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1.
Proc Natl Acad Sci U S A ; 119(41): e2211059119, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36191201

RESUMO

All-solid-state Li-metal batteries (ASSLBs) are highly desirable, due to their inherent safety and high energy density; however, the irregular and uncontrolled growth of Li filaments is detrimental to interfacial stability and safety. Herein, we report on the incorporation of piezo-/ferroelectric BaTiO3 (BTO) nanofibers into solid electrolytes and determination of electric-field distribution due to BTO inclusion that effectively regulates the nucleation and growth of Li dendrites. Theoretical simulations predict that the piezoelectric effect of BTO embedded in solid electrolyte reduces the driving force of dendrite growth at high curvatures, while its ferroelectricity reduces the overpotential, which helps to regularize Li deposition and Li+ flux. Polarization reversal of soft solid electrolytes was identified, confirming a regular deposition and morphology alteration of Li. As expected, the ASSLBs operating with LiFePO4/Li and poly(ethylene oxide) (PEO)/garnet solid electrolyte containing 10% BTO additive showed a steady and long cycle life with a reversible capacity of 103.2 mAh g-1 over 500 cycles at 1 C. Furthermore, the comparable cyclability and flexibility of the scalable pouch cells prepared and the successful validation in the sulfide electrolytes, demonstrating its universal and promising application for the integration of Li metal anodes in solid-state batteries.

2.
Small ; : e2404135, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39087389

RESUMO

To effectively solve the challenges of rapid capacity decay and electrode crushing of silicon-carbon (Si-C) anodes, it is crucial to carefully optimize the structure of Si-C active materials and enhance their electron/ion transport dynamic in the electrode. Herein, a unique hybrid structure microsphere of Si/C/CNTs/Cu with surface wrinkles is prepared through a simple ultrasonic atomization pyrolysis and calcination method. Low-cost nanoscale Si waste is embedded into the pyrolysis carbon matrix, cleverly combined with the flexible electrical conductivity carbon nanotubes (CNTs) and copper (Cu) particles, enhancing both the crack resistance and transport kinetics of the entire electrode material. Remarkably, as a lithium-ion battery anode, the fabricated Si/C/CNTs/Cu electrode exhibits stable cycling for up to 2300 cycles even at a current of 2.0 A g-1, retaining a capacity of ≈700 mAh g-1, with a retention rate of 100% compared to the cycling started at a current of 2.0 A g-1. Additionally, when paired with an NCM523 cathode, the full cell exhibits a capacity of 135 mAh g-1 after 100 cycles at 1.0 C. Therefore, this synthesis strategy provides insights into the design of long-life, practical anode electrode materials with micro/nano-spherical hybrid structures.

3.
Phys Chem Chem Phys ; 26(24): 17075-17082, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38842020

RESUMO

The topological and magnetic properties induced by topological defects in graphene have attracted attention. Here, we study a novel topological defect structure for graphene nanoribbons interspersed with C558-line defects along the armchair boundary, which possesses topological properties and is tritopic. Using strain engineering to regulate the magnitude of hopping at defects, the position of the energy level can be easily changed to achieve a topological phase transition. We also discuss the local magnetic moment and the ferromagnetic ground state in the context of line defects. This leads to spin polarization of the whole system. Finally, when C558 graphene nanoribbons are controlled by a nonlocal exchange magnetic field, spin-polarized quantum conductivity occurs near the Fermi level. Consequently, spin filtering can be achieved by varying the incident energy of the electrons. Our results provide new insights into realizing topological and spin electronics in low-dimensional quantum devices.

4.
Phys Chem Chem Phys ; 26(19): 14244-14255, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38690716

RESUMO

In this work, PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 thin films with (002) preferred orientation were prepared using a pulsed laser deposition technique. The temperature dependence of resistivities ρI(T) was investigated under various applied DC currents. Colossal electroresistance (CER) effects were found in PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2. It was found that the positive CER values of PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 reach 3816% and 154% for I = 1.00 µA at 10 K, respectively. In addition, the ρI(T) cycle curves of PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 thin films showed a critical temperature similar to that of PbPdO2 (Tc = 260 K). Particularly, charge transfer between O1- and O2- was confirmed by in situ XPS. Additionally, based on first-principles calculations and internal electric field models, the CER and magnetic sources in PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 can be well explained. Finally, it was found that thin film samples doped with V and G ions exhibit weak localization (WL) and weak anti-localization (WAL) quantum transport properties. Ion doping leads to a transition from WAL to WL. The study results indicate that PbPdO2, one of the few oxide topological insulators, can exhibit novel quantum transport behavior after ion doping.

5.
Phys Chem Chem Phys ; 26(5): 4174-4183, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38230505

RESUMO

The utilization of high-voltage LiCoO2 is an effective approach to break through the bottleneck of practical energy density in lithium ion batteries. However, the structural and interfacial degradations at the deeply delithiated state as well as the associated safety concerns impede the application of high-voltage LiCoO2. Herein, we present a synergetic strategy for promoting the surface stability of LiCoO2 at high voltage by Ti-Mg-Al co-doping and systematically study the effects of the dopants on the surface stability, electronic structure and Li+ diffusion properties of the LiCoO2 (104) surface using first-principles calculations. It is found that Ti, Mg and Al dopants can be facilely introduced into the Co sites of the LiCoO2 (104) surface. Furthermore, the co-doping could significantly stabilize the surface oxygen of LiCoO2 at a high delithiation state. Particularly, by aggregating Ti-Mg-Al co-dopant distribution in the surface layer, surface oxygen loss is dramatically suppressed. In addition, analysis of the electronic structure indicates that Ti-Mg-Al co-doping can enhance the electronic conductivity of the LiCoO2 (104) surface and greatly inhibit the charge deficiency of the superficial lattice O atoms at a highly delithiated state. In spite of a negligible improvement in the surface Li+ diffusion kinetics, the Ti-Mg-Al surface-modified LiCoO2 is expected to exhibit improved electrochemical performance at high voltage due to its superior surface stability. Our results suggest that aggregating Ti, Mg and Al co-dopant distribution in the surface layer is a promising modulation strategy to synergistically promote the surface oxygen stability of LiCoO2 at high voltages.

6.
Nano Lett ; 23(9): 4032-4038, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37125767

RESUMO

Optical gain in solution-processable quantum dots (QDs) has attracted intense interest toward next-generation optoelectronics; however, the development of optical gain in heavy-metal-free QDs remains challenging. Herein, we reveal that the ZnSe1-xTex-based QDs show excellent optical gain covering the violet to near-red regime. A new gain mechanism is established in the alloy QDs, which promotes a theoretically threshold-less optical gain thanks to the ultrafast carrier localization and suppression of ground-state absorption by the Te-derived isoelectronic state. Further, we disclose that the hot-carrier trapping represents the main culprit to exacerbate the gain performance. With the increase of Te-to-Se ratio, a sub-band-gap photoinduced absorption (PA) appears and extinguishes the optical gain. To overcome this issue, we modulate the inner ZnSe shell thickness, and the gain is recovered by reducing the overlap between the gain and PA regions in the Te-rich QDs. Our finding represents a significant step toward sustainable QD-based optoelectronics.

7.
Beijing Da Xue Xue Bao Yi Xue Ban ; 56(4): 741-744, 2024 Aug 18.
Artigo em Zh | MEDLINE | ID: mdl-39041574

RESUMO

The mesothelium, which consists of a monolayer of mesothelial cells, extends over the surface of the serosal cavities (pleura, pericardium, peritoneum and tunica vaginalis). Mesothelial tumours of the tunica vaginalis is rare compared with those arise from pleura or peritoneum. According to World Health Organization 2022 Classification of Urinary and Male Genital Tumours (5th edition), mesothelial tumours of the tunica vaginalis were categorized into adenomatoid tumour, well-differentiated papillary mesothelial tumour (WDPMT) and mesothelioma. Since WDPMT of tunica vaginalis was rare, there was no consensus concerning the treatment of it. In this case report, a 29-year-old man who had endured intermittent right scrotal pain for 8 months, aggravating scrotal pain for 2 weeks was admitted. No symptoms, such as frequent, urgent, or painful urination were shown. Physical examination revealed the enlargement and tenderness of right scrotum, with no signs of lifting pain. The most recent scrotal ultrasonography before surgery revealed right hydrocele with maximum depth of 4 centimeters and poor blood flow of right testis. Under the circumstance of patient' s chronic history of testicular hydrocele, he underwent an emergency operation of right scrotal exploration and hydrocelectomy under epidural anesthesia. After opening the vagina tunic cavity, spot-like bleeding was observed on the right testicle, epididymis and vaginalis surface. The vaginalis was obviously thickened and the inner and outer walls were smooth. The post-operative histopathology revealed a grayish-brown tissue with a thickness of 0.3-0.5 cm, smooth inner and outer walls, and a suspected WDPMT with a diameter of 1. 5 cm. Immunohistochemical staining showed positive for Calretinin, BAP1, WT-1, CK5/6, D2-40 and P16,which confirmed the diagnosis of WDPMT. To sum up, the purpose of this case report was to raise awareness of a rare disease WDPMT, which was usually asymptomatic and could be diagnosed by pathology and immunohistochemistry. The disease should be differentiated from testicular torsion, epididymitis, orchitis and oblique inguinal hernia in symptoms, and from malignant mesothelioma and adenomatoid tumour in pathology. Because of the rarity of the cases, there was no unified standard for the treatment of WDPMT at present. The common treatment methods reported in literature included orchidectomy and vaginectomy. Due to the lack of understanding of this disease, postoperative follow-up was still recommended for at least 5 years.


Assuntos
Neoplasias Testiculares , Humanos , Masculino , Adulto , Neoplasias Testiculares/patologia , Neoplasias Testiculares/cirurgia , Neoplasias Testiculares/diagnóstico , Neoplasias Mesoteliais/patologia , Neoplasias Mesoteliais/diagnóstico , Escroto/patologia , Escroto/cirurgia , Hidrocele Testicular/cirurgia , Hidrocele Testicular/diagnóstico , Tumor Adenomatoide/patologia , Tumor Adenomatoide/cirurgia , Tumor Adenomatoide/diagnóstico
8.
Phys Chem Chem Phys ; 25(17): 12013-12024, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37078724

RESUMO

Black phosphorene has attracted widespread attention because of its great potential as a high-performance anode material for sodium-ion batteries (SIBs). However, almost all theoretical studies on sodium (Na) atom adsorption and diffusion in it have not taken temperature into account. Actually, the structural stability of an anode material at room temperature is vital in practical applications. In this work, employing first-principles calculations, we investigate the stability of AA-, AB-, AC- and AD-stacked bilayered black phosphorene (BBP) at ground state, and Na adsorption and diffusion within BBPs. Using ab initio molecular-dynamics (AIMD) calculations, dynamic stabilities of pristine BBP and Na-adsorbed BBP systems at room temperature are discussed. Our calculations show that only AB-stacked BBP is stable. Na atoms generally prefer to intercalate within BBP, making all BBPs exhibit metallic properties, which provides good electrical conductivity required for an ideal anode of SIBs. In particular, our AIMD results indicate that the temperature effect on the structural stability of Na-adsorbed BBP could not be neglected. It increases Na capacity loss at room temperature. This provides an important reference for further theoretical and experimental exploration of anode materials for SIBs. Additionally, the AC-stacked structure facilitates Na intercalation within BBP, and Na diffusion exhibits a strong directional preference, diffusing very fast along the zigzag direction. Our results suggest that AC-stacked BBP is a potential anode material of SIBs.

9.
Phys Chem Chem Phys ; 24(28): 17337-17347, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35819058

RESUMO

AEIn2As2 (AE = Ca, Sr, Ba), as a new crucial nonmagnetic thermoelectric candidate, needs to be understood in terms of its potential electronic structure properties and topological characteristics in both experimental and theoretical studies. Here we report that AEIn2As2 with Zintl phases will undergo insulator-metal phase transition and topological quantum phase transition under pressure modulation based on first-principles calculations. Firstly, band inversion occurred between the In(As)-s and As(In)-p states in the structures of AEIn2As2 with the P63/mmc space group in the absence of pressure and identified that they are all non-trivial topological insulators. Next, Bader charge and AIM topology analysis elucidate the nature of pressure-induced chemical bond enhancement. Lastly, we have discovered pressure-controllable band gap closure while the topologically protected surface states disappear, realizing insulator-metal phase transition and topological quantum phase transition. Our research not only enriches the family of topological insulators but also provides a good platform for the study of thermoelectric properties.

10.
Clin J Sport Med ; 32(6): 608-616, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36315820

RESUMO

OBJECTIVE: The objective of this review was to analyze the effect of arthroscopic surgery for femoroacetabular impingement syndrome (FAI) in adolescents and factors that may influence the revision rate. DESIGN: Systematic review and meta-analysis. SETTING: PubMed, Scopus, Cochrane Library, EMBASE, and MEDLINE were searched from their earliest records to May 2021. PATIENTS: Adolescents who underwent primary arthroscopic treatment for FAI. INTERVENTIONS: Hip arthroscopic treatment. MAIN OUTCOME MEASURES: Patient-reported outcomes (PROs), alpha angle, revision rates, and the rate of complications. RESULTS: A total of 832 hips in 753 patients were included in this study. All PROs improved significantly. The modified Harris Hip Score pooled mean difference was 24.99 (95% CI, 22.88-27.10, P < 0.0001, I2 = 19.9%), Hip Outcome Score (HOS)-Sports-Specific Subscale was 35.88 (95% CI, 33.07-38.68, P < 0.0001, I2 = 0%), HOS-Activities of Daily Living was 23.53 (95% CI, 21.21-25.85, P < 0.0001, I2 = 0%), and the Nonarthritic Hip Score was 22.34 (95% CI, 18.40-26.28, P < 0.0001, I2 = 40.9%). The visual analog scale for pain decreased by 40.39 (44.39-36.40, P < 0.0001, I2 = 0%). The alpha angle decreased by 22.0 degrees from 62.9 degrees to 40.9 degrees after arthroscopic surgery. The rate of complication and revision surgery was 1.2% (10/832) and 3.4% (28/832), respectively, with high postoperative patient satisfaction. CONCLUSIONS: All PROs significantly improved after surgery, with a low rate of complications and reoperation. High postoperative patient satisfaction was also reported.


Assuntos
Impacto Femoroacetabular , Humanos , Adolescente , Impacto Femoroacetabular/cirurgia , Atividades Cotidianas , Articulação do Quadril/cirurgia , Resultado do Tratamento , Artroscopia , Seguimentos
11.
Small ; 17(25): e2100538, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34032372

RESUMO

Carbonaceous materials exhibit promising application in electrochemical energy storage especially for hollow or porous structure due to the fascinating and outstanding properties. Although there has been achieved good progress, controllable synthesis of hollow or porous carbons with uniform morphology by a green and easy way is still a challenge. Herein, a new artful and green approach is designed to controllably prepare hollow porous carbon materials with the assistance of boron oxide vitreum under a relatively low temperature of 500 °C. The vitreous B2 O3 provides a flowing carbonization environment and acts as etching agent accompanying with boron doping. By this general strategy, hollow and porous carbon architectures with various morphology of spheres and hollow polyhedrons are successfully fabricated by metal organic framework (MOF) precursors. Furthermore, such hollow carbon materials exhibit considerably excellent Na+ /K+ storage properties through enhanced capacitive behavior due to due to the highly porous structure and large surface area. It is notable that hollow carbon spheres display nearly 90% initial Coulombic efficiency, outstanding rate capability with 130 mAh g-1 at 30 A g-1 and long cycling life for sodium ion storage.

12.
Small ; 17(8): e2006373, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33522133

RESUMO

Up to now, the silicon-graphite anode materials with commercial prospect for lithium batteries (LIBs) still face three dilemmas of the huge volume effect, the poor interface compatibility, and the high resistance. To address the above challenges, micro-nano structured composites of graphite coating by ZnO-incorporated and carbon-coated silicon (marked as Gr@ZnO-Si-C) are reasonably synthesized via an efficient and convenient method of liquid phase self-assembly synthesis combined with annealing treatment. The designed composites of Gr@ZnO-Si-C deliver excellent lithium battery performance with good rate performance and stable long-cycling life of 1000 cycles with reversible capacities of 1150 and 780 mAh g-1 tested at 600 and 1200 mA g-1 , respectively. The obtained results reveal that the incorporated ZnO effectively improve the interface compatibility between electrolyte and active materials, and boost the formation of compact and stable surface solid electrolyte interphase layer for electrodes. Furthermore, the pyrolytic carbon layer formed from polyacrylamide can directly improve electrical conductivity, decrease polarization, and thus promote their electrochemical performance. Finally, based on the scalable preparation of Gr@ZnO-Si-C composites, the pouch full cells of Gr@ZnO-Si-C||NCM523 are assembled and used to evaluate the commercial prospects of Si-graphite composites, offering highly useful information for researchers working in the battery industry.

13.
Phys Chem Chem Phys ; 22(7): 3867-3874, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32026893

RESUMO

Using first-principles calculations based on density functional theory, we systematically investigated the electronic properties and charge transfer of topological insulator Bi2Te3-xSex thin films under an external electric field. As the selenium content in Bi2Te3-xSex thin films increases, the band gap is gradually opened, with changes in the charge distribution. In addition, the experimentally stable Bi2Te2Se and Bi2Se2Te thin films are extremely robust under vertical electric fields up to 0.2 V Å-1. The electronic structures of Bi2Te2Se and Bi2Se2Te thin films are insensitive to the electric fields and exhibit only a Rashba-like splitting pattern near the Fermi level. Remarkably, the charge transfer in Bi2Te2Se and Bi2Se2Te thin films under an external electric field is suppressed. We found that the robustness characteristic is inextricably linked to the strong covalent bonding of tellurium and bismuth atoms. These results indicated that Bi2Te2Se and Bi2Se2Te thin films are robust to the internal electrical field during growth on the substrate, which is beneficial for experimental studies as well as for the potential applications of spintronic devices.

14.
Small ; 15(18): e1900436, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30957424

RESUMO

For Si anode materials used for lithium ion batteries (LIBs), developing an effective solution to overcome their drawbacks of large volume change and poor electronic conductivity is highly desirable. Here, the composites of ZnO-incorporated and carbon-coated silicon/porous-carbon nanofibers (ZnO-Si@C-PCNFs) are designed and synthesized via a traditional electrospinning method. The prepared ZnO-Si@C-PCNFs can obviously overcome these two drawbacks and provide excellent LIB performance with excellent rate capability and stable long cycling life of 1000 cycles with reversible capacity of 1050 mA h g-1 at 800 mA g-1 . Meanwhile, anodes of ZnO-Si@C-PCNFs attached with Ag particles display enhanced LIB performance, maintaining an average capacity of 920 mA h g-1 at a large current of 1800 mA g-1 even for 1000 cycles with negligible capacity loss and excellent reversibility. In addition, the assembling method with important practical significance for a simple pouch full cell is designed and used to evaluate the active materials. The Ag/ZnO-Si@C-PCNFs are prelithiated and assembled in full cells using LiNi0.5 Co0.2 Mn0.3 O2 (NCM523) as cathodes, exhibiting higher energy density (230 W h kg-1 ) of 18% than that of 195 W h kg-1 for commercial graphite//NCM523 full pouch cells. Importantly, the comprehensive mechanisms of enhanced electrochemical kinetics originating from ZnO-incorporation and Ag-attachment are revealed in detail.

15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(5): 1328-33, 2016 May.
Artigo em Zh | MEDLINE | ID: mdl-30001000

RESUMO

The precursor solution is sent to the ultrasonic nozzle directly through a needle tube to prepare Zn1-xCrxO (x=0, 0.01, 0.03 and 0.05)films on quartz substratesby ultrasonic spray method. The structures, optical and magnetic properties of the films were measured by X-ray diffracmeter(XRD), scanning electron microscope(SEM), fluorescence spectrometer, ultraviolet-visible light detector, vibrating sample magnetometer (VSM) and so on. The experimental results indicate that, the undopedZnO thin films exhibit the hexagonal wurtzite crystalline structure with a preferential orientation of (002); the Cr doping restrains the preferred orientation of C axis; the average grain sizes of the samples increase withCr doping, and thesize attains the maximum(31.4 nm) when x=3%. The SEMimages show that the Zn1-xCrxO (x=0, 0.01, 0.03 and 0.05) films are grain-like particles. And it exhibits a long strip shape when x=5%. Moreover, the doping of Cr makes the photoluminescence (PL) spectra of Zn1-xCrxO films change evidently. The undoped sample shows an ultraviolet emission peak at 378 nm as well as a defect related green peak at around 550 nm. However, for the doping samples, there is only a wide range of emission peak from 350 to 550 nm. By gaussian fitting,it is found that VZn, Zni and V-Zn defects exist in the Cr doping films, and VZn is largest when x=3%. The band gap increases with the doping of Cr, and reaches the maximum when x=3%. The doping of Cr hasthe band gap of the samples increase, and the band gapreachs themaximum(3.37 eV) when x=3%. Magnetic measured results show that threedoping samples Zn1-xCrxO(x=1%, 3% and 5%) are ferromagnetic at room temperature, and the magnetization of Zn1-xCrxO (x=3%) is the largest, which is corresponding to the most VZn defect. The experimental results also prove the the oretical prediction that the substitutive Cr in the oxidation state of +3 and the neutral Zn vacancy in the ZnO∶Cr sample are the most favorable defect complex to maintain a high stability of ferromagnetic order.

16.
Phys Chem Chem Phys ; 16(16): 7441-7, 2014 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-24626818

RESUMO

Anatase TiO2 mesocrystals and single crystals with dominant {101} facets were successfully synthesized without any additives using titanate nanowires as precursors under solvothermal and hydrothermal conditions, respectively. It is proposed that the oriented self-assembly process for the formation of TiO2 mesocrystals was controlled by the same thermodynamic principle as that of single crystals in this simple reaction system. Furthermore, the TiO2 mesocrystals were applied in photoelectrochemical (PEC) water splitting and demonstrated much enhanced photocurrent, almost 191% and 274% compared with that of TiO2 single crystals and commercial P25, respectively. Electrochemical impedance measurements under illumination revealed that the photocurrent increase was largely ascribed to the effective charge separation of electron-hole pairs and fast interfacial charge transfer. This could be attributed to the intrinsic characteristics of the mesostructured TiO2 composed of highly oriented nanocrystal subunits offering few grain boundaries, nanoporous nature and a short transport distance.

17.
J Colloid Interface Sci ; 679(Pt A): 694-704, 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39388955

RESUMO

Na3V2(PO4)3 (NVP) is one of the most promising cathode materials for sodium-ion batteries (SIBs) due to its robust three-dimensional framework, high tunability, and relatively high Na+ intercalation potentials. However, its utility is generally constrained by low conductivity, inefficient charge transfer, and subpar interface kinetics. This work presents an efficient and simple method to address these issues. We innovatively modified the NVP surface with Pr6O11 nanoparticles, a negative temperature coefficient (NTC) thermosensitive material, to enhance interface compatibility with electrolytes and improve conductivity. This modification significantly enhances the overall sodium-ion storage performance. Specifically, the optimized NVP-2 %Pr6O11 electrode exhibits excellent electrochemical properties with the aid of an optimized conductivity network compared to the unmodified NVP. Cycled at an 8C current density, the NVP-2 %Pr6O11 electrode achieves high specific capacities of 102.6 mAh·g-1 at 27 °C and 95.6 mAh·g-1 at 45 °C. After 1000 cycles, the capacity retention rates are 81.18 % and 78.97 %, respectively, significantly higher than the 20.59 % and 14.99 % of pure NVP. In coin full-battery testing, the NVP-2 %Pr6O11 electrode retains 89.76 % capacity after 500 cycles at 8C. In addition, the assembled The NVP-2 %Pr6O11//HC pouch full battery exhibits better sodium-ion storage and thermal safety performance compared to the NVP-SP//HC battery. This simple modification strategy provides an effective insight into the application of NVP electrodes in energy storage.

18.
RSC Adv ; 14(6): 3962-3971, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38288147

RESUMO

PbPdO2, a gapless semiconductor, can be transformed into a spin gapless semiconductor structure by magnetic ion doping. This unique band-gap structure serves as the foundation for its distinctive physical properties. In this study, PbPd1-xMnxO2 (x = 0.05, 0.1, 0.15) thin films with (002) preferred orientation were prepared by laser pulse deposition (PLD). The structural, electroresistive and magnetoresistive properties were systematically characterized, and the results suggest that films with different Mn doping ratios exhibit a current-induced positive colossal electroresistance (CER), and the CER values of PbPd1-xMnxO2 thin films increase with the increase of Mn doping concentration. The CER values are several fold magnitudes higher compared to those of the previously reported PbPdO2 films possessing identical (002) orientation. Combined with first-principles calculation, the underlying influence mechanism of Mn doping on CER is elucidated. In situ X-ray photoelectron spectroscopy (XPS) demonstrates a close correlation between the positive CER and the band gap change induced by oxygen vacancies in PbPd1-xMnxO2. Additionally, it is observed that Mn-doped films exhibit weak localization (WL) and weak anti-localization (WAL) quantum transport. Moreover, it is found that Mn doping can lead to a transition from WAL to WL; a small amount of Mn doping significantly enhances the weak anti-localization effect. However, with increasing Mn concentration, the WAL effect is conversely weakened. The results of studies suggest strongly that PbPdO2, one of the few oxide topological insulators, can display novel quantum transport behavior by ion doping.

19.
J Colloid Interface Sci ; 676: 603-612, 2024 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-39053408

RESUMO

The widespread application of Li4Ti5O12 (LTO) anode in lithium-ion batteries has been hindered by its relatively low energy density. In this study, we investigated the capacity enhancement mechanism of LTO anode through the incorporation of Na+ cations in an Li+-based electrolyte (dual-cation electrolyte). LTO thin film electrodes were prepared as conductive additive-free and binder-free model electrodes. Electrochemical performance assessments revealed that the dual-cation electrolyte boosts the reversible capacity of the LTO thin film electrode, attributable to the additional pseudocapacitance and intercalation of Na+ into the LTO lattice. Operando Raman spectroscopy validated the insertion of Li+/Na+ cations into the LTO thin film electrode, and the cation migration kinetics were confirmed by ab initio molecular dynamic (AIMD) simulation and electrochemical impedance spectroscopy, which revealed that the incorporation of Na+ reduces the activation energy of cation diffusion within the LTO lattice and improves the rate performance of LTO thin film electrodes in the dual-cation electrolyte. Furthermore, the interfacial charge transfer resistance in the dual-cation electrolyte, associated with ion de-solvation processes and traversal of the cations in the solid-electrolyte interphase (SEI) layer, are evaluated using the distribution of relaxation time, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Our approach of performance enhancement using dual-cation electrolytes can be extrapolated to other battery electrodes with sodium/lithium storage capabilities, presenting a novel avenue for the performance enhancement of lithium/sodium-ion batteries.

20.
J Phys Condens Matter ; 35(40)2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37336210

RESUMO

The exceptional porous architecture of graphdiyne (GDY) renders it a potential candidate for magnetic storage media. This paper delves into the magnetic properties of GDY doped with 5d transition metal (TM) atoms via first-principles calculations. Our results divulge the stable embedding of these TM atoms within the triangular cavities of GDY, yielding a significant magneto-crystal anisotropy energy. In particular, Ta@GDY exhibits a remarkable magneto-crystal anisotropy energy value of 11.72 meV. By introducing TM atoms at the top, one could significantly change the magneto-crystal anisotropy energy value of the system, subsequently flipping the easy magnetization axis. The MAE values of Os-W3@GDY and Re-Ir3@GDY are -21.60 meV and -41.68 meV, which are expanded by a factor of 4 and 6 compared to those before the introduction of the top atom. Furthermore, we observed that the magneto-crystal anisotropy energy value of Ta@GDY is modulated by strain. Our research uncovers GDY as a promising substrate for two-dimensional magnetic materials that could be exploited in forthcoming magnetic memory devices.


Assuntos
Grafite , Anisotropia , Fenômenos Físicos , Fenômenos Magnéticos
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