Varying the amounts of silicon and carbon, different composites have been prepared by ball milling of Si, Ni$_{3.4}$Sn$_4$, Al and C. Silicon and carbon contents are varied from 10 to 30 wt.% Si, and 0 to 20 wt.% C. The microstructural and electrochemical properties of the composites have been investigated by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and electrochemical galvanostatic cycling up to 1000 cycles. Impact of silicon and carbon contents on the phase occurrence, electrochemical capacity and cycle-life are compared and discussed. For C-content comprised between 9 and 13 wt.% and Si-content >= 20 wt.%, Si nanoparticles are embedded in a Ni$_{3.4}$Sn$_4$-Al-C matrix which is chemically homogeneous at the micrometric scale. For other carbon contents and low Si-amount (10 wt.%), no homogeneous matrix is formed around Si nanoparticles. When homogenous matrix is formed, both Ni$_3$Sn$_4$ and Si participate to the reversible lithiation mechanism, whereas no reaction between Ni$_3$Sn$_4$ and Li is observed for no homogenous matrix. Moreover, best cycle-life performances are obtained when Si nanoparticles are embedded in a homogenous matrix and Si-content is moderate (<= 20 wt.%). Composites with carbon in the 9-13 wt.% range and 20 wt.% silicon lead to the best balance between capacity and life duration upon cycling. This work experimentally demonstrates that embedding Si in an intermetallic/carbon matrix allows to efficiently accommodate Si volume changes on cycling to ensure long cycle-life.
In search of high performance anode materials for Mg batteries: computational studies of Mg in Ge, Si, and Sn
我们目前的从头算研究的结构，能量学，和扩散性能的Mg在Si，Ge和Sn金刚石结构，以评估其潜在的插入型阳极材料的镁电池。我们表明，Si可以提供最高的比容量（3817毫安时g-1）和最低的平均插入电压（~0.15 eV vs. Mg）的Mg存储。然而，由于其显著的晶格膨胀百分比（~216%）和缓慢的Mg扩散，Sn和Ge更有吸引力;两种阳极具有比Si更低的晶格膨胀（分别为~ 120%和~ 178%）和扩散势垒（对于单Mg扩散，分别为~0.50和~0.70 eV）。我们表明，镁-镁相互作用在不同阶段的充电可以显着降低扩散势垒相比，单原子扩散，高达0.55 eV。
Sodium ion batteries (SIBs) are considered as an efficient alternative for lithium-ion batteries (LIBs) owing to the natural abundance and low cost of sodium than lithium. In this context, the anode materials play a vital role in rechargeable batteries to acquire high energy and power density. In order to demonstrate transition metal dichalcogenide (TMD) as potential anode materials, we have synthesized MoSeTe sample by conventional flux method, and the structure and morphology are characterized using x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission el…
Silicon is one of the most promising anode materials for Lithium-ion batteries. Silicon endures volume changes upon cycling, which leads to subsequent pulverization and capacity fading. These drawbacks lead to a poor lifespan and hamper the commercialization of silicon anodes. In this work, a hybrid nanostructured anode based on silicon nanoparticles (SiNPs) anchored on vertically aligned carbon nanotubes (VACNTs) with defined spacing to accommodate volumetric changes is synthesized on commercial macroscopic current collector. Achieving electrodes with good stability and excellent electrochemi…
Graphene sponge electrodes were employed for chlorine-free inactivation of Escherichia coli from low conductivity water. The nitrogen-doped reduced graphene oxide (NRGO) sponge anode bearing more positive charge achieved complete E. coli inactivation (i.e., 5 log removal) in the anode-cathode configuration at 115 A m-2, versus 2.6 log removal using boron-doped reduced graphene oxide sponge anode. The bacteria were mainly inactivated via electrosorption and electroporation, as confirmed by the scanning electron microscopy. Storage of the electrochemically treated samples revealed further killin…
Lithium metal cells are key towards achieving high specific energy and energy density for electrification of transportation and aviation. Anode-free cells are the limiting case of lithium metal cells involving no excess lithium and the highest possible specific energy. In addition, anode-free cells are easier, cheaper and safer as they avoid handling and manufacturing of lithium metal foils. Issues related to dendrite growth and poor cycling are magnified in anode-free cells due to lack of excess lithium. Electrolyte and current collector surface play a crucial role in affecting the cycling pe…
Solid-state batteries (SSBs) can offer a paradigm shift in battery safety and energy density. Yet, the promise hinges on the ability to integrate high-performance electrodes with state-of-the-art solid electrolytes. For example, lithium (Li) metal, the most energy-dense anode candidate, suffers from severe interfacial chemomechanical issues that lead to cell failure. Li alloys of In/Sn are attractive alternatives, but their exploration has mostly been limited to the low capacity(low Li content)and In rich Li$_x$In (x$\leq$0.5). Here, the fundamental electro-chemo-mechanical behavior of Li-In a…
Growing energy storage demands on lithium-ion batteries necessitate exploration of new electrochemical materials as next-generation battery electrode materials. In this work, we investigate the previously unexplored electrochemical properties of earth-abundant and tunable Zn1-xSn1+xN2 (x = -0.4 to x = 0.4) thin films, which show high electrical conductivity and high gravimetric capacity for Li insertion. Enhanced cycling performance is achieved compared to previously published end-members Zn3N2 and Sn3N4, showing decreased irreversible loss and increased total capacity and cycle stability. The…
In the present study, a new set of dimensionless coefficients is introduced through non-dimensionalization of electrochemical equations of lead-acid batteries. Non-dimensionalization process has been applied to the electrochemical governing equations including conservation of charge in solid and electrolyte, and conservation of species to derive the non-dimensional model. Four novel dimensionless coefficients of electrode conductivity, electrolyte conductivity, diffusional conductivity of species, and diffusion coefficient are derived from the dimensionless model. The identified model is valid…
The lithium (Li) metal anode is essential for next generation high energy density rechargeable Li metal batteries. Although extensive studies have been performed to prolong the cycle life of Li metal batteries, the calendar life, which associates with chemical corrosion of Li metal in liquid electrolytes, has not been quantitatively understood. Here, by combing the Titration Gas Chromatography (TGC) method and Cryogenic Focused Ion Beam (Cryo-FIB), we established a quantitative relationship between the chemical corrosion rate and electrochemically deposited Li morphology in various liquid elec…
We propose fabrication of the fiber-shaped lithium ion batteries assembled by twisting a cathode filament together with an anode filament. The cathode filament is fabricated by depositing a LiFePO4 (LFP)-composite layer onto a steel-filled polyester conductive thread (SPCT). As anode filaments, we propose several scenarios including a Li4Ti5O12 (LTO)-composite coated SPCT (dip-and-dry deposition), a tin-coated SPCT (PVD deposition) as well as a bare tin wire. An electrolyte composite layer consisting of LiPF6 and polyethylene oxide (PEO) is then deposited onto both the anode and cathode filame…
Batteries are the most abundant form of electrochemical energy storage. Lithium and sodium ion batteries account for a significant portion of the battery market, but high-performance electrochemically active materials still need to be discovered and optimized for these technologies. Recently, tin(II) oxide (SnO) has emerged as a highly-promising battery electrode. In this work, we present a facile synthesis method to produce SnO nanoparticles whose size and shape can be tailored by changing the solvent nature. We study the complex relationship between wet chemistry synthesis conditions and res…
A new experimental approach for in-situ Raman spectroscopy of the electrode | solid electrolyte interfaces in controlled atmospheres, based on the use of optically transparent single-crystal membranes of stabilized cubic zirconia, has been proposed and validated. This technique makes it possible to directly access the electrochemical reaction zone in SOFCs by passing the laser beam through single-crystal electrolyte onto the interface, in combination with simultaneous electrochemical measurements. The case study centered on the analysis of NiO reduction in standard cermet anodes under open-cir…
Thermal electrochemical models for porous electrode batteries (such as lithium ion batteries) are widely used. Due to the multiple scales involved, solving the model accounting for the porous microstructure is computationally expensive, therefore effective models at the macroscale are preferable. However, these effective models are usually postulated ad hoc rather than systematically upscaled from the microscale equations. We present an effective thermal electrochemical model obtained using asymptotic homogenisation, which includes the electrochemical model at the cell level coupled with a the…
All-solid-state Li-ion batteries promise safer electrochemical energy storage with larger volumetric and gravimetric energy densities. A major concern is the limited electrochemical stability of solid electrolytes and related detrimental electrochemical reactions, especially because of our restricted understanding. Here we demonstrate for the argyrodite, garnet and NASICON type solid electrolytes, that the favourable decomposition pathway is indirect rather than direct, via (de)lithiated states of the solid electrolyte, into the thermodynamically stable decomposition products. The consequence …
Li-ion batteries with nickel-manganese-cobalt (NMC) cathode and graphite anode are popularly used in portable electronic devices and electric vehicles. Calendar loss of the lithium ion battery is a dominating factor in battery degradation. However, few modeling work was reported on studying the calendar capacity loss of NMC-graphite Li-ion batteries. In this work, an electrochemical model for NMC-graphite Li-ion battery was developed to investigate its calendar loss behavior. Various factors affecting the calendar loss of the NMC-graphite batteries were systematically investigated, with the re…
Characterizing High-Capacity Janus Aminobenzene-Graphene Anode for Sodium-Ion Batteries with Machine Learning
Google DeepMind（谷歌DeepMind）；BIFOLD -- Berlin Institute for the Foundations of Learning（BIFOLD——柏林学习与数据基础研究所）；Department of Artificial Intelligence, Korea University, Anam-dong, Seongbuk-gu, Seoul 02841, Korea（韩国大学人工智能系）
In search of the potential cathode materials for sodium-ion batteries and to understand the diffusion kinetics, we report the detailed analysis of electrochemical investigation of honeycomb structured Na$_{2}$Ni$_{2}$TeO$_{6}$ material using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), galvanostatic charge-discharge (GCD) and galvanostatic intermittent titration technique (GITT). We found the discharge capacities of 82 and 77 mAhg$^{-1}$ at 0.05~C and 0.1~C current rates, respectively, and the mid-working potential of $\approx$3.9~V at 1~C and high capacity retention …
High-performance anodes for rechargeable Li-ion battery are produced by nanostructuring of the transition metal oxides on a conductive support. Here, we demonstrate a hybrid material of MnO2 directly grown onto fabrics of carbon nanotube fibres, which exhibits notable specific capacity over 1100 and 500 mAh/g at a discharge current density of 25 mA/g and 5 A/g, respectively, with coulombic efficiency of 97.5 %. Combined with 97 % capacity retention after 1500 cycles at a current density of 5 A/g, both capacity and stability are significantly above literature data. Detailed investigations invol…
Sodium-ion batteries (SIBs) have received significant attention as promising alternative for energy storage applications owing to the large availability and low cost of sodium. In this paper we study the electrochemical behavior of Na$_{0.74}$Co$_{1-x}$Nb$_x$O$_2$ ($x=$ 0 and 0.05 samples), synthesized via solid-state reaction. The Rietveld refinement of x-ray diffraction patterns reveals the hexagonal crystal symmetry with P63/mmc space group. The Na$_{0.74}$Co$_{0.95}$Nb$_{0.05}$O$_2$ cathode exhibits a specific capacity of about 91 mAhg$^{-1}$ at a current density of 6 mAg$^{-1}$, whereas N…
Electrochemical performance and diffusion kinetics of a NASICON type Na$_{3.3}$Mn$_{1.2}$Ti$_{0.75}$Mo$_{0.05}$(PO$_4$)$_3$/C cathode for low-cost sodium-ion batteries
Improved Electrochemical Performance and Diffusion kinetics by Boron-doping in Na$_{0.66}$Mn$_{0.8}$Fe$_{0.2}$O$_{2}$ Layered Cathodes for Sodium-Ion Batteries
Indian Institute of Technology Delhi（印度德里理工学院）；Hindu College, University of Delhi（德里大学印度教学院）；Indian Institute of Technology Delhi-Abu Dhabi（印度德里理工学院阿布扎比分校）
Graphene-based sponges doped with atomic nitrogen and boron were applied for the electrochemical degradation of persistent organic contaminants in one-pass, flow-through mode, and in a low-conductivity supporting electrolyte. The B-doped anode and N-doped cathode was capable of >90% contaminant removal at the geometric anodic current density of 173 A m2. The electrochemical degradation of contaminants was achieved via the direct electron transfer, the anodically formed O3, and by the OH radicals formed by the decomposition of H2O2 produced at the cathode. The identified transformation products…
A major bottleneck for the development of Mg batteries is the identification of liquid electrolytes that are simultaneously compatible with the Mg-metal anode and high-voltage cathodes. One strategy to widen the stability windows of current non-aqueous electrolytes is to introduce protective coating materials at the electrodes, where coating materials are required to exhibit swift Mg transport. In this work, we use a combination of first-principles calculations and ion-transport theory to evaluate the migration barriers for nearly 27 Mg-containing binary, ternary, and quaternary compounds span…
Replacing lithium ions with sodium ions as the charge carriers in rechargeable batteries can induce noticeable differences in the electrochemical storage mechanisms of electrode materials. Many material parameters, such as particle size, morphology, and the presence of defects, are known to further affect the storage mechanism. Here, we report an investigation of how the introduction of titanium vacancies into anatase TiO2 affects the sodium storage mechanism. From pair distribution function analysis, we observe that sodium ions are inserted into titanium vacancies at the early stage of the di…
Dendrite free electrodeposition of lithium metal is necessary for the adoption of high energy density rechargeable lithium metal batteries. Here, we demonstrate a new mechanism of using a liquid crystalline electrolyte to suppress dendrite growth with a lithium metal anode. A nematic liquid crystalline electrolyte modifies the kinetics of electrodeposition by introducing additional overpotential due to its bulk distortion and anchoring free energy. By extending the phase-field model, we simulate the morphological evolution of the metal anode and explore the role of bulk distortion and anchorin…
The widely used Doyler-Fuller-Newman (DFN) model for lithium-ion batteries is too computationally expensive for certain applications, which has motivated the appearance of a plethora of simpler models. These models are usually posed in an ad hoc manner, leading to inconsistencies with the DFN model and to multiple formulations of the same model, with the Single Particle Model (SPM) being a very good example of the latter. In this work, we discuss the concept of SPM-type models showing that, despite the multiple formulations found in the literature, these models always follow the same structure…
The solid-state diffusion coefficient of the electrode active material is one of the key parameters in lithium-ion battery modelling. Conventionally, this diffusion coefficient is estimated through the galvanostatic intermittent titration technique (GITT). In this work, the validity of GITT and a faster alternative technique, intermittent current interruption (ICI), are investigated regarding their effectiveness through a black-box testing approach. A Doyle-Fuller-Newman model with parameters for a LiNi$_{0.8}$Mn$_{0.1}$Co$_{0.1}$O$_2$ electrode is used as a fairly faithful representation as a…
