Publications by authors named "Zi-Feng Ma"

The low power density has emerged as a pivotal challenge impeding the broader application of fluorinated carbon (CF). Herein, a strategy for the fabrication of MXene@PS@CF electrodes is proposed through electrostatic self-assembly. The method leverages polystyrene (PS) microspheres as a sacrificial template to introduce MXene onto the CF surface via electrostatic interactions.

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  • * A new synthesis method using molten salt introduces gradient pores in the NCM particles, helping to absorb volume changes and reduce fractures, thus improving the cathode's performance.
  • * This approach leads to a high nickel, low cobalt cathode that shows both excellent energy capacity (941.2 Wh/kg) and impressive stability, maintaining 80.5% capacity after 800 cycles and over 95% after storage at high temperatures.
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  • Silica (SiO) is a promising anode material for lithium-ion batteries due to its low cost and high theoretical capacity, but struggles with low electrochemical activity and volume expansion.
  • To overcome these issues, SiO is coated with CoO and combined with graphene sheets to create a uniform and effective anode composite material (SiO@CoO/GS).
  • This new composite shows a high reversible capacity of 738 mA h/g after 500 cycles and excellent rate performance, attributed to the activation of SiO by Co-metal and strong interactions with graphene.
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Unstable cathode/electrolyte interphase and severe interfacial side reaction have long been identified as the main cause for the failure of layered oxide cathode during fast charging and long-term cycling for rechargeable sodium-ion batteries. Here, we report a superionic conductor (NaV(PO), NVP) bonding surface strategy for O3-type layered NaNiFeMnO (NFM) cathode to suppress electrolyte corrosion and near-surface structure deconstruction, especially at high operating potential. The strong bonding affinity at the NVP/NFM contact interface stabilizes the crystal structure by inhibiting surface parasitic reactions and transition metal dissolution, thus significantly improving the phase change reversibility at high desodiation state and prolonging the lifespan of NFM cathode.

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Semi-solid lithium-ion batteries (SSLIBs) based on "slurry-like" electrodes hold great promise to enable low-cost and sustainable energy storage. However, the development of the SSLIBs has long been hindered by the lack of high-performance anodes. Here the origin of low initial Coulombic efficiency (iCE, typically <60%) is elucidated in the graphite-based semi-solid anodes (in the non-flowing mode) and develop rational strategies to minimize the irreversible capacity loss.

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The LiNiMnCoO (NMC811) cathode material has been of significant consideration owing to its high energy density for Li-ion batteries. However, the poor cycling stability in a carbonate electrolyte limits its further development. In this work, we report the excellent electrochemical performance of the NMC811 cathode using a rational electrolyte based on organic ionic plastic crystal -ethyl--methyl pyrrolidinium bis(fluorosulfonyl)imide Cmpyr[FSI], with the addition of (1:1 mol) LiFSI salt.

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Na MnV(PO ) /C (NMVP) has been considered an attractive cathode for sodium-ion batteries with higher working voltage and lower cost than Na V (PO ) /C. However, the poor intrinsic electronic conductivity and Jahn-Teller distortion caused by Mn inhibit its practical application. In this work, the remarkable effects of Zr-substitution on prompting electronic and Na-ion conductivity and also structural stabilization are reported.

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  • Magnesium-sulfur (Mg-S) batteries are gaining attention as a cheaper and more efficient alternative to lithium-ion batteries, but they face challenges, particularly the shuttle effect causing performance issues.
  • Researchers developed a new separator using copper phosphide (CuP) to improve the adsorption of polysulfides and enhance the chemical reactions necessary for stable battery operation.
  • Tests show that this innovation allows Mg-S batteries to achieve a high specific capacity, rapid charge rates, long cycle life, and stable performance even at higher temperatures.
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A micro-cubic Prussian blue (PB) with less coordinated water is first developed by electron exchange between graphene oxide and PB. The obtained reduced graphene oxide-PB composite exhibited increased redox reactions of the Fe sites and delivered ultrahigh specific capacity of 163.3 mA h g (30 mA g) as well as excellent cycle stability as a cathode in sodium-ion batteries.

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Retraction of 'Prussian blue without coordinated water as a superior cathode for sodium-ion batteries' by Dezhi Yang , , 2015, , 8181-8184, https://doi.org/10.1039/C5CC01180A.

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O3-Type layered oxides are widely studied as cathodes for sodium-ion batteries (SIBs) due to their high theoretical capacities. However, their rate capability and durability are limited by tortuous Na diffusion channels and complicated phase evolution during Na extraction/insertion. Here we report our findings in unravelling the mechanism for dramatically enhancing the stability and rate capability of O3-NaNiMnSbO (NaNMS) by substitutional Sb doping, which can alter the coordination environment and chemical bonds of the transition metal (TM) ions in the structure, resulting in a more stable structure with wider Na transport channels.

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Aims And Objectives: To establish a simple score that enables nurses to quickly, conveniently and accurately identify patients whose condition may change during intrahospital transport.

Background: Critically ill patients may experience various complications during intrahospital transport; therefore, it is important to predict their risk before they leave the emergency department. The existing scoring systems were not developed for this population.

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Sodium-ion batteries (SIBs) are on the verge of achieving practical applications, and the key is to find suitable electrode materials. The polyanionic iron-based material NaFe(PO) (NFPO) possesses an open three-dimensional framework structure with good thermal stability and is regarded as an outstanding cathode material for SIBs. Nevertheless, its poor electrical conductivity, problems with erosion of electrolytes, and structural deterioration during cycling still need to be urgently addressed.

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Rechargeable battery technologies have revolutionized electronics, transportation and grid energy storage. Many materials are being researched for battery applications, with layered transition metal oxides (LTMO) the dominating cathode candidate with remarkable electrochemical performance. Yet, daunting challenges persist in the quest for further battery developments targeting lower cost, longer lifespan, improved energy density and enhanced safety.

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  • Single-crystalline nickel-rich cathodes show promise for high-energy lithium-ion batteries due to their greater structural and chemical stability compared to polycrystalline materials.
  • Lattice strain and defects within these cathodes significantly affect their intercalation chemistry and overall electrochemical performance.
  • Using a theoretical model, we found that recovering lost capacity through thermal treatment depends on the cathode's composition and state of charge, which could help improve the longevity of lithium-ion batteries.
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Background: Tuberculosis (TB) caused Mycobacterium tuberculosis (M.tb) is one of infectious disease that lead a large number of morbidity and mortality all over the world. Although no reliable evidence has been found, it is considered that combining chemotherapeutic drugs with Chinese herbs can significantly improves the cure rate and the clinical therapeutic effect.

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  • A one-step solvothermal method was used to synthesize copper sulfide with two different shapes: flower-like (f-CuS) and carambola-like (c-CuS).
  • f-CuS showed superior performance as a cathode catalyst in lithium-oxygen batteries, featuring faster reaction rates and better overall battery performance compared to c-CuS.
  • The study also included theoretical calculations to explain the varying performances of the two morphologies, highlighting that CuS can act as both a solid and liquid catalyst in the battery system.
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Iron phosphide with high specific capacity has emerged as an appealing candidate for next-generation lithium-ion battery anodes. However, iron phosphide could undergo conversion reactions and generally suffer from a rapid capacity degradation upon cycling due to its structure pulverization. Chemomechanical breakdown of iron phosphide due to its rigidity has been a challenge to fully realizing its electrochemical performance.

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Constructing a rational electrode structure for supercapacitors is critical to accelerate the electrochemical kinetics process and thus promote the capacitance. Focusing on the flexible supercapacitor electrode, we synthesized a three-dimensional (3D) porous polypyrrole (PPy) film using a modified vapor phase polymerization method with the use of a porous template (CaCO). The porous design provided the PPy film with an improved surface area and pore volume.

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The advancement of novel synthetic approaches for micro/nanostructural manipulation of transition metal phosphide (TMP) materials with precisely controlled engineering is crucial to realize their practical use in batteries. Here, we develop a novel spray-drying strategy to construct three-dimensional (3D) N,P co-doped graphene (G-NP) microspheres embedded with core-shell CoP@C and MoP@C nanoparticles (CoP@C⊂G-NP, MoP@⊂G-NP). This intentional design shows a close correlation between the microstructural G-NP and chemistry of the core-shell CoP@C/MoP@C nanoparticle system that contributes towards their anode performance in lithium-ion batteries (LIBs).

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Objectives: The aim of this study was to assess the value of the National Early Warning Score and Worthing Physiological Scoring System for predicting changes in the condition of critical cases during transfer from the emergency department to the intensive care unit.

Methods: This prospective single-centre study was conducted at a 1759-bed hospital in Beijing. We recorded the vital signs in the cases before leaving the emergency department and their changes in condition during transit.

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P2-NaNiMnO presents high working voltage with a theoretical capacity of 173 mAh g. However, the lattice oxygen on the particle surface participates in the redox reactions when the material is charged over 4.22 V.

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Heterogeneous electrocatalytic reactions only occur at the interface between the electrocatalyst and reactant. Therefore, the active sites are only necessary to be distributed on the surface of the electrocatalyst. Based on this motivation, here, we demonstrate a systematic study on surface tuning for a carbon-based electrocatalyst from metal-free (with the heteroatoms N and S, NS/C) to metal-containing surfaces (with Co, N, and S, CoNS/C).

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High temperature proton exchange membrane fuel cells (HT-PEMFCs) are one type of promising energy device with the advantages of fast reaction kinetics (high energy efficiency), high tolerance to fuel/air impurities, simple plate design, and better heat and water management. They have been expected to be the next generation of PEMFCs specifically for application in hydrogen-fueled automobile vehicles and combined heat and power (CHP) systems. However, their high-cost and low durability interposed by the insufficient performance of key materials such as electrocatalysts and membranes at high temperature operation are still the challenges hindering the technology's practical applications.

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