Rapid development of portable or wearable devices, which is inspired by requirements of instant messaging, health monitoring and handling official business, urgently demands more tiny, flexible and light power sources. Fiber-shaped batteries explored in recent years become a prospective candidate to satisfy these demands. With 1D architecture, the fiber-shaped batteries could be adapted to various deformations and integrated into soft textile and other devices. Numerous researches have been reported and achieved huge promotion. To give an overview of fiber-shaped batteries, we summarized the development of fiber-shaped batteries in this review, and discussed the structure and materials in fiber-shaped batteries. The flexibility of batteries with the potential application of the batteries was also exhibited and showed the future perspective. Finally, challenges in this field were discussed, hoping to reveal research direction towards further development of fiber-shaped batteries.
Nanocomposite dielectrics show great promising application in developing next generation wearable all-solid-state cooling devices owing to the possessed advantages of high cooling efficiency, light-weight and small volume without the induced greenhouse effect or serious harm to ozone layer in the exploited refrigerants. However, low electrocaloric strength in nanocomposite dielectric is severely restricting its wide-spread application because of high applied operating voltage to improve electrocaloric effect. After addressing the chosen optimized ferroelectric ceramic and ferroelectric polymer matrix in conjunction with the analysis of crucial parameters, recent progress of electrocaloric effect (ECE) in polymer nanocomposites has been considerably reviewed. Subsequently, prior to proposing the conceptual design and devices/systems in electrocaloric nanocomposites, the existing developed devices/systems are reviewed. Finally, conclusions and prospects are conducted, including the aspects of materials chosen, structural design and key issues to be considered in improving electrocaloric effect of polymer nanocomposite dielectrics for flexible solidstate cooling devices.
In this study, a roasting enhanced flotation process was proposed to recover LiMn2O4 and grapite from waste lithium-ion batteries (LIBs). The effects of roasting temperature and time on the surface modification was investigated, and a series of analytical technologies were used to reveal process mechanism. The results indicate that LiMn2O4 can be effectively separated from graphite via flotation after the roasting. The flotation grade of LiMn2O4 was significantly increased from 63.10% to 91.36% after roasting at 550 °C for 2 h. The TG-DTG analysis demonstrates that the difficulty in flotation separation of LiMn2O4 from graphite is caused by the organic binder and electrolytes coating on their surfaces. The XRD, SEM, XPS, and contact angle analyses confirm that the organic films on the surfaces of those materials can be effectively removed by roasting, after which the wettability of LiMn2O4 is regained and thus the surface wettability difference between the cathode and anode materials is increased significantly. The closed-circuit flotation test indicates that a LiMn2O4 sample with high grade of 99.81% is obtained, while the recovery of LiMn2O4 is as high as 99.40%. This study provides an economical and eco-friendly way to recycling waste LIBs.
Recycling useful materials such as Ag, Al, Sn, Cu and Si from waste silicon solar cell chips is a sustainable project to slow down the ever-growing amount of waste crystalline-silicon photovoltaic panels. However, the recovery cost of the above-mentioned materials from silicon chips via acid-alkaline treatments outweights the gain economically. Herein, we propose a new proof-of-concept to fabricate Si-based anodes with waste silicon chips as raw materials. Nanoparticles from waste silicon chips were prepared with the high-energy ball milling followed by introducing carbon nanotubes and N-doped carbon into the nanoparticles, which amplifies the electrochemical properties. It is explored that Al and Ag elements influenced electrochemical performance respectively. The results showed that the Al metal in the composite possesses an adverse impact on the electrochemical performance. After removing Al, the composite was confirmed to possess a pronounced durable cycling property due to the presence of Ag, resulting in significantly more superior property than the composite having both Al and Ag removed.
With the continuous development of electronic industry, people’s demand for semiconductor materials is also increasing. How to prepare semiconductor materials with low cost, low energy consumption and high yield has become one of the hot spots of research. ZnTe is commonly used in the semiconductor industry due to its superior optoelectronic properties. Electrochemical deposition is one of the most frequently used methods to prepare ZnTe thin films. However, the traditional electrochemical deposition technology has many shortcomings, such as slow deposition rate and poor film quality. These hinder the large-scale promotion of zinc telluride electrochemical deposition technology. To solve the problems encountered in the preparation of semiconductor thin films by conventional electrochemical deposition, and based on the photoconductive properties of semiconductor materials themselves, the basic principles of photoelectrochemistry of semiconductor electrodes, and some characteristics of the electrochemical deposition process of semiconductor materials, the use of photoelectrochemical deposition method for the preparation of semiconductor materials was proposed. Firstly, the electrochemical behaviors (electrode reactions, nucleation growth and charge transport process) of the ZnTe electrodeposition under illumination and dark state conditions were studied. Then, the potentiostatic deposition of ZnTe was carried out under light and dark conditions. The phase structure, morphology and composition of the sediments were studied using X-ray diffractometer, scanning electron microscope and other testing methods. Finally, the photoelectrochemical deposition mechanisms were analyzed. Compared with conventional electrochemical deposition, photoelectrochemical deposition increases the current density during deposition and reduces the charge transfer impedance during ZnTe deposition process. In addition, since light illumination promotes the deposition of the difficult-to-deposit element Zn, the component ratio of ZnTe thin films prepared by photoelectrochemical deposition is closer to 1:1, making it a viable and reliable approach for ZnTe production.
It is the core to improve the electron/ion transfer features of Li4Ti5O12 for achieving high-rate anode in lithium ion batteries. By directly using graphite oxide powder, nano-Li4Ti5O12/reduced graphite oxide composite with mesopore-oriented porosity is prepared through one-pot facile ball-milling method in this work. Synthesis mechanism underlying the self-nucleophilic effect of oxygen-containing functional groups in graphite oxide is substantiated. Reactants can intercalate into graphite oxide bulk and in-situ generate nanoparticles. Subsequently, graphite oxide with nanoparticles generated inside can obtain a mesopore-oriented porous structure under ball-milling. Furthermore, the synergistic effects of Li4Ti5O12 nanoparticles and mesopore-oriented porosity strengthen composites with rapid Li+ diffusion and electron conductive frameworks. The obtained optimal LTO/GO-1.75 composite displays excellent high-rate capability (136 mA·h/g at 7000 mA/g) and good cycling stability (a capacity retention of 72% after 1000 cycles at 7000 mA/g). Additionally, the reactants concentration in this demonstrated strategy is as high as 30 wt%–40 wt%, which is over 6 times that of traditional methods with GO suspensions. It means that the strategy can significantly increase the yield, showing big potential for large-scale production.
Na-ion diffusion kinetics is a key factor that decided the charge/discharge rate of the electrode materials in Na-ion batteries. In this work, two extreme concentrations of NaMnO2 and Na2/3Li1/6Mn5/6O2 are considered, namely, the vacancy migration of Na ions in the fully intercalated and the migration of Na ions in the fully de-intercalated. The Na-vacancy and Na+ distribution in NaMnO2 migrated along oxygen dumbbell hop (ODH) and tetrahedral site hop (TSH), and the migration energy barriers were 0.374 and 0.296 eV, respectively. In NaLi1/6Mn5/6O2, the inhomogeneity of Li doping leads to the narrowing of the interlayer spacing by 0.9% and the increase of the energy barrier by 53.8%. On the other hand, due to the alleviation of Jahn-Teller effect of neighboring Mn, the bonding strength of Mn-O was enhanced, so that the energy barrier of path 2–3 in Mn-L1 and Mn-L2 was the lowest, which was 0.234 and 0.424 eV, respectively. In Na1/6Li1/6Mn5/6O2, the migration energy barriers of Na-L2 and Na-L3 are 1.233 and 0.779 eV, respectively, because Li+ migrates from the transition (TM) layer to the alkali metal (AM) layer with Na+ migration, which requires additional energy.
Lithium-sulfur (Li-S) batteries have been considered as the next generation high energy storage devices. However, its commercialization has been hindered by several issues, especially the dissolution and shuttle of the soluble lithium polysulfides (LiPSs) as well as the slow reaction kinetics of LiPSs which may make shuttling effect even worse. Herein, we report a strategy to address this issue by in-situ transformation of Co—Nx coordinations in cobalt polyphthalocyanine (CoPPc) into Co nanoparticles (Co NPs) embedded in carbon matrix and mono-dispersed on graphene flakes. The Co NPs can provide rich binding and catalytic sites, while graphene flakes act as ideally LiPSs transportation and electron conducting platform. With a remarkable enhanced reaction kinetics of LiPSs via these merits, the sulfur host with a sulfur content up to 70 wt% shows a high initial capacity of 1048 mA·h/g at 0.2C, good rate capability up to 399 mA·h/g at 2C.
Vanadium redox flow batteries (VRFBs) are one of the most promising energy storage systems owing to their safety, efficiency, flexibility and scalability. However, the commercial viability of VRFBs is still hindered by the low electrochemical performance of the available carbon-based electrodes. Defect engineering is a powerful strategy to enhance the redox catalytic activity of carbon-based electrodes for VRFBs. In this paper, uniform carbon defects are introduced on the surfaces of carbon felt (CF) electrode by Ar plasma etching. Together with a higher specific surface area, the Ar plasma treated CF offers additional catalytic sites, allowing faster and more reversible oxidation/reduction reactions of vanadium ions. As a result, the VRFB using plasma treated electrode shows a power density of 1018.3 mW/cm2, an energy efficiency (EE) of 84.5%, and the EE remains stable over 1000 cycles.
Despite being a promising photoanode material for water splitting, WO3 has low conductivity, high onset potential, and sluggish water oxidation kinetics. In this study, we designed Ti-doped WO3 nanoplate arrays on fluoride-doped tin oxide by a seed-free hydrothermal method, and the effects of doping on the photoelectrochemical performance were investigated. The optimal Ti-doped WO3 electrode achieved a photocurrent density of 0.53 mA/cm2 at 0.6 V (vs Ag/AgCl), 110% higher than that of pure WO3 nanoplate arrays. Moreover, a significant cathodic shift in the onset potential was observed after doping. X-ray photoelectron spectroscopy valence band and ultraviolet — visible spectra revealed that the band positions of Ti-doped WO3 photoanodes moved upward, yielding a lower onset potential. Furthermore, electrochemical impedance spectroscopy measurements revealed that the conductivities of the WO3 photoanodes improved after doping, because of the rapid separation of photo-generated charge carriers. Thus, we report a new design route toward efficient and low-cost photoanodes for photoelectrochemical applications.
With increasing demand on energy density of lithium-ion battery, wide electrochemical window and safety performance are the crucial request for next generation electrolyte. Gel-electrolyte as a pioneer for electrolyte solidization development aims to solve the safety and electrochemical window problems. However, low ionic conductivity and poor physical performance prohibit its further application. Herein, a fast-ionic conductor (Li2.64(Sc0.9Ti0.1)2(PO4)3) (LSTP) was added into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) base gel-electrolyte to enhance mechanical properties and ionic conductivity. Evidences reveal that LSTP was able to weaken interforce between polymer chains, which increased the ionic conductibility and decreased interface resistance during the cycling significantly. The obtained LiFePO4/hybrid gel-electrolyte/Li-metal coin cell exhibited excellent rate capacity (145 mA·h/g at 1C, 95 mA·h/g at 3C, 28 °C) which presented a potential that can be comparable with commercialized liquid electrolyte system.
The conversion reaction-based anode materials of sodium ion batteries have relatively high capacity; however, the application of these materials is limited by their structural collapse due to the poor structure stability. In this work, MoSe2 nanosheets were synthesized by a solvothermal method. An organic solvent was intercalated into the MoSe2 materials to enlarge the interlayer spacing and improve the conductivity of the material. The MoSe2 material was coated with an organic pyrolysis carbon and then a uniform carbon layer was formed. The surface carbon hybridization of the nanosheet materials was realized by the introduction of heteroatoms during the sintering process. The as-prepared MoSe2@N, P-C composites showed a superior rate performance as it could maintain the integrity of the morphology and structure under a high current density. The composites had a discharge specific capacity of 302.4 mA·h/g after 100 cycles at 0.5 A/g, and the capacity retention rate was 84.96%.
To recycle arsenic from an As-Sb fly ash, a newly continuous reductive method for obtaining elemental As with additive of PbO was proposed. In the first reduction stage, PbO promoted the As segregation from the As-Sb fly ash, due to which most As volatilized and Sb retained in roasted residues in phases of As-Sb-Pb-O and As-Sb-Pb alloy. With the increase of PbO and reductant amounts, the Sb fixation rate increased in the first reduction stage, and further the Sb content in the elemental As obtained from the second reduction stage decreased. After being roasted for 30 min at 550 °C with the addition of 20% activated carbon and 12% PbO in the first reduction stage, the As volatilization rate and Sb fixation rate from the As-Sb fly ash reached 92.86% and 79.38%, respectively. Then through the second reduction of the volatile matters at 650 ° C, the As and Sb contents in the obtained elemental As reached 99.07 wt% and 0.22 wt% respectively, indicating that the obtained As could be used to prepare high purity As, thereby rendering the As-Sb fly ash recycling.
Unveiling the active site of an electrocatalyst is fundamental for the development of efficient electrode material. For the two-electron water oxidation to produce H2O2, competitive reactions, including four- and one-electron water oxidation and surface reconstruction derived from the high-oxidative environment co-existed, leading to great challenges to identify the real active sites on the electrode. In this work, Ti/TiO2-based electrodes calcined under air, nitrogen, or urea atmospheres were selected as electrocatalysts for two-electron water oxidation. Electrochemical analyses were applied to evaluate the catalytic activity and selectivity. The morphological and current change on the electrode surface were determined by scanning electrochemical microscopy, while the chemical and valence evolutions with depth distributions were tested by XPS combined with cluster argon ion sputtering. The results demonstrated that Ti/TiO2 nanotube arrays served as the support, while the functional groups of carbonyl groups and pyrrolic nitrogen derived from the co-pyrolysis with urea were the active sites for the H2O2 production. This finding provided a new horizon to design efficient catalysts for H2O2 production.
Creep ageing forming (CAF) has been widely used in the aerospace engineering, but how to optimize the processing conditions, especially under complex stress state of the CAF process for large-size components produced by friction-stir welding is still a great challenge to now. In this work, the creep ageing behaviors and underlying microstructure evolution of a thick friction-stir welded Al-Cu alloy plate after CAF process under different stress levels are systematically investigated. The creep strain and the strength of the joint are both significantly increased when the stress is close to the average yield strength of the initial weld joint. The grain size reduces while the local strain and dislocation density increase from top to bottom of the NZ; hence, the bottom layer of the weld joint exhibits higher creep strain and steady-stage creep strain rate during the CAF process. The results reveal that the gradient microstructures sensitive to the stress level effectively govern the creep-ageing performance from the upper to the bottom layer in a thick friction stir welded Al-Cu alloy plate. Rationally increasing the initial dislocation density of the weld joint can both enhance the tensile properties and promote the creep deformation of the weld joint for CAF process.
The nonlinear vibration of graphene platelets reinforced composite corrugated (GPRCC) rectangular plates with shallow trapezoidal corrugations is investigated. Since graphene platelets are prone to agglomeration, a multi-layer distribution is adopted here to match the engineering requirements. Firstly, an equivalent composite plate model is obtained, and then nonlinear equations of motion are derived by the von Kármán nonlinear geometric relationship and Hamilton’s principle. Afterwards, the Galerkin method and harmonic balance method are used to obtain an approximate analytical solution. Results show that the unit cell half period, unit cell inclination angle, unit cell height, graphene platelet dispersion pattern and graphene platelet weight fraction and geometry play important roles in the nonlinear vibration of the GPRCC plates.
In this work, the chromium aluminum nitride (CrAlN) coatings were prepared on TC11 titanium alloy by composite magnetic field cathodic arc ion plating with controllable pulse electromagnetic combined with permanent magnet. The effects of electromagnetic frequency on the morphology, microstructure, nano-hardness and elastic modulus of the coatings were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and nano-indenter. This paper has mainly studied the influence of CrAlN coatings which are prepared at various electromagnetic frequencies on the wear and erosion resistance through a series of wear and solid particle erosion experiments. It was found that the deposition rate of CrAlN coatings increases with the increase of electromagnetic frequency. And CrAlN coatings all preferentially grew along the (111) crystal plane. At 16.7 Hz, with the increase of pulsed electromagnetic frequency, the hardness is the highest (23.6 GPa) and the adhesion is the highest (41.5 N). In addition, the coating deposition exhibited the best wear and solid erosion resistance at 16.7 Hz and 33.3 Hz, the friction coefficient is about 0.35, and the erosion rate is about 0.2 µm/g at 30° and less than 1 µm/g at 90°, respectively. These results indicate that the CrAlN coating formed at an appropriate pulsed electromagnetic frequency can achieve excellent mechanical properties, wear and solid erosion resistance.
As one of the advanced and efficient means of joining, the clinching process is capable of joining sheets with different materials or different sheet thicknesses. In this article, a novel modified clinching process, i. e., the dieless clinching process, was executed to join AA6061 aluminum alloy with sheet thicknesses of 1.5, 2.0, 2.5 and 3.0 mm according to different sheet stack-ups. The geometrical characteristics, microhardness distribution, failure behavior, static strength, absorbed energy and instantaneous stiffness of the novel dieless joint were gotten and investigated. The results indicated that the sheet thickness ratio has a notable effect on the failure behavior and mechanical properties of the novel dieless clinched joint, and a relatively large sheet thickness ratio can improve the joint performance when joining sheets with different sheet thicknesses.
As part of the mosaic of micro-continents within the Central Asian Orogenic Belt (CAOB), the Xing’an-Airgin Sum Block (XAB) features increasingly-recognized Meso-Neoproterozoic geological records. However, the origin, temporal-spatial distribution of ancient materials, and their roles in crust evolution remain to debate. This paper presents an integrated study of zircon U−Pb ages and Hf−O isotopes for Mesoproterozoic and Paleozoic granites from the Erenhot region of central Inner Mongolia, along eastern CAOB. The intrusion of 1450 Ma syenogranite denotes that the Precambrian basement of XAB extends from Sonid Zuoqi westward to Erenhot. The 384 and 281 Ma monzogranites containing Mesoproterozoic xenocrystic zircons possess Proterozoic-dominant two-stage Hf model ages, further suggesting the wide existence of Proterozoic crust beneath western XAB. Cyclic Proterozoic crustal growth and reworking seem to show close linkages with the orogenesis during relevant supercontinent cycles. 1450–1360 Ma juvenile crustal growth at Erenhot and synchronous ancient crust reworking at Sonid Zuoqi and Abagaqi were likely resulted from retreating subduction involved in Columbia breakup, while 1.2–1.0 Ga reworking and 0.9–0.7 Ga growth events within the Erenhot basement might respond to assembly and breakup of Rodinia, respectively. Besides, our work confirms that reworking of Neoproterozoic crust played important roles during Paleozoic multi-stage accretion of CAOB.
For the 110 mining method, it is challenging to accurately calculate the support resistance of the roadway due to the lack of understanding of the dynamic movement of the overlying strata in this method. The consequential excessive support results in a significant increase in the cost of roadway support. The authors explored the overlying strata movement and roadway deformation of the gob-entry retaining in the 110 mining method to solve this problem. First, the typical stages of the roof-cutting gob-side entry were defined. Second, the mechanical model and calculation formula of the support resistance on the roof were explored. Then, using numerical simulation software, the starting ranges of the specific supports at different stages were verified and the feasibility of the support scheme was examined. Finally, combined with the field measurement data, the stress and the deformation of the gob roadway at different stages under the influence of two mining processes in the 110 mining method were obtained. The numerical simulation results obtained are consistent with the field test results, providing a theoretical basis for precision support at different stages by the 110 mining method.
Rock pillar is the key supporting component in underground engineering. During an earthquake, the key rock pillar must bear both the seismic load and the load transferred from other damaged pillars. This paper attempts to reveal the influence of the mainshock on damage evolution and failure characteristic of the key rock pillar during aftershocks by cyclic loading test of marble. Four levels of pre-damage stress (i.e., 10, 30, 50 and 70 MPa) in the first cycle were used to simulate the mainshock damage, and then cyclic stress with the same amplitude (namely 10 MPa) was conducted in the subsequent cycles to simulate the aftershock until rock failure. The results indicate that the presence of pre-damage has an obvious weakening effect on the bearing capacity and deformation resistance of rock materials during the aftershock process. Besides, the increase of pre-damage significantly changes the final failure pattern of the key rock pillar, and leads to an increase in the proportion of small-scale rock fragments. This study may contribute to understanding the seismic capacity of the unreinforced rock pillar during mainshock-aftershock seismic sequences and to optimizing the design of the key rock pillar in underground engineering.
The expansive clays are extremely sensitive to the slight moisture alteration, exhibiting sequentially volume change. Uneven settlement of the buildings and infrastructures underlying expansive soil is a critical challenge that geotechnical engineers have to deal with. Therefore, the objective of this study is to assess the alteration in the compressibility behavior of expansive clay respecting partial replacement of cement by zeolite in cemented samples. For this purpose, 7 and 28 d cured samples treated with 6%, 8%, 10%, and 12% cement addition and 0, 10%, 30%, 50%, 70%, and 90% cement replacement by zeolite were investigated through Atterberg limit and a series of one-dimensional consolidation tests to evaluate the consistency limits and compressibility alteration. The liquid limits of the soil samples indicated a decremental trend as the cement content rose. Afterward, the increase of zeolite replacement up to 30% in each specific cement content diminished liquid limit to its lowest value. Further increment of zeolite replacement increased the liquid limit of the soil-binder mixtures. The lowest plasticity index was also achieved at the 30% zeolite replacement percentage; hence, the lowest swelling potential would be resulted, concerning an indirect classification. The results of the consolidation experimentations disclosed that zeolite replacement had adverse influence on consolidation parameters of cemented samples such as compression index, swell index, coefficient of compressibility, coefficient of volume compressibility, and coefficient of consolidation after 7 d of curing whereas after 28 d of curing, the 30% zeolite-replaced samples represented the best consolidation parameters. Eventually, it can be stated that the addition of cement alongside the partial substitution of cement by zeolite can be a beneficial strategy for the geo-environmental targets of this study.
Restrained distortional buckling is an important buckling mode of steel-concrete composite box beams (SCCBB) under the hogging moment. Rotational and lateral deformation restraints of the bottom plate by the webs are essential factors affecting SCCBB distortional buckling. Based on the stationary potential energy principle, the analytical expressions for the rotational restraint stiffness (RRS) of the web upper edge as well as the RRS and the lateral restraint stiffness (LRS) of the bottom plate were derived. Also, the SCCBB critical moment formula under the hogging moment was derived. Using twenty specimens, the theoretical calculation method is compared with the finite-element method. Results indicate that the theoretical calculation method can effectively and accurately reflect the restraint effect of the studs, top steel flange, and other factors on the bottom plate. Both the RRS and the LRS have a nonlinear coupling relationship with the external loads and the RRS of the web’s upper edge. Under the hogging moment, the RRS of the web upper edge has a certain influence on the SCCBB distortional buckling critical moment. With increasing RRS of the web upper edge, the SCCBB critical moment increases at first and then tends to be stable.
Microbiologically-induced concrete corrosion (MICC) refers to chemical reactions between biologically produced sulphuric acid and with hydration products in the hardened concrete paste, resulting in an early reduction of strength, deterioration, and very severe circumstances, structural failure. This paper explores the bactericidal characteristics of cementitious materials with surface coated with modified zeolite-polyurethane. The zeolite-polyurethane coating incorporated with silver was studied in environments inoculated with A. thiooxidans bacteria for 8 consecutive weeks. The antibacterial characteristics were evaluated in terms of pH, optical density (OD), sulphate production and bacteria count to determine the effectiveness of the zeolite-polyurethane coatings in environments inoculated with A. thiooxidans bacteria producing the sulphuric acid. The results revealed that the samples incorporated with silver modified zeolites generally showed antibacterial performance (regardless of the zeolite type) compared with unmodified polyurethane coating. This was evaluated by the lack of bacteria attachment and the deformed microcolonies on the sample surface, lag in pH reduction, increase in OD, and sulphate production. The silver zeolites gained their antibacterial performance from the release of silver ions (Ag+) when the sample comes into contact with aqueous solutions. This results in the inhibition of cell functions of the bacteria and subsequently causes cell damage.
MgO-series expansive agents can effectively compensate for the shrinkage and deformation of concrete structures. However, few experimental studies have been conducted on MgO expansive agents, particularly concerning the difference between and effects of submicron-MgO and nano-MgO in high-performance concrete (HPC) with a low water-cement ratio, thereby limiting their application in practical engineering. To clarify the expansion effect and expansion mechanism of MgO expansive agents in HPC, the effects of submicron-MgO and nano-MgO on the strength, toughness, and expansion characteristics of HPC were examined. The test results showed that submicron-MgO and nano-MgO continued to hydrate in the cement environment to produce Mg(OH)2, thus improving the structural compactness and structural strength of HPC. Nano-MgO concrete was found to have more stable mechanical properties and better structural deformability than submicron-MgO concrete. This study provides effective data support and theoretical reference concerning the hydration expansion mechanisms and engineering applications of nano-expanded materials.