ, Engn Res Ctr Minist Educ Adv Battery Mat, Sch Met & Environm, Changsha 410083, Peoples R China.;[Guo, Haipeng] Feng Fan Co LTD, Baoding 071002, Peoples R China.;[Fu, Chaochao; Wang, Yi; Shen, Jixue; Fu, CC] Hebei Univ, Hebei Technol Innovat Ctr Lightweight New Energy V, Sch Qual & Tech Supervis, Baoding 071002, Peoples R China.;[Bai, Maohui] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
通讯机构：
[Shen, JX ; Fu, CC] H;[Bai, MH ; Ou, X ] C;Cent South Univ, Engn Res Ctr Minist Educ Adv Battery Mat, Sch Met & Environm, Changsha 410083, Peoples R China.;Hebei Univ, Hebei Technol Innovat Ctr Lightweight New Energy V, Sch Qual & Tech Supervis, Baoding 071002, Peoples R China.;Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词：
Interfacial chemistry;Elevated temperature;High-voltage;Lithium-ion pouch full cell;Multicomponent additives
摘要：
The interfacial chemistry influenced by electrolyte components, including lithium salts, solvents, and additives, has attracted significant attention for its critical role in advancing high-performance lithium-ion batteries (LIBs). However, the instability of interfacial interactions between traditional electrolytes and electrodes presents a major obstacle to achieving optimal LIB performance, especially in conditions of high temperature and cut-off voltage. This work introduces an interfacial engineering method utilizing a combination of additives − specifically, fluoroethylene carbonate, ethylene sulfate, and propane sultone (referred to as FDP) − to enhance the conventional carbonate electrolyte for applications in high-voltage and high-temperature LIBs. These additives effectively adjust the interactions between lithium ions and solvents, reducing desolvation energy, thereby decreasing gas evolution, mitigating extensive solvent decomposition, and promoting the formation of a thin, uniform, low-impedance elastic interfacial film on both the anode and cathode. Noteworthy results include a 97.3 % capacity retention at 4.4 V over 250 cycles at 45 °C in a 1.7 Ah-level single crystal LiNi0.6Co0.1Mn0.3O2 (SC-NCM613)||graphite pouch full cell incorporating FDP additives. This interfacial engineering approach facilitated by these multicomponent additives presents a highly promising and practical pathway for achieving long-lasting high-voltage and high-temperature LIBs.
The interfacial chemistry influenced by electrolyte components, including lithium salts, solvents, and additives, has attracted significant attention for its critical role in advancing high-performance lithium-ion batteries (LIBs). However, the instability of interfacial interactions between traditional electrolytes and electrodes presents a major obstacle to achieving optimal LIB performance, especially in conditions of high temperature and cut-off voltage. This work introduces an interfacial engineering method utilizing a combination of additives − specifically, fluoroethylene carbonate, ethylene sulfate, and propane sultone (referred to as FDP) − to enhance the conventional carbonate electrolyte for applications in high-voltage and high-temperature LIBs. These additives effectively adjust the interactions between lithium ions and solvents, reducing desolvation energy, thereby decreasing gas evolution, mitigating extensive solvent decomposition, and promoting the formation of a thin, uniform, low-impedance elastic interfacial film on both the anode and cathode. Noteworthy results include a 97.3 % capacity retention at 4.4 V over 250 cycles at 45 °C in a 1.7 Ah-level single crystal LiNi0.6Co0.1Mn0.3O2 (SC-NCM613)||graphite pouch full cell incorporating FDP additives. This interfacial engineering approach facilitated by these multicomponent additives presents a highly promising and practical pathway for achieving long-lasting high-voltage and high-temperature LIBs.
期刊：
Journal of Colloid and Interface Science,2025年679(Pt B):809-818 ISSN：0021-9797
通讯作者：
Zhang, Chunling;Zhang, Feifei
作者机构：
[Shao, Weide; Zhang, Jianing; Lu, Biao] Key Laboratory of Automobile Materials, Ministry of Education, School of Materials Science and Engineering, Jilin University, Changchun 130022, China;[Zheng, Aodu; Li, Guiwei; Wu, Wenzheng] School of Mechanical and Aerospace Engineering, Jilin University, Changchun, Jilin 130025, China;[Chen, Shuguang] School of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China;[Zhang, Chunling] Key Laboratory of Automobile Materials, Ministry of Education, School of Materials Science and Engineering, Jilin University, Changchun 130022, China. Electronic address: clzhang@jlu.edu.cn;[Zhang, Feifei] Key Laboratory of Automobile Materials, Ministry of Education, School of Materials Science and Engineering, Jilin University, Changchun 130022, China. Electronic address: ffzhang@jlu.edu.cn
通讯机构：
[Zhang, Feifei; Zhang, Chunling] K;Key Laboratory of Automobile Materials, Ministry of Education, School of Materials Science and Engineering, Jilin University, Changchun 130022, China. Electronic address:
关键词：
3D ordered gyroid substrate;Bubble behavior;High current decoupled hydrogen and oxygen evolution;High current water electrolysis
摘要：
The conversion of renewable energy sources with relatively large energy fluctuations into hydrogen represents a crucial aspect of energy storage. Nevertheless, the direct water electrolysis process is known to require excessive instantaneous energy consumption and high cost. Two-step alkaline water electrolysis is regarded as a secure and effective method of generating hydrogen from renewable energy sources when compared to direct water electrolysis. Here we propose a two-step alkaline water electrolysis using nickel–cobalt based hydroxide (Ni 0.9 Co 0.1 (OH) 2 ) as a redox mediator, and a high-performance bifunctional catalyst as gas evolution electrodes (GEE). The substrates for the GEE were prepared using 3D printing and then loaded with in-situ grown Ru-doped MoS 2 /NiFe-LDH hierarchical heterostructure catalysts (MS-NiFe-Ru-3D). The oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) of the MS-NiFe-Ru-3D catalyst can reach up to 500 mA cm −2 at 300 and 250 mV overpotentials, respectively. It can meet the requirement of high catalyst performance for two-step alkaline water electrolysis. The direct water electrolysis using the bifunctional MS-NiFe-Ru-3D catalyst only requires a voltage of 1.85 V at 500 mA cm −2 with minimal attenuation over 300 h. For the two-step alkaline water electrolysis using MS-NiFe-Ru-3D as bifunctional catalysts and Ni 0.9 Co 0.1 (OH) 2 as redox mediator, only 1.70 V and 0.27 V were required for HER and OER at 500 mA cm −2 , respectively. This work offers a promising avenue for the efficient conversion of renewable secondary energy sources into hydrogen.
The conversion of renewable energy sources with relatively large energy fluctuations into hydrogen represents a crucial aspect of energy storage. Nevertheless, the direct water electrolysis process is known to require excessive instantaneous energy consumption and high cost. Two-step alkaline water electrolysis is regarded as a secure and effective method of generating hydrogen from renewable energy sources when compared to direct water electrolysis. Here we propose a two-step alkaline water electrolysis using nickel–cobalt based hydroxide (Ni 0.9 Co 0.1 (OH) 2 ) as a redox mediator, and a high-performance bifunctional catalyst as gas evolution electrodes (GEE). The substrates for the GEE were prepared using 3D printing and then loaded with in-situ grown Ru-doped MoS 2 /NiFe-LDH hierarchical heterostructure catalysts (MS-NiFe-Ru-3D). The oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) of the MS-NiFe-Ru-3D catalyst can reach up to 500 mA cm −2 at 300 and 250 mV overpotentials, respectively. It can meet the requirement of high catalyst performance for two-step alkaline water electrolysis. The direct water electrolysis using the bifunctional MS-NiFe-Ru-3D catalyst only requires a voltage of 1.85 V at 500 mA cm −2 with minimal attenuation over 300 h. For the two-step alkaline water electrolysis using MS-NiFe-Ru-3D as bifunctional catalysts and Ni 0.9 Co 0.1 (OH) 2 as redox mediator, only 1.70 V and 0.27 V were required for HER and OER at 500 mA cm −2 , respectively. This work offers a promising avenue for the efficient conversion of renewable secondary energy sources into hydrogen.
作者机构：
[Wenjie Peng; Huajun Guo; Junchao Zheng; Guochun Yan; Hui Duan; Xing Ou; Yucen Yan; Zhixing Wang; Zilan Zhao; Jiexi Wang; Junjie Wang; Wang, Jiexi] Cent South Univ, Sch Met & Environm, Natl Energy Met Resources & New Mat Key Lab, Engn Res Ctr,Minist Educ Adv Battery Mat,Hunan Pro, Changsha 410083, Peoples R China.;[Jiayi Li] Univ Washington, Dept Chem, Seattle, WA 98195 USA.;[Duo Deng; Wenjie Peng; Zhixing Wang; Gui Luo] BASF Shanshan Battery Mat Co LTD, Res Inst, Changsha 410205, Peoples R China.;[Wenjie Peng; Huajun Guo; Guochun Yan; Hui Duan; Mingxia Dong; Wang, Jiexi] Natl Engn Res Ctr Anvanced Energy Storage Mat, Changsha 410205, Peoples R China.;[Lingjun Li] Changsha Univ Sci & Technol, Sch Mat Sci & Engn, Changsha 410114, Peoples R China.
通讯机构：
[Wang, JX ] C;Cent South Univ, Sch Met & Environm, Natl Energy Met Resources & New Mat Key Lab, Engn Res Ctr,Minist Educ Adv Battery Mat,Hunan Pro, Changsha 410083, Peoples R China.
关键词：
Lithium ion battery;LiNiO 2;Tungsten doping;Grain boundary phase;H2↔H3 phase transition
摘要：
LiNiO 2 (LNO) is one of the most promising cathode materials for lithium-ion batteries. Tungsten element in enhancing the stability of LNO has been researched extensively. However, the understanding of the specific doping process and existing form of W are still not perfect. This study proposes a lithium-induced grain boundary phase W doping mechanism. The results demonstrate that the introduced W atoms first react with the lithium source to generate a Li–W–O phase at the grain boundary of primary particles. With the increase of lithium ratio, W atoms gradually diffuse from the grain boundary phase to the interior layered structure to achieve W doping. The feasibility of grain boundary phase doping is verified by first principles calculation. Furthermore, it is found that the Li 2 WO 4 grain boundary phase is an excellent lithium ion conductor, which can protect the cathode surface and improve the rate performance. The doped W can alleviate the harmful H2↔H3 phase transition, thereby inhibiting the generation of microcracks, and improving the electrochemical performance. Consequently, the 0.3 wt% W-doped sample provides a significant improved capacity retention of 88.5 % compared with the pristine LNO (80.7 %) after 100 cycles at 2.8–4.3 V under 1C.
LiNiO 2 (LNO) is one of the most promising cathode materials for lithium-ion batteries. Tungsten element in enhancing the stability of LNO has been researched extensively. However, the understanding of the specific doping process and existing form of W are still not perfect. This study proposes a lithium-induced grain boundary phase W doping mechanism. The results demonstrate that the introduced W atoms first react with the lithium source to generate a Li–W–O phase at the grain boundary of primary particles. With the increase of lithium ratio, W atoms gradually diffuse from the grain boundary phase to the interior layered structure to achieve W doping. The feasibility of grain boundary phase doping is verified by first principles calculation. Furthermore, it is found that the Li 2 WO 4 grain boundary phase is an excellent lithium ion conductor, which can protect the cathode surface and improve the rate performance. The doped W can alleviate the harmful H2↔H3 phase transition, thereby inhibiting the generation of microcracks, and improving the electrochemical performance. Consequently, the 0.3 wt% W-doped sample provides a significant improved capacity retention of 88.5 % compared with the pristine LNO (80.7 %) after 100 cycles at 2.8–4.3 V under 1C.
