Yongming Zhu

Harbin Institute of Technology | HIT · Department of Chemical Engineering

X-ray nano-computed tomography (nano-CT) and deep learning combined with Cs-corrected scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy were employed to investigate the atomic to microscopic structural evolution of LiNi0.8Co0.1Mn0.1O2 (NCM) upon cycling at 55 °C. Two types of intergranular cracks were clearly di...

A Co-free LiNiO2 (LNO) cathode material with high reversible capacity and low cost is promising for applications in lithium-ion batteries; however, it suffers from severe polarization increase and stress accumulation induced cracks, limiting its commercial applications. We investigate structural, electrochemical cycling, and lithium-ion diffusion p...

Ni-Co-Mn (NCM) ternary cathode material has developed rapidly in the electric vehicle industry due to its quite low price and high-energy density. However, its practical application is limited due to serious electrochemical performance degradation and thermal instability in long-term cycle. To address such issues, Nb doping nickel-rich monocrystal...

Lithium-rich manganese layered oxide (LLMO) materials are one of the key materials for high energy density lithium ion batteries, but the loss of lattice oxygen during cycling leads to the increase of lithium ion transport resistance and the deterioration of material properties. In this study, density functional theory is used to calculate the form...

Catalysts with high stability and efficient electrocatalytic properties are urgently explored to improve sluggish kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in Li-O2 batteries. In this paper, exquisitely designed bifunctional catalyst comprising Co3O4 nanospheres embedded in NiO nanosheet arrays on carbon cl...

The cathodes of LiNiO2 (LNO), Li[Ni0.9Mn0.1]O2 (LNM91) and the concentration gradient material Li[Ni0.9Mn0.1]O2 (G-LNM91) were synthesized by co-precipitation method, and SEM, XRD, TEM and electrochemical tests were performed. SEM images show that the primary needle-like particles on spherical surface of the gradient G-LNM91 are the densest. The re...

We present a green and scalable chemical blowing strategy toward the mass production of two-dimensional (2D) P, N, S-codoped carbon nanosheets incorporated with CoP nanoparticles ([email protected]) through annealing a gel precursor. And the precursor is simply prepared via the gelation reaction among Co²⁺, L-cysteine (LC), and phytic acid (PA). It...

Nickel-rich layered LiNi0.8Co0.1Mn0.1O2 is a promising cathode material due to its high specific capacity. However, commercial application of this material is impeded by its rapid capacity degradation associated with structural instability. In this work, 0.5–2 mol% Nb5+ doped LiNi0.8Co0.1Mn0.1O2 cathode material is prepared by heat treatment of a m...

NCM811 precursor with concentration gradients is prepared by adjusting the feeding method of MnSO4·H2O in the co-precipitation method. X-ray diffraction patterns show that the precursors have good crystal structure of β-Ni(OH)2. Energy dispersive X-ray spectroscopy shows that the precursor sample performs relatively gentle concentration gradient di...

The commercialization of layered lithium-rich manganese oxide material (LLMO) suffers from low conductivity, poor cycling performance, and complicated synthetic techniques. Herein, we develop a low-cost, short-time, and simple low-temperature combustion synthesis (LCS) method for massive production of spherical LLMO material with high oxygen vacanc...

Zinc manganese oxide (ZMO) system represents a notable family of mixed transition metal oxides (MTMOs) because of their superiority of the high theoretical capacity, adequacy of natural content, and low cost. However, the methods to match both the reliable synthesis and the designable construction of large-sized two-dimensional (2D) ZMO nanosheets...

In order to reduce the vanadium ion permeability while still keep its high stability, atom radical polymerization (ATRP) method was used to introduce zwitterionic sulfobetaine methacrylate (SBMA) onto the Nafion matrix in homogenous solution. The Nafion-grafted poly SBMA (N-g-PSBMA) solution was then used to blend with common Nafion solution to pre...

The mathematical model of lithium iron phosphate prepared by hydrothermal method was established by factor experimental design. The effect of individual variables and their interactions were studied by the main effects plot and Interaction plot. The influence of ascorbic acid dosage on the discharge specific capacity was greater than the hydrotherm...

A facile one-step hydrothermal method has been adopted to directly synthesize the CuCo2S4 material on the surface of Ni foam. Due to the relatively large specific surface area and wide pore size distribution, the CuCo2S4 material not only effectively increases the reactive area, but also accommodates more side reaction products to avoid the difficu...

Li–oxygen battery provides much higher specific energy density compared to conventional Li–ion batteries, but there is a lack of desired cathodes which show lower over-potential during the charging cycle. Here, we report the effect of surface morphology of carbon-free spinel-like NiCo2O4 nanowires and nanosheets on Ni foam on cathode performance in...

Lithium-rich material 0.5Li 2 MnO 3 ·0.5LiNi 1/3 Co 1/3 Mn 1/3 O 2 is successfully prepared by a co-precipitation method. Electrochemical impedance spectroscopy (EIS)is measured under various charge/discharge voltages in the first and second cycles. A reasonable equivalent circuit model is designed for EIS analysis and the fitting curves are aligne...

In this work, we have realized the synchronous and large-scale synthesis of one-dimensional (1D) carbon nanotubes (CNTs) on two-dimensional (2D) N-doped carbon nanosheets (NCNS) by a one-step annealing of Ni-containing gel precursor. Upon heating, the gel is “blown” into large-sized 2D NCNS with uniformly embedded Ni nanoparticles that can catalyze...

Li1.2Ni0.133Co0.133Mn0.534O2/graphene composites are prepared with Li1.2Ni0.133Co0.133Mn0.534O2 particles and graphene oxide sol by a novel ethanol solution reduction method and an ethanol solvothermal method. The structure and morphology are characterized by X-ray diffraction, Raman spectra, scanning electron microscope, and transmission electron...

Nitrogen–phosphorus co-doped nanoscale carbon coating (N/P–C) was constructed on the surface of LiNi0.8Co0.15Al0.05O2 (NCA). The coated material showed a shell–core structure, the core layer was NCA, the shell layer was N/P–C, and the coating was evenly distributed on the surface of the material. The coating improves electron transport path in the...

Two different carbon sources, sucrose and glucose, were used as raw materials for constructing a nanoscale carbon coating on the surface of LiNi0.8Co0.15Al0.05O2 (NCA). They were mixed with a certain mass ratio and then were annealed to form a nanoscale even coating, which showed a [email protected] shell-core structure. The core layer was NCA and...

How to solve the crossover of vanadium ions through ion exchange membrane is a key issue in vanadium redox flow battery (VRB), especially for ultra-thin membranes used for VRB to obtain a lower cell resistance. Herein, an ultra-thin (~ 30 μm) PTFE/SPEEK [polytetrafluoroethylene/sulfonated poly(ether ether ketone), P/S] membrane is successfully prep...

The electron transfer failure model is proposed to analyze the effects of discharge products on the air electrode performance in lithium-air batteries. In order to understand how the air electrode products are obtained during the discharge cycle, three kinds of carbon-based air electrode are constructed, and discharged products are analyzed by powd...

Nickel-cobalt bimetallic sulfide (NiCo2S4) has a typical AB2O4 spinel structure. The conductivity of NiCo2S4 is two orders of magnitude higher than that of NiCo2O4, and its conductivity is 1.25×10⁶ S·m⁻¹at room temperature. In addition, NiCo2S4 provides a more efficient redox reaction than the corresponding one-component sulfide, and has great pote...

Blend membranes of quaternized polysulfone/polyvinylidene fluoride (Q/P) for all vanadium redox flow battery (VRFB) are prepared by one-step solution casting method to reduce the vanadium permeation and improve the mechanical properties of pure quaternized polysulfone membrane. The physicochemical properties and electrochemical performances of the...

MnO2 doped with Ce was hydrothermally synthesized and the as-made breathable waterproof membrane used outside the cathode was prepared for improving the lithium-air battery performance in air. The samples were characterized by scanning electron microscopy (SEM), energy dispersive spectrum analysis (EDS), charge–discharge cycle tests, charge–dischar...

Spherical nickel rich layer cathode materials (LiNi0.85-xCo0.15AlxO2 (x = 0.02, 0.05 and 0.10), NCA) with excellent electrochemical performance for high energy densities lithium-ion batteries are successfully synthesized by a continuous co-precipitation method. An elaborate design of Al solution with sodium aluminate is successfully adopted, which...

The Cover shows a new carbon nanofiber codoped with nitrogen and phosphorus (NPCNF) that was fabricated by pyrolysis of phytic acid doped polyaniline aerogel. The NPCNF shows an extremely high discharge capacity and good catalytic activity towards the oxygen reduction reaction as oxygen electrodes in nonaqueous Li-O2 batteries.In their Full Paper,...

A novel carbon nanofiber co-doped with nitrogen and phosphorus (NPCNF) that has a high specific surface area with good electrocatalytic properties for oxygen reduction reaction (ORR) was synthesized using a template-free method. The fabricated processes involve the pyrolysis of phytic acid doped polyaniline aerogel. A nonaqueous Li-O2 battery with...

Layered LiNi0.8Co0.15Al0.05O2 cathode materials have been synthesized by co-precipitation methods. The effect of pre-thermal treatment was investigated by thermogravimetric differential thermal analysis. Although X-ray diffraction has confirmed that all diffraction peaks in XRD patterns for samples treated at 500 ~ 750 °C can be a well-indexed hexa...

Rodlike manganese oxide (α-MnO2) was prepared through a homogeneous hydrothermal reaction. Air electrodes, made with a mixture of graphite/acetylene black (G/AB) with and without the as-made α-MnO2, were prepared for lithium–air cells. Linear sweep voltammetry (LSV) results show that the as-made α-MnO2 can greatly increase the rate of the oxygen re...

The cathode is the most important component of a lithium-ion battery. The olivine structure lithium iron phosphate (LiFePO4) with its numerous appealing features, such as high theoretical capacity, acceptable operating voltage, increased safety, environmental benignity, and low cost, has attracted extensive interest as a potential cathode material...

Amorphous hydrated iron (III) phosphate has been synthesized by a coordinate precipitation method from equimolecular Fe(NO3)3 and (NH4)2HPO4 solutions at an elevated temperature. Hydrated iron (III) phosphate samples and the corresponding LiFePO4/C products were characterized by XRD and SEM. The electrochemical behavior was studied by cyclic voltam...

To reduce the consumption and improve the performance of Nafion, a thin polytetrafluoroethene (PTFE)/Nafion (P/N) composite membrane for vanadium redox flow battery (VRB) application was prepared by impregnating porous PTFE membrane with Nafion solution. The P/N membrane is almost as transparent as commercial Nafion 212 (N212) membrane, which can b...

A new solid-state electrochemical cell for CO2 sensing has been set up using Li3PO4 and Li4SiO4 (LiSiPO) solid electrolyte and Li1-δMn2O4/MnO2 as reference electrode. The electromotive force (EMF), the reproducibility, and the long-term stability of the sensor signals have been examined at temperature between 400 and 500 °C exposure on dry atmosphe...

Li3V2−xSnx(PO4)3/C cathode materials with uniform and fine particle sizes were successfully and fast synthesized by a microwave solid-state synthesis method. X-ray diffraction patterns demonstrated that the appropriate addition of Sn did not destroy the lattice structure of Li3V2(PO4)3/C, but decreased the unit cell volume. X-ray photoelectron spec...

A novel Nafion-sulfonated diphenyldimethoxysilane (N-sDDS) composite membrane is prepared and employed in vanadium redox flow battery (VRB). Ion exchange capacity, proton conductivity, water transport behavior, and the cell performances are characterized. Fourier transform-infrared and X-ray diffraction analysis indicate that the sulfonated dipheny...

SnO2 hollow microspheres were synthesized by a facile template-free hydrothermal method combining with an annealing process, and sodium stannate trihydrate was used as precursor. The diameter of microspheres which were composed of nanoparticles with size of about 10 nm was in the range of 200–500 nm. As anode materials for lithium ion batteries, th...

Nano structure β-MnO 2 is successfully prepared via hydrothermal method, and dopes with LiFePO 4 /C composite compounds. The presence of the β-MnO 2 doping is ascertained with the pine needle liked nano rods mixed with LiFePO 4 /C particles by scanning electron microscopy (SEM). The doped β-MnO 2 does not affect the crystal structure of the LiFePO...

Cu 2 O with S as additive electrode using Ni foam as the substrate is prepared in Mg–Cu 2 O seawater battery. The morphology and electrochemistry performance of electrode are investigated. The excellent electrochemical properties of Ni foam-supported electrode indicate that it is suitable for seawater devices. The cell voltage of Mg–Cu 2 O seawater...

The research progress for improving the properties of lithium metal electrode in rechargeable lithium metal batteries is reviewed. The treatment methods are introduced respectively as follow: either making surface pretreatment on lithium metal, to form better solid electrolyte interface in advance, or producing the protecting coating directly; addi...

Solid lithium ion conducting electrochemical cells using LiSiPO as solid electrolyte and Li2CO3 mixed with Au as electrodes were prepared and employed as chemical sensors for the detection of CO2 gas. The EMF of the cell depends on the concentration of CO2 in air according to the partial pressure dependence of Nernst’s law in the investigated range...

To improve the anticorrosion resistance of chromium-free Zn–Al sintered coating, characteristics of chromate on zinc–aluminum–chromium were studied by electrochemical methods. Depth profiles of elements were obtained by glow discharge spectrum (GDS) and X-ray photoelectron spectroscopy (XPS) was used to analyse the chemical states of main elements...