Excellent Dynamic Stability Research Articles

Design of Simulink-based 3D Hexapod Robot Model and Implementation of Hexapod Robot Foothold Planning

In this world, there are many dangerous and complicated environments in which humans cannot work. Mobile robots are an important method that people use to solve these problems. Hexapod robots are known for their excellent static and dynamic stability, as well as strong environmental adaptability in mobile robots. Hexapod robots play a critical role in overcoming complex and challenging terrain. The paper attempts to finish two different parts of the work. The first part is to construct a Simulink-based CORIN robot model, and the second part is to develop a foothold planning algorithm for hexapod robots. The highly visual robot model can be used to display the results of related algorithms. It can also be applied in the Simulink physical environment to simulate robot overturning recovery, robot wall walking and other advanced robot motions through the use of the contact force blocks. Moreover, for the foothold planning algorithm, a collision detection algorithm based on the distance between the feature points and the obstacles is implemented. 18 feature points are set on the CORIN robot to ensure that the robot optional footholds are all collision-free points. Based on the path length, the distance from the target point and the collision state, a cost function is established, which is used in the CORIN robot foothold path planning algorithm. Results show that based on the kinematics of CORIN robot leg and modeling method in the Simulink, a complete CORIN hexapod robot model that can be controlled by specifying the position of the end effector or setting three different revolute joint angles has been designed. Furthermore, a radical foothold planning algorithm that can avoid collisions and focus on reaching the target point is implemented.

A two-dimensional metallic SnB monolayer as an anode material for non-lithium-ion batteries.

Na-, K- and Mg-ion batteries (NIBs, KIBs and MIBs) have drawn considerable interest due to their high abundance and excellent safety. However, the lack of high-performance anode materials is a major obstacle to its development. A metallic SnB planar monolayer is predicted by using the two-dimensional global minimum structure search method of swarm intelligence. Based on first-principles calculations, we proved that the metal SnB monolayer has high binding energy and excellent dynamical, thermal and mechanical stability. It is worth noting that the SnB monolayer has several stable adsorption sites for Na-, K- and Mg-ions, so it has a high theoretical capacity of 620.93, 517.44 and 620.93 mA h g-1, respectively. For Na-, K- and Mg-ion batteries, the low diffusion barriers of the SnB monolayer are 0.22, 0.07 and 0.68 eV, and the low average open circuit voltages are 0.42, 0.49 and 0.23 V, which ensure long service life and fast charging in practical applications. In addition, it is proved that the SnB monolayer maintains excellent conductivity and stability during the charge-discharge process. The results show that the SnB monolayer offers innovative advantages for the development of new two-dimensional planar structures that further advance the development of anode materials for metal ion batteries.

A g-SiC[formula omitted] monolayer and its analogs: A new class of tunable Dirac cone materials and novel quantum spin Hall insulators

Two-dimensional (2D) Dirac cone materials have received wide attention for their advanced properties, such as nearly-zero effective masses and ultrahigh carrier mobility. However, the robust zero bandgap limited their applications in high-performance electronic devices. In this work, we proposed a series of new 2D Dirac cone materials, termed as g-AB6 monolayers (A = C, Si, and Ge; B = C, Si, Ge, and Sn). We found that the coexistence of sp2 and sp3 hybridization would heavily decrease the structural stability, hence the stable g-AB6 monolayers were only composed of sp2 or sp3 hybridized atoms. The electronic calculations revealed that all g-AB6 monolayers considered are 2D Dirac materials with linear energy dispersions near Fermi level, and they possess high Fermi velocities. Among them, the Fermi velocity of the g-SiC6 monolayer is up to 7.11 × 105m/s, which is the highest value among the known group IVA binary Dirac materials. Additionally, the Dirac cone of g-SiC6 monolayer could be modulated by applying moderate in-plane uniaxial or shear strains (<5%), which are much easier than that of graphene and silicene. Moreover, the g-SiC6, g-GeSi6, g-SiGe6, and g-GeSn6 monolayer have been identified with nontrivial Z2 topological invariant (Z2 = 1), and the g-GeSn6 monolayer was demonstrated as a room temperature topological insulator due to that spin–orbit coupling opens a large bandgap of 319 meV. Considering that the g-AB6 monolayers possess excellent dynamical, thermal, and mechanical stability, the g-AB6 monolayers are a promising candidate for realizing high-speed tunable electronic devices.

Remarkable-cycle-performance β-bismuthene/graphene heterostructure anode for Li-ion battery

Remarkable Li-ion battery (LIB) anode materials need to have long cycle life and fast charge/discharge rate, however they are difficult to be realized in the monolayer anode materials. The monolayer β-Bi has the stiffness of only 33.0 N/m, thus the Bi/G heterostructure is proposed to improve the electronic and mechanical properties and to produce better LIB anode performance in this paper. The calculated results show that Bi/G heterostructure has excellent thermodynamic, dynamical and mechanical stability. The band gap is only 0.04 eV, which ensures remarkable electrical conductivity. In addition, the Bi/G heterostructure has higher stiffness (369.2 N/m) than that of monolayer β-Bi and graphene. The diffusion barrier (Ebarrier) of 0.32 eV and volume expansion ratio (VER) of only 4% can ensure the rapid transport of Li+ ions in the charge/discharge cycling process and long life of the LIB. These calculated theoretical results for describing the detail properties of Li storage and diffusion in the Bi/G heterostructure can supply adequate conclusive evidence for the prediction of remarkable properties of Bi/G heterostructure as an anode material for LIBs.

In Silico Triple Targeting of SARS-CoV-2 3CLᵖʳᵒ, PLᵖʳᵒ, and RdRp by Philippine Antitubercular Natural Products Libraries

The global pandemic disease COVID-19 commands a number of host immunological responses to deadly cytokine-storm manifestations. Mitigation of incoming infectious comorbidities ushered by immunosuppression such as tuberculosis (TB) is warranted including the requirement of new drugs. Employment of computational screening methods and intricate selection of putative viral protein targets allows identification of lead mitigating compounds against COVID-19. Antitubercular natural products may offer privileged starting points as potential antagonistic prospects for SARS-CoV-2 non-structural proteins implicated in viral replication and infection mechanisms. In this study, antitubercular natural products from Philippine medicinal plants are repurposed as inhibitors of vital SARS-CoV-2 nsps such as 3CLpro (3-chymotrypsin-like protease), PLpro (papain-like protease), and RdRp (RNA-dependent RNA polymerase) using in silico methods. A total of 67 antitubercular compounds were computationally screened using molecular docking in 3CLpro, PLpro, and RdRp followed by subsequent ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis of top-binding compounds to assess their drug-likeness and pharmacokinetic properties. Based on the results of our molecular docking analysis, 10 antitubercular natural product cocktails exhibited strong binding propensities against 3CLpro, PLpro, and RdRp. Several compounds demonstrated multi- targeting inhibition to at least two vital non-structural proteins (nsps). Vobtusine lactone (1), deoxyvobtusine lactone (6), and deoxyvobtusine (7) exhibited superior target-specific binding while globospiramine (3) was found to be a potential multi-targeting alkaloid with amenable drug-like properties. The study elaborated for the first time, the computational screeningof antitubercular compounds against three vital targets of SARS-CoV-2 yielding potentialdrug-like compounds against COVID-19 infection. A combination of excellent binding scores,dynamic stability, drug-likeness, and pharmacokinetic properties identified vobtusine lactone(1), deoxyvobtusine lactone (6), deoxyvobtusine (7), and the triple targeting globospiramine (3)as promising leads representing new anti-SARS-CoV-2 scaffolds.

A new speed adaptive estimation method based on an improved flux sliding-mode observer for the sensorless control of PMSM drives

In this paper, an improved speed adaptive flux sliding-mode observer (FSMO) is presented for the sensorless control of surface-mounted permanent magnet synchronous motor (PMSM) drives. First, to suppress the chattering of the traditional FSMO, an algorithm for online adjusting the observer gain is designed. In this algorithm, a transition mode is introduced between the existing reaching and sliding modes, and an error criterion function with speed and current is constructed for the three motion modes. Second, to reduce the rotor speed estimation error, a new speed adaptive estimation method is presented instead of the traditional phase-locked loop (PLL). In this method, the adaptive law for estimating the speed is derived using Lyapunov stability and model reference adaptive theories. Meanwhile, the physical meaning of the speed adaptive law is illustrated. Finally, the proposed FSMO scheme is implemented on a TMS320F28335 digital signal processing (DSP) microcontroller-based surface-mounted PMSM sensorless control experimental bench. Test results demonstrate the excellent dynamic performance, robustness and stability of the proposed FSMO under various operating conditions.

ABX6 Monolayers: A new Dirac material family containing high Fermi velocities and topological properties

Dirac materials have received attracting attentions due to their intriguing properties and potential applications in advanced electronics. In this work, we reported 44 new two-dimensional Dirac materials, named ABX6 monolayers, by constructing group IVA, VA, and VIA elements with the same structural prototype. Our first principle calculations revealed that they show excellent dynamical stability, mechanical stability, and thermodynamics stability. Those monolayers possess the elastic constant from 23.93 to 245.57 N/m, attributing to broadly used mechanical strength materials. The electronic calculations show that the Dirac cones in all ABX6 monolayers are both located at K points in Brillouin zone and mainly contributed from the pz orbital of group IVA atoms and group VIA atoms. Their Fermi velocities are from 3.44 × 105 to 6.83 × 105 m/s, which is benefiting for the potential applications in high-speed electric devices. Moreover, it is interesting to notice that the ABX6 monolayers with heavy atoms, such as the ISbSn6 monolayer, exhibit a large band gap of ∼ 0.106 eV, due to the spin-orbital coupling effect. The further calculations reveal their nontrivial topological nature with topological edge states, indicating they could be used as potential dissipationless transport devices at room temperature.

First-principles calculations to investigate electronic structure and transport properties of CrC monolayers: A new horizon for spintronic application

Using density functional theory we have predicted new chromium carbide (CrC) monolayers with unique intrinsic ferromagnetism, high Curie temperature and high spin polarization. The 2D h-CrC emerges as graphene like planer structure, while t-CrC comes out as a buckled structure. The ab-initio molecular dynamics simulation and phonon dispersion spectra show that 2D CrC monolayers possess excellent thermal and dynamical stabilities and thus have promise for experimental synthesis. The h-CrC monolayer exhibits half-metallicity with 100% spin polarization, whereas t-CrC monolayer is 57.4% spin polarized with metallic nature. Both the monolayers possess hard ferromagnetism along with high Curie temperature (730 K and 280 K for h-CrC and t-CrC, respectively) as calculated by Quantum Monte Carlo simulations. Bias dependent spin resolved electronic transport reveals 100% spin filtering efficiency (SFE) of 2D h-CrC, whereas the t-CrC sheet achieve SFE upto 98.5%. All these properties confirm the CrC monolayers as potential candidates for spintronic devices.

Wiggling Mesopores Kinetically Amplify the Adsorptive Separation of Propylene/Propane.

Adsorptive separation is an appealing technology for propylene and propane separation; however, the challenge lies in the design of efficient adsorbents which can distinguish the two molecules having very similar properties. Here we report a kinetically amplified separation by creating wiggling mesopores in structurally robust carbon monoliths. The wiggling mesopores with alternating wide and narrow segments afford a surface area of 413 m2 g-1 and a tri-modal pore size distribution centered at 1.5, 4.2 and 6.6 nm, respectively. The synergistically kinetic and equilibrium effects were observed and quantitatively assessed, which together ensured a remarkable propylene/propane selectivity up to 39. This selectivity outperformed not only the available carbon adsorbents but also highly competitive among the dominated crystalline porous adsorbents. In addition, the wiggling mesoporous carbon adsorbent showed excellent dynamical separation stability, which ensured its great potential in practical molecular separations.

Wiggling Mesopores Kinetically Amplify the Adsorptive Separation of Propylene/Propane

AbstractAdsorptive separation is an appealing technology for propylene and propane separation; however, the challenge lies in the design of efficient adsorbents which can distinguish the two molecules having very similar properties. Here we report a kinetically amplified separation by creating wiggling mesopores in structurally robust carbon monoliths. The wiggling mesopores with alternating wide and narrow segments afford a surface area of 413 m2 g−1 and a tri‐modal pore size distribution centered at 1.5, 4.2 and 6.6 nm, respectively. The synergistically kinetic and equilibrium effects were observed and quantitatively assessed, which together ensured a remarkable propylene/propane selectivity up to 39. This selectivity outperformed not only the available carbon adsorbents but also highly competitive among the dominated crystalline porous adsorbents. In addition, the wiggling mesoporous carbon adsorbent showed excellent dynamical separation stability, which ensured its great potential in practical molecular separations.

Pickering emulsion stabilized by cellulosic fibers: Morphological properties-interfacial stabilization-rheological behavior relationships

This work aimed to study the stabilization mechanism induced by different morphologies of cellulosic fiber in O/W emulsion. Three types of cellulosic fibers were named squashed cellulose, incompletely nanofibrillated cellulose, and completely nanofibrillated cellulose, respectively. Squashed cellulose acted as barriers between the droplets to stabilize emulsion via depletion flocculation, whereas incompletely nanofibrillated and completely nanofibrillated cellulose formed covering layer via interfacial adsorption and connected adjacent droplets to create the droplet-fiber network structure via bridging flocculation. Differently, completely nanofibrillated cellulose formed the denser covering layer leading to a more stability of droplet. Importantly, it had the higher capacity of bridging flocculation, which can tightly connect the adjacent droplets to form a stronger droplet-fiber 3D network structure. Consequently, in rheological analysis including creep compliance, and dynamic modulus, the corresponding emulsions showed excellent anti-deformation ability and dynamic stability. This study provides practical guidance on the productions of foodstuff and cosmetic.

Germanether: a two-dimensional auxetic semiconductor with tunable direct-band-gap and high electron mobility

Pristine germanene is a zero-gap semi-metal, which may hinder its practical application in semiconducting devices. Here, on the basis of the structural characteristics of digermyl ether, we theoretically design a two-dimensional crystal, namely germanether. Germanether exhibits excellent dynamical and thermal stability. It possesses an indirect band gap of 1.37 eV and a high electron mobility of 2.32 × 103 cm2 V−1 s−1. The uniaxial strain and layer stacking order can trigger an indirect-to-direct band gap transition. More interestingly, germanether has remarkable in-plane negative Poisson’s ratios with the largest one (∼−0.2) five times of borophenes and three times of penta-graphene. The negative Poisson’s ratio arises from the interplay of Ge–O tetrahedron symmetry and Ge-4d orbitals involvement, which is different from previously reported auxetic materials. All these findings render germanether is a competitive material for the future application in nanomechanics and nanoelectronics.

Penta carbides: Two-dimensional group-IV semiconductors containing C2 dimers for nanoelectronics and photocatalytic water splitting

The discovery of novel materials with superior tailored properties is highly attractive for nano- and optoelectronics. Inspired by penta graphene, we introduce a novel family of two-dimensional group-IV materials with ${\mathrm{C}}_{2}$ dimers, namely penta carbides. The first-principles calculations reveal that the unitary, binary, and ternary penta carbides have excellent energetic, dynamical, thermal, and mechanical stability with remarkable properties. The unitary penta carbide displays auxetic behavior whereas the binary and ternary penta carbides posses near zero and positive Poisson's ratio. The phonon dispersion curves of penta carbides indicate a remarkable phononic gap, which can be tuned by alloy engineering and hydrogenation. They are semiconductor in nature with band-gap energy ranging from 1.35 and 2.39 eV. Alloying and strain engineering enable the direct modification of atomic bonding and thereby tuning of electronic band gap of penta carbides. Such novel tunable electronic and phononic properties of penta carbides can find applications in the field of nanoelectronics, sensors, and frequency filter applications. The band edge positions of penta carbides (except for Sn-based ones) straddle the redox potentials of water. Remarkably, penta carbides exhibit very high optical absorption in the visible and ultraviolet regions (up to ${10}^{\ensuremath{-}6} {\mathrm{cm}}^{\ensuremath{-}1}$). They have small and anisotropic carrier effective masses, indicating fast carrier transport characteristics and promoting the photo-generated electron-hole separation efficiency. The high specific surface areas, suitable and sizable band gaps, appropriate band edges, small effective carrier masses, and excellent optical absorption capability, all these exotic properties taken together, make penta carbides promising candidates for photocatalytic water splitting.

B5N3 and B7N5 Monolayers with High Carrier Mobility and Excellent Optical Performance.

An ab initio evolutionary search algorithm was combined with density functional theory (DFT) calculations to predict a series of 2-D BxNy (1 < x/y ≤ 2). Particularly, B5N3 and B7N5 monolayers have sufficiently low formation enthalpy and excellent dynamic stability that make them promising for synthesis in experiments. Electronic structure calculations reveal that B5N3 and B7N5 monolayers possess an indirect band gap of 1.99 eV and a direct band gap of 2.40 eV, respectively. The calculated absorption coefficients for B5N3 and B7N5 monolayers are significantly improved in the low end of the visible region compared with that of 2-D h-BN. Moreover, our calculations reveal that both B5N3 and B7N5 monolayers have high electron carrier mobilities. The narrow band gaps, high carrier mobilities, strong near-ultraviolet absorption, and high synthesis possibility of B5N3 and B7N5 monolayers render them promising new materials for application in novel electronics and environmentally benign solar energy conversion.

Two-dimensional IrN2 monolayer: An efficient bifunctional electrocatalyst for oxygen reduction and oxygen evolution reactions

The development of bifunctional electrocatalysts with good stability and high efficiency for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for renewable energy conversion and storage. Herein, by means of swarm-intelligence structure search and density functional theory (DFT) computations, we proposed a novel kind of two-dimensional (2D) monolayer with hypercoordinate structure as electrocatalysts for ORR/OER, namely, transition dinitride (TMN2, TM = V, Co, Rh, Pd, W, Re, and Ir) monolayer. Our result revealed that these TMN2 monolayers have excellent thermal, dynamic and chemical stability, as well as inherent metallic nature for their practical applications in electrocatalysis. More interestingly, among all 2D TMN2 materials, the IrN2 monolayer was suggested to perform as an ideal bifunctional electrocatalyst for ORR/OER with a low overpotential of 0.47 and 0.27 V, respectively, which is comparable to Pt and Ir- or Ru-based oxides. Furthermore, by examining the d-band centers of the active sites in different TMN2 monolayers, we well rationalized the superior catalytic activity of IrN2 monolayer for ORR/OER. Our findings not only further enrich 2D nanomaterials with hypercoordinate structure, but also open a new door to develop bifunctional oxygen electrocatalysts with high efficiency.

Two-dimensional intrinsic ferromagnetic monolayer transition metal oxyhydroxide

Using density functional theory within the generalized gradient approximation, we predict that monolayer vanadium oxyhydroxide (VOOH) and chromium oxyhydroxide (CrOOH) are two-dimensional (2D) ferromagnetic semiconductors. These two kinds of oxyhydroxides possess excellent thermal and dynamical stability as the free-standing 2D monolayer films. Our results show that the monolayer VOOH and CrOOH remain ferromagnetic ordering with the critical temperature up to $\ensuremath{\sim}100\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, and the ferromagnetic ordering is due to a superexchange interaction in the near-${90}^{\ensuremath{\circ}}$ V(Cr)-O-V(Cr) bonds in monolayer VOOH(CrOOH). However, the different occupancy of $d$ electrons between the ${\mathrm{V}}^{3+}$ and ${\mathrm{Cr}}^{3+}$ ions gives rise to the different axes or planes of easy magnetization and the different magnetic anisotropy energies between the monolayer VOOH and CrOOH. Our study demonstrates that monolayer transition metal oxyhydroxides could be one category of testing ground for the investigation of 2D ferromagnets.

Kirigami-Inspired Highly Stretchable, Conductive, and Hierarchical Ti3C2Tx MXene Films for Efficient Electromagnetic Interference Shielding and Pressure Sensing.

Although Ti3C2Tx MXene sheets are highly conductive, it is still a challenge to design highly stretchable MXene electrodes for flexible electronic devices. Inspired by the high stretchability of kirigami patterns, we demonstrate a bottom-up methodology to design highly stretchable and conductive polydimethylsiloxane (PDMS)/Ti3C2Tx MXene films for electromagnetic interference (EMI) shielding and pressure sensing applications by constructing wrinkled MXene patterns on a flexible PDMS substrate to create a hierarchical surface with primary and secondary surface wrinkles. The self-controlled microcracks created in the valley domains of the hierarchical film via a nonuniform deformation during prestretching/releasing cycles endow the hierarchical PDMS/MXene film with a high stretchability (100%), strain-invariant conductivity in a strain range of 0%-100%, and stable conductivities over an 1000-cycle fatigue measurement. The stretchable film exhibits a highly stable EMI shielding performance of ≈30 dB at a tensile strain of 50%, and its EMI shielding efficiency increases further to 103 dB by constructing a two-film structure. Furthermore, a highly stretchable and sensitive iontronic sensor array with integrated MXene-based electrodes and circuits is fabricated by a stencil printing process, exhibiting high sensitivity (66.3 nF kPa-1), excellent dynamic cycle stability over 1000 cycles under different frequencies, and sensitive pressure monitoring capability under a tensile strain of 50%.

Electronic, thermoelectric, transport and optical properties of MoSe2/BAs van der Waals heterostructures

The density functional theory (DFT) calculations were performed to systematically study the geometrical, electronic, thermoelectric, transport and optical properties of MoSe2/BAs van der Waals heterostructures (vdWHs). The different MoSe2 and BAs stacking configurations effect hardly on the band structure. The MoSe2/BAs vdWHs possesses excellent dynamical, thermal and mechanical stability, with a direct bandgap of 1.04 eV and type-I band alignment. The Seebeck coefficient and ZT suggest the possibility of MoSe2/BAs vdWHs for thermoelectric applications. The in-plane strains and external electric field can modulate the band structure to achieve the transition from type-I to type-II band alignment, and the direct band gap feature remains preserved. Under the in-plane strains and external electric field, one can find a remarkably high optical absorption coefficient (~105 cm−1) in the visible-ultraviolet region and the red shift in the optical absorption spectrum. Its high energy conversion efficiency of 20.08% making the heterostructure extremely potential in solar energy harvesting of low-dimensional excitonic solar cells. These properties of MoSe2/BAs vdWHs show their promising applications in optoelectronic, nanoelectronic and thermoelectronic fields.

Structure, phase stability, half-metallicity, and fully spin-polarized Weyl states in compound NaV2O4 : An example for topological spintronic material

Here we systematically investigate the structure, phase stability, half-metallicity, and topological electronic structure for a topological spintronic material $\mathrm{Na}{\mathrm{V}}_{2}{\mathrm{O}}_{4}$. The material has a tetragonal structure with excellent dynamical and thermal stabilities. It shows a half-metallic ground state, where only the spin-up bands are present near the Fermi level. These bands are demonstrated to form a nodal line with the double degeneracy on the ${k}_{z}=0$ plane. The nodal line is robust against spin-orbit coupling, under the protection of the mirror symmetry. The nodal line band structure is very clean, thus the drumhead surface states can be clearly identified. Remarkably, the nodal line and drumhead surface states have the $100%$ spin polarization, which are highly desirable for spintronics applications. In addition, by shifting the magnetic field in-plane, we find that the nodal line can transform into a single pair of Weyl nodes. The nodal-line and Weyl-node fermions in the bulk, as well as the drumhead fermions on the surface are all fully spin-polarized, which may generate interesting physical properties and promising applications.

High storage capacity and small volume change of potassium-intercalation into novel vanadium oxychalcogenide monolayers V2S2O, V2Se2O and V2Te2O: An ab initio DFT investigation

A new category of two-dimensional electrode materials, i.e., V2Ch2O (Ch = S, Se and Te) monolayers was explored for K-ion batteries (PIBs) based on principle of chemical exfoliation, density functional theory and ab initio molecular dynamics simulations. The V2Ch2O monolayers show low cleavage energies and excellent thermal, dynamical and mechanical stabilities. Adsorption energies of a potassium atom on the V2Ch2O monolayers are exothermic, which are of benefit to prevent forming dendrites. The existence of electrode potentials substantially decreases the diffusion barriers of potassium atoms on the three V2Ch2O monolayers. The V2Ch2O monolayers are able to maintain their metallic characteristics and single surface phase during the whole K-intercalation process, avoiding the decrease in electronic conductivity and the appearance of potential hysteresis. The theoretical specific capacities of the V2S2O, V2Se2O and V2Te2O monolayers are predicted to be 883.6, 583.1 and 431.0 mAh g−1, respectively, and the corresponding average open-circuit voltages are 0.449, 0.390 and 0.293 V, respectively. The maximum percentage changes in lattice parameters are 4.21%, 6.07% and 7.26% for the V2S2O, V2Se2O and V2Te2O monolayers, respectively. All the calculated properties indicate that the V2Ch2O monolayers are promising electrode materials for PIBs with high capacities and long cycle lives.