Volume Expansion Research Articles

Biometabolically Derived Selenium Nanoparticles Armed with Protein Protective Suit toward High-Performance Li-Se Batteries.

Selenium (Se) serves as a burgeoning high-energy-density cathode material in lithium-ion batteries. However, the development of Se cathode is strictly limited by low Se utilization and inferior cycling stability arising from intrinsic volume expansion and notorious shuttle effect. Herein, a microbial metabolism strategy is developed to prepare "functional vesicle-like" Se globules via Bacillus subtilis subsp. from selenite in sewage, in which Se nanoparticles are armed with a natural biological protein membrane with rich nitrogen and phosphorus, achieving the eco-efficient conversion of trash into treasure (selenite, SeO3 2- → Selenium, Se). The appealing-design "functional vesicle-like" Se globules are beneficial to accommodate volume changes of Se in electrochemical reactions, confining polyselenides via chemisorption, and enhancing mechanical strength of electrode by associated bacteria debris, realizing comprehensive utilization of microorganism. By conceptualizing "functional vesicle-like" Se globules, rather than artificial Se-host composites, as cathode for lithium-selenium batteries, it exhibits outstanding cycling stability and improved rate performance. This strategy opens the door to design smart electrode materials with unattainable structure that cannot be achieved by traditional approaches, achieving eco-efficient conversion of pollutants into energy-storage nanomaterials, which will be a promising research field for interdisciplinary of energy, biology, and environment.

Impacts of CO2-CH4 Mixed Gas on Property of Formation Oil from the Bohai Oilfield

Mechanism analysis and technical scheme optimization on CO2 displacement and CO2 storage are based on the high-pressure physical properties of CO2-added formation oil. Oil and natural gas samples from the BZ25-1 block in the Bohai oilfield were used to conduct high-pressure physical property experiments to explore the impacts of CO2-CH4 mixed gas on the properties of formation oil. After injecting different amounts of mixed gas, the saturated pressure was measured by constant mass expansion test, the viscosity was measured by falling ball method, the expansion coefficient was measured by gas injection expansion test, and the gas–oil ratio and volume coefficient were obtained by single degassing test. The results show that with gas injection, the saturation pressure and dissolved gas–oil ratio of formation oil increase, the volume coefficient and expansion factor go up, while the oil viscosity reduces. With the increase in gas addition, the properties of formation oil continue to improve, but the increase in improvement becomes flat. With the increase in pressure, the amount of dissolved gas in the formation oil will also increase. High-purity CO2 is more helpful to change the properties of formation oil, while the gas mixed with CH4 is more beneficial to elevate the formation energy. For the BZ 25-1 block, the gas injection amount of about 80 mol% is appropriate and the CO2 purity of 60% can well balance the oil properties improvement and the formation pressure elevation.

Cross-Linkable Binders for Si Anodes in High-Energy-Density Lithium-Ion Batteries.

Although silicon (Si) has a high theoretical capacity, the large volume expansion during lithiation has greatly hindered its application in high-energy-density lithium-ion batteries (LIBs). Among the strategies for improving the performance of Si anode, the role of binders should not be underestimated. Here, a novel strategy for designing a cross-linkable binder for Si anode has been proposed. The binder with hydroxyl and nitrile groups can be in situ covalently cross-linked through the amide group in the batteries. The cross-linked binder (c-POAH) shows high elasticity and strong adhesion to Si particles and the current collector. Si||Li half coin cells using the c-POAH binder have excellent cycle performance and the capacity retention ratio is 67.1% after 100 cycles at 0.2 C. Scanning electronic microscopy images show that the c-POAH binder can contribute to suppressing the pulverization of the Si anode. Moreover, the investigation with X-ray photoelectronic spectrum demonstrates that the decomposition of the liquid electrolyte on Si anode has been mitigated and the c-POAH binder can promote the formation of a more stable SEI film. Our strategy of endowing the binder with good elasticity through in situ cross-linking has opened up a new route for developing binders, which will definitely promote the application of Si anodes in high-energy-density LIBs.

Underwater small target detection under YOLOv8-LA model

In the realm of marine environmental engineering, the swift and accurate detection of underwater targets is of considerable significance. Recently, methods based on Convolutional Neural Networks (CNN) have been applied to enhance the detection of such targets. However, deep neural networks usually require a large number of parameters, resulting in slow processing speed. Meanwhile, existing methods present challenges in accurate detection when facing small and densely arranged underwater targets. To address these issues, we propose a new neural network model, YOLOv8-LA, for improving the detection performance of underwater targets. First, we design a Lightweight Efficient Partial Convolution (LEPC) module to optimize spatial feature extraction by selectively processing input channels to improve efficiency and significantly reduce redundant computation and storage requirements. Second, we developed the AP-FasterNet architecture for small targets that are commonly found in underwater datasets. By integrating depth-separable convolutions with different expansion rates into FasterNet, AP-FasterNet enhances the model’s ability to capture detailed features of small targets. Finally, we integrate the lightweight and efficient content-aware reorganization (CARAFE) up-sampling operation into YOLOv8 to enhance the model performance by aggregating contextual information over a large perceptual field and mitigating information loss during up-sampling.Evaluation results on the URPC2021 dataset show that the YOLOv8-LA model achieves 84.7% mean accuracy (mAP) on a single Nvidia GeForce RTX 3090 and operates at 189.3 frames per second (FPS), demonstrating that it outperforms existing state-of-the-art methods in terms of performance. This result demonstrates the model’s ability to ensure high detection accuracy while maintaining real-time processing capabilities.

In Situ Construction of Specific SEI Layer Affords Effective Prelithiation.

Silicon-based anodes have been attracting attention due to their high theoretical specific capacity, but their low initial Coulombic efficiency (ICE) seriously hinders their commercial application. Direct contact prelithiation is considered to be one of the effective means of solving this problem. By means of prelithiation, a specific solid electrolyte interphase (SEI) was constructed, which inhibited the volume expansion of the SiO/C composite anode during prelithiation and reduced the local current generated when the lithium source was in contact with the anode. On the one hand, it can reduce the side reactions derived from the decomposition of electrolytes in the prelithiation process, and on the other hand, it can slow down the prelithiation process and inhibit the volume expansion of the SiO/C composite anode in the prelithiation process. The results of XPS, TOF-SIMS, and other tests show that the use of an electrolyte whose main component is LiTFSI can construct SEI film whose main component is LiF, which to a certain extent can slow down the rate of prelithiation, reduce the local current generated when the lithium source is in contact with the negative electrode, minimize the occurrence of side reactions, and inhibit the volume expansion of the negative electrode material. The full battery assembled with NCM111 positive electrode still exhibits 83.5% capacity retention after 500 cycles at 1 C current density. These studies provide some ideas to enhance the performance of silicon-based materials.

Fabrication of a Stable and Highly Effective Anode Material for Li-Ion/Na-Ion Batteries Utilizing ZIF-12.

Transition metal selenides (TMSs) are receiving considerable interest as improved anode materials for sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) due to their considerable theoretical capacity and excellent redox reversibility. Herein, ZIF-12 (zeolitic imidazolate framework) structure is used for the synthesis of Cu2Se/Co3Se4@NPC anode material by pyrolysis of ZIF-12/Se mixture. When Cu2Se/Co3Se4@NPC composite is utilized as an anode electrode material in LIB and SIB half cells, the material demonstrates excellent electrochemical performance and remarkable cycle stability with retaining high capacities. In LIB and SIB half cells, the Cu2Se/Co3Se4@NPC anode material shows the ultralong lifespan at 2000 mAg-1, retaining a capacity of 543 mAhg-1 after 750 cycles, and retaining a capacity of 251 mAhg-1 after 200 cycles at 100 mAg-1, respectively. The porous structure of the Cu2Se/Co3Se4@NPC anode material can not only effectively tolerate the volume expansion of the electrode during discharging and charging, but also facilitate the penetration of electrolyte and efficiently prevents the clustering of active particles. In situ X-ray difraction (XRD) analysis results reveal the high potential of Cu2Se/Co3Se4@NPC composite in building efficient LIBs and SIBs due to reversible conversion reactions of Cu2Se/Co3Se4@NPC for lithium-ion and sodium-ion storage.

A facile superlithiophilic 3D host with a transition metal oxide heterostructure for ultrastable zero-volume-expansion lithium metal anodes

Lithium metal batteries (LMBs) are widely recognized as the candidate for next-generation energy devices due to their unprecedented capacity and low electrochemical potential. Nonetheless, their practical implementation has been hindered by the dendrite formation and unstable solid electrolyte interface (SEI). In this study, we introduce a novel approach involving the in-situ growth of a ZnO–CuO heterostructure within a crack shield construction on a three-dimensional (3D) copper foam host. Computational COMSOL simulations reveal remarkable improvements in homogenizing lithium ion flux subsequent to decoration. Through galvanostatic measurements, the Li@ZnO-CuO-CF electrode exhibits an exceptionally low 0.2 V hysteresis, no volume expansion and uniform lithium deposition in symmetry cells under a 50 mA cm−2 current density. Furthermore, the electrode retains 95.4 % initial capacity after 600 cycles at 0.5C and 85.5 % initial capacity after 220 cycles at 1 C when coupled with a LiFePO₄ (LFP) cathode. This work sheds light on the facile fabrication of practical Li metal anodes for high-energy-density LMBs.

Lithiation Depth Regulation of Silicon Anodes toward Excellent Stability.

Silicon (Si) is an appealing choice of anode for next-generation lithium ion batteries with high energy density, but its dramatic volume expansion makes it a tremendous challenge to achieve acceptable stability. Herein, we demonstrate that no capacity decay is observed during the testing period when the lithiation depth of Si nanoparticles is regulated at 2000 mAh g-1 or below, the fracture of Si anode films is well mitigated under suitable regulation of lithiation depth, and the cycled Si remains particulate without turning flocculent as under full lithiation. In addition, the solid electrolyte interphase (SEI) with a LiF-dominated outer region produced under lithiation regulation could better passivate the Si anodes and prevent further electrolyte decomposition than the mosaic-type SEI formed under full lithiation. Regulating lithiation depth proved to be a feasible solution to the pressing volume issues, and optimization of capacity utilization should be considered as much as materials-level optimization.

Evaluating and classifying market alternatives using the CAPMA technique to assess potential export volume: an application for Turkey’s fig exports

PurposeAppropriate target market selection and classification are complex, time-consuming, and strategically important management decisions. The current study proposes and implements a new systematic approach that evaluates and ranks alternative markets’ potential to increase the export volume of Turkey’s fig exports.Design/methodology/approachThe classification approach of potential market alternatives (CAPMA) method, which was developed to evaluate, compare, and classify alternative markets according to their potential, was used in this study. CAPMA, an objective decision-making technique, is based on calculating the classification coefficient and classifying the alternatives into four dimensions, taking this coefficient into consideration. In the current study, 25 alternative markets were analysed on the basis of four evaluation criteria and classified into four dimensions according to their potential to increase export volume.FindingsAccording to the application results, alternative markets with the greatest potential to increase export volume were identified as the United States of America (USA), Netherlands, China, and Spain. The USA has the greatest potential for expansion of export volume. By implementing correct and effective marketing strategies, fig export volume has the potential to reach very high levels.Originality/valueThe study’s results on alternative markets for fig exports were categorized, countries with greater potential to increase export volume were identified, and findings that could contribute to the development of the sector were obtained. The approach proposed in the current research can be used to determine the target market of many other products, especially agricultural products, whose production is concentrated within a specific geography.

Change in Visual Acuity of Patients With Fuchs Endothelial Corneal Dystrophy Over 1 Year.

To determine whether the clinical and paraclinical course of Fuchs endothelial corneal dystrophy (FECD) over 1 year is related to the extent of triplet repetition in the transcription factor 4 (TCF4) gene. A prospective study with a 1-year follow-up was conducted. A total of 104 patients (160 eyes) with FECD and an equivalent number of age- and sex-matched control subjects without FECD were included. At inclusion, the corneas were graded using the modified Krachmer grade (KG) and patients were genotyped for the number of trinucleotide repeats (TNRs) in the TCF4 gene by the short tandem repeat assay. Visual acuity, Scheimpflug tomographic features, and the Visual Function and Corneal Health Status using a visual disability instrument were measured on 2 visits at 1-year intervals. KGs ranged from 1 to 6, and 46% of eyes had grades 1 to 4. 71% of the patients harbored TNR expansion (>40) versus 13% in control subjects (P < 0.001). Severity at inclusion was higher in the presence of TNR expansion when considering eyes independently (mean grade ±SD, 4.08 ± 1.42) without TNR expansion and 4.66 ± 1.27 with TNR expansion (P = 0.024). In 1 year, the ETDRS score significantly decreased by -2.97 (95% confidence interval -4.69 to -1.26, P = 0.001) and the ETDRS score with glare by -4.25 (95% confidence interval -6.22 to -2.27, P < 10-5). There was no relationship between the rate of decline and TNR expansion or KG. Central corneal thickness and Visual Function and Corneal Health Status scores did not significantly vary. It is possible to measure a subtle progression of FECD over a period as short as 1 year. We did not find a relationship between the presence of TNR expansion and the speed of deterioration over 1 year. This work should facilitate the design of future clinical trials on FECD.Trial Registration-URL: ClinicalTrials.gov. Identifier: French Fuchs Follow-up Study (F3S): NCT03974230.

Change in Visual Acuity of Patients With Fuchs Endothelial Corneal Dystrophy Over 1 Year.

To determine whether the clinical and paraclinical course of Fuchs endothelial corneal dystrophy (FECD) over 1 year is related to the extent of triplet repetition in the transcription factor 4 (TCF4) gene. A prospective study with a 1-year follow-up was conducted. A total of 104 patients (160 eyes) with FECD and an equivalent number of age- and sex-matched control subjects without FECD were included. At inclusion, the corneas were graded using the modified Krachmer grade (KG) and patients were genotyped for the number of trinucleotide repeats (TNRs) in the TCF4 gene by the short tandem repeat assay. Visual acuity, Scheimpflug tomographic features, and the Visual Function and Corneal Health Status using a visual disability instrument were measured on 2 visits at 1-year intervals. KGs ranged from 1 to 6, and 46% of eyes had grades 1 to 4. 71% of the patients harbored TNR expansion (>40) versus 13% in control subjects (P < 0.001). Severity at inclusion was higher in the presence of TNR expansion when considering eyes independently (mean grade ±SD, 4.08 ± 1.42) without TNR expansion and 4.66 ± 1.27 with TNR expansion (P = 0.024). In 1 year, the ETDRS score significantly decreased by -2.97 (95% confidence interval -4.69 to -1.26, P = 0.001) and the ETDRS score with glare by -4.25 (95% confidence interval -6.22 to -2.27, P < 10-5). There was no relationship between the rate of decline and TNR expansion or KG. Central corneal thickness and Visual Function and Corneal Health Status scores did not significantly vary. It is possible to measure a subtle progression of FECD over a period as short as 1 year. We did not find a relationship between the presence of TNR expansion and the speed of deterioration over 1 year. This work should facilitate the design of future clinical trials on FECD.Trial Registration-URL: ClinicalTrials.gov. Identifier: French Fuchs Follow-up Study (F3S): NCT03974230.

Nickel-doped CNTs composite as cathode by sulfur vapor deposition for high-performance all-solid-state lithium‑sulfur batteries

Shuttle effect of polysulfide in the cathode and the safety issues arising from dendrite formation at Li metal anode are the main challenges of traditional liquid lithium‑sulfur batteries. In order to solve the shuttle effect and prevent short circuit, the all-solid-state lithium‑sulfur battery (ASSLSB) is proposed. However, the huge volume expansion of sulfur and the improvement of sulfur conversion efficiency during charge and discharge, which could lead to the limitation of electrochemical performance. Herein, a homogeneous Ni-doped carbon-nanotubes (H-Ni-SVD@CNT) composite cathode of ASSLSB is prepared by sulfur vapor deposition to confine sulfur and promote the conversion of sulfur and Li2S. In this work, SVD-5-S@CNT composite cathode demonstrates high reversible discharge capacity of 1001.1 mAh g−1 after 127 cycles and capacity retention rate of 78.6 % at the rate of 0.1C and 60 °C. Moreover, H-Ni-SVD@CNT composite cathode exhibits superior electrochemical performance, displaying the discharge specific capacity of 1519.3 mAh g−1 at 0.1C and 60 °C. Meanwhile, the discharge specific capacity of H-Ni-SVD@CNT composite cathode is 1060.9 mAh g−1 at room temperature. The synergistic effect of physical confinement and chemical catalysis improves the electrochemical performance of the all-solid-state lithium‑sulfur battery. This work proposes a new strategy for the cathode structure design of the all-solid-state lithium‑sulfur battery.

Nickel-doped CNTs composite as cathode by sulfur vapor deposition for high-performance all-solid-state lithium‑sulfur batteries

Shuttle effect of polysulfide in the cathode and the safety issues arising from dendrite formation at Li metal anode are the main challenges of traditional liquid lithium‑sulfur batteries. In order to solve the shuttle effect and prevent short circuit, the all-solid-state lithium‑sulfur battery (ASSLSB) is proposed. However, the huge volume expansion of sulfur and the improvement of sulfur conversion efficiency during charge and discharge, which could lead to the limitation of electrochemical performance. Herein, a homogeneous Ni-doped carbon-nanotubes (H-Ni-SVD@CNT) composite cathode of ASSLSB is prepared by sulfur vapor deposition to confine sulfur and promote the conversion of sulfur and Li2S. In this work, SVD-5-S@CNT composite cathode demonstrates high reversible discharge capacity of 1001.1 mAh g−1 after 127 cycles and capacity retention rate of 78.6 % at the rate of 0.1C and 60 °C. Moreover, H-Ni-SVD@CNT composite cathode exhibits superior electrochemical performance, displaying the discharge specific capacity of 1519.3 mAh g−1 at 0.1C and 60 °C. Meanwhile, the discharge specific capacity of H-Ni-SVD@CNT composite cathode is 1060.9 mAh g−1 at room temperature. The synergistic effect of physical confinement and chemical catalysis improves the electrochemical performance of the all-solid-state lithium‑sulfur battery. This work proposes a new strategy for the cathode structure design of the all-solid-state lithium‑sulfur battery.

Mechanical Properties and Durability of Steel Slag-mineral Powder-coal Gangue Mixture by Uniform Design for Pavement Base

To realize the utilization of industrial solid waste resources and solve the shortage problem of pavement materials, this paper uses steel slag, mineral powder, and coal gangue to prepare a mixture. A uniform test with 2 factors and 6 levels was designed. Through regression analysis, response surfaces were established to study the mechanical properties of the coal gangue mixture. The hydrated products at different ages were microscopically analyzed by XRD and SEM. The durability including freeze-thaw cycles, dry and wet cycles, and immersion expansion rate were researched. The results show that the 7d unconfined compressive strength of the mixture reaches 2.14 – 6.46 MPa, with a 180d resilience modulus of 954 – 1098 MPa, and a 180d splitting tensile strength of 0.66 – 0.83 MPa. With the increase of steel slag content, the 7d unconfined compressive strength of the mixture first decreases and then increases. The content of mineral powder is positively correlated with the 7d unconfined compressive strength. The 180d compressive resilience modulus decreases first and then increases with the increase of steel slag and mineral powder content. The 180d splitting tensile strength is positively correlated with the content of steel slag and mineral powder. The mixture is less affected by freeze-thaw cycles, with mass loss rates of only 1.77 % – 2.13 %. The mass loss rate of the admixture is 0.87 % – 0.99 % after 10 dry and wet cycles, and the strength is slightly improved. The maximum expansion rate of the mixtures immersed in water for 10d is only 0.28 %. The hydrated reaction between steel slag, mineral powder and coal gangue promotes the formation of more hydration products such as AFt, C-S-H, CaAl2(SiO4), and Ca(OH)2. The C-S-H and CaAl2(SiO4) are intertwined into a dense network to wrap Ca(OH)2, which improves the compactness of the mixture and effectively resists the freeze-thaw expansion stress. The steel slag-mineral powder-coal gangue mixture meets the requirements of relevant norms and can be well used in pavement bases.

Integrated renal and sympathetic mechanisms underlying the development of sex- and age-dependent hypertension and the salt sensitivity of blood pressure.

Aging is a non-modifiable understudied risk factor for hypertension. We hypothesized that sympathetically mediated activation of renal sodium reabsorption drives age-dependent hypertension and the salt sensitivity of blood pressure (BP). Using 3-, 8-, and 16-month-old male and female Sprague-Dawley rats as a model of normal aging, we assessed BP, indices of sympathetic tone, and the physiological responses to acute and chronic sodium challenge including sodium chloride cotransporter (NCC) regulation. The effects of renal nerve ablation and NCC antagonism were assessed in hypertensive male rats. We observed sex-dependent impaired renal sodium handling (24h sodium balance (meq), male 3-month 0.36 ± 0.1 vs. 16-month 0.84 ± 0.2; sodium load excreted during 5% bodyweight isotonic saline volume expansion (%) male 3-month 77 ± 5 vs. 16-month 22 ± 8), hypertension (MAP (mmHg) male 3-month 123 ± 4 vs. 16-month 148 ± 6), and the salt sensitivity of BP in aged male, but not female, rats. Attenuated sympathoinhibitory afferent renal nerve (ARN) responses contributed to increased sympathetic tone and hypertension in male rats. Increased sympathetic tone contributes to renal sodium retention, in part through increased NCC activity via a dysfunctional with-no-lysine kinase-(WNK) STE20/SPS1-related proline/alanine-rich kinase signaling pathway, to drive hypertension and the salt sensitivity of BP in aged male rats. NCC antagonism and renal nerve ablation, which reduced WNK dysfunction and decreased NCC activity, attenuated age-dependent hypertension in male Sprague-Dawley rats. The contribution of an impaired sympathoinhibitory ARN reflex to sex- and age-dependent hypertension in an NCC-dependent manner, via an impaired WNK1/WNK4 dynamic, suggests this pathway as a mechanism-based target for the treatment of age-dependent hypertension.

Tightly confined tellurium nanocrystals in few-layer expanded graphite with Te–C bonds toward highly reversible zinc storage

Tellurium (Te) has great potential as high-performance cathode materials for aqueous zinc-ion batteries (AZIBs) owing to high electronic conductivity and volumetric capacity. Nevertheless, its poor utilization and large volume expansion result in insufficient rate and cycle performances, thereby, impeding practical application. Herein, a kind of Te/carbon composite was prepared via a ball-milling method, in which Te nanocrystals were tightly confined in few-layer expanded graphite (EG) with Te–C bonds (denoted as Te@EG). In addition to maintaining structural stability, such unique nanocomposite shows abundant electrochemically active sites and efficient charge transfer channels, which is beneficial to the utilization of Te. More importantly, the Te–C bonds between Te nanocrystals and EG can enhance the adsorption of Zn2+ and reduce the Zn2+ migration barrier, which contributes to promoting electrochemical kinetics. Consequently, the Te@EG cathode for the AZIBs exhibits sufficient specific capacity (412 mAh g–1 at 0.1 A g–1), high-rate performance (284 mAh g–1 at 3 A g–1), and reliable cycling stability (94% capacity retention at 1 A g–1 after 500 cycles). Furthermore, the soft-packaged Zn//Te@EG battery delivers excellent flexibility and cycling stability. This study offers a perspective on rational design of Te-based cathodes for practical AZIBs.

Densification of Alloying Anodes for High Energy Lithium-Ion Batteries: Critical Perspective on Inter- Versus Intra-Particle Porosity.

High Li-storage-capacity particles such as alloying-based anodes (Si, Sn, Ge, etc.) are core components for next-generation Li-ion batteries (LIBs) but are crippled by their intrinsic volume expansion issues. While pore pre-plantation represents a mainstream solution, seldom do this strategy fully satisfy the requirements in practical LIBs. One prominent issue is that porous particles reduce electrode density and negate volumetric performance (WhL-1) despite aggressive electrode densification strategies. Moreover, the additional liquid electrolyte dosage resulting from porosity increase is rarely noticed, which has a significant negative impact on cell gravimetric energy density (Whkg-1). Here, the concept of judicious porosity control is introduced to recalibrate existing particle design principles in order to concurrently boost gravimetric and volumetric performance, while also maintaining the battery's cycle life. The critical is emphasized but often neglected role that intraparticle pores play in dictating battery performance, and also highlight the superiority of closed pores over the open pores that are more commonly referred to in the literature. While the analysis and case studies focus on silicon-carbon composites, the overall conclusions apply to the broad class of alloying anode chemistries.

Vacancies-Induced Delocalized States Cobalt Phosphide for Binder-Free Anode Toward Stable and High-Rate Sodium-Ion Batteries.

Metal phosphides with easy synthesis, controllable morphology, and high capacity are considered as potential anodes for sodium-ion batteries (SIBs). However, the inherent shortcomings of metal phosphating materials, such as conductivity, kinetics, volume strain, etc are not satisfactory, which hinders their large-scale application. Here, a CoP@carbon nanofibers-composite containing rich Co─N─C heterointerface and phosphorus vacancies grown on carbon cloth (CoP1-x@MEC) is synthesized as SIB anode to accomplish extraordinary capacity and ultra-long cycle life. The hybrid composite nanoreactor effectively impregnates defective CoP as active reaction center while offering Co─N─C layer to buffer the volume expansion during charge-discharge process. These vast active interfaces, favored electrolyte infiltration, and a well-structured ion-electron transport network synergistically improve Na+ storage and electrode kinetics. By virtue of these superiorities, CoP1-x@MEC binder-free anode delivers superb SIBs performance including a high areal capacity (2.47 mAh cm-2@0.2mA cm-2), high rate capability (0.443 mAh cm-2@6mA cm-2), and long cycling stability (300 cycles without decay), thus holding great promise for inexpensive binder-free anode-based SIBs for practical applications.

Effect of Annealing Temperature on Microstructure and Properties of DH Steel and Optimization of Hole Expansion Property

In this article, DH steel containing Nb and Nb-Cu above 1000 MPa was designed, and its phase transformation law was analyzed through thermal expansion tests. The influence of annealing temperature on the microstructure and properties of DH steel was studied using a continuous annealing simulation testing machine, SEM, and tensile testing machine. The results showed that under a continuous annealing process, the test steel is composed of ferrite, martensite, a small amount of bainite, and residual austenite. The tensile strength decreases with the increase in annealing temperature, Cu element is dissolved in the matrix which produces solid solution strengthening and results in an increase in the strength of Cu-bearing test steel. Finally, 1180 MPa grade DH steel with excellent comprehensive properties was obtained at an annealing temperature of 840 °C and an overaging temperature of 340 °C. The expansion performance of the experimental steel was studied and optimized. Under the step heating annealing process, the experimental steel is composed of tempered martensite, ferrite, and residual austenite, with smaller differences in hardness between different phases, lower average dislocation density, and better expansion performance. Cu-bearing DH steel achieved an excellent match of strength and plasticity of 1289 MPa × 19.8%, with the hole expansion rate of 21.9% and the loss rate of hole expansion rate of 10%.

Effect of Annealing Temperature on Microstructure and Properties of DH Steel and Optimization of Hole Expansion Property

In this article, DH steel containing Nb and Nb-Cu above 1000 MPa was designed, and its phase transformation law was analyzed through thermal expansion tests. The influence of annealing temperature on the microstructure and properties of DH steel was studied using a continuous annealing simulation testing machine, SEM, and tensile testing machine. The results showed that under a continuous annealing process, the test steel is composed of ferrite, martensite, a small amount of bainite, and residual austenite. The tensile strength decreases with the increase in annealing temperature, Cu element is dissolved in the matrix which produces solid solution strengthening and results in an increase in the strength of Cu-bearing test steel. Finally, 1180 MPa grade DH steel with excellent comprehensive properties was obtained at an annealing temperature of 840 °C and an overaging temperature of 340 °C. The expansion performance of the experimental steel was studied and optimized. Under the step heating annealing process, the experimental steel is composed of tempered martensite, ferrite, and residual austenite, with smaller differences in hardness between different phases, lower average dislocation density, and better expansion performance. Cu-bearing DH steel achieved an excellent match of strength and plasticity of 1289 MPa × 19.8%, with the hole expansion rate of 21.9% and the loss rate of hole expansion rate of 10%.