The relationship between the redox activity and electrochemical stability of solid electrolytes for solid-state batteries
Tammo Schwietert, Violetta Arszelewska, Chuang Yu, Chao Wang, Alexandros Vasileiadis, Niek J. J. de Klerk, Jart Hageman, Thomas Hupfer, Ingo Kerkamm, Yaolin Xu,… 展开作者
Tammo Schwietert, Violetta Arszelewska, Chuang Yu, Chao Wang, Alexandros Vasileiadis, Niek J. J. de Klerk, Jart Hageman, Thomas Hupfer, Ingo Kerkamm, Yaolin Xu, Eveline van der Maas, Erik M. Kelder, Swapna Ganapathy, Marnix Wagemaker
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 is that the electrochemical stability window of the solid electrolyte is significantly larger than predicted for direct decomposition, rationalizing the observed stability window. The observed argyrodite metastable (de)lithiated solid electrolyte phases contribute to the (ir)reversible cycling capacity of all-solid-state batteries, in addition to the contribution of the decomposition products, comprehensively explaining solid electrolyte redox activity. The fundamental nature of the proposed mechanism suggests this is a key aspect for solid electrolytes in general, guiding interface and material design for all-solid-state batteries.
Rechargeable redox flow batteries with serpentine flow field designs have been demonstrated to deliver higher current density and power density in medium and large-scale stationary energy storage applications. Nevertheless, the fundamental mechanisms involved with improved current density in flow batteries with flow field designs have not been understood. Here we report a maximum current density concept associated with stoichiometric availability of electrolyte reactant flow penetration through the porous electrode that can be achieved in a flow battery system with a "zero-gap"serpentine flow …
Redox flow batteries (RFBs) have gained popularity as large-scale energy storage systems for wind and solar powered grids. Modern RFB systems are based on highly corrosive and/or flammable electrolytes. Organic redox active species for RFBs are gaining commercial traction, but there is a trade-off in choosing aqueous or non-aqueous electrolytes in terms of rate capabilities, energy density, safety and cost. While modification of organic redox molecules to mitigate these issues is prevalent in the literature, the search for novel electrolyte systems is scarce. Here we present microemulsion-base…
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 reversibility and cyclability of anionic redox in battery electrodes hold the key to its practical employments. Here, through mapping of resonant inelastic X-ray scattering (mRIXS), we have independently quantified the evolving redox states of both cations and anions in Na2/3Mg1/3Mn2/3O2. The bulk-Mn redox emerges from initial discharge and is quantified by inverse-partial fluorescence yield (iPFY) from Mn-L mRIXS. Bulk and surface Mn activities likely lead to the voltage fade. O-K super-partial fluorescence yield (sPFY) analysis of mRIXS shows 79% lattice oxygen-redox reversibility during…
Electrochemical devices often consist of multicomponent electrolyte solutions. Two processes influence the overall dynamics of these devices: the formation of electrical double layers and chemical conversion due to redox reactions. However, due to the presence of multiple length and time scales, it is challenging to simulate both processes directly from the Poisson-Nernst-Planck equations. Therefore, common modeling approaches ignore one of the processes, assume the two are independent, or extrapolate the results from reaction-free systems. To overcome these limitations, we formulate and deriv…
Realizing reversible reduction-oxidation (Redox) reactions of lattice oxygen in batteries is a promising way to improve the energy and power density. However, conventional oxygen absorption spectroscopy fails to distinguish the critical oxygen chemistry in oxide-based battery electrodes. Therefore, high-efficiency full-range mapping of resonant inelastic X-ray scattering (mRIXS) has been developed as a reliable probe of oxygen redox reactions. Here, based on mRIXS results collected from a series of Li1.17Ni0.21Co0.08Mn0.54O2 electrodes at different electrochemical states and its comparison wit…
Redox flow batteries (RFBs) are potential solutions for grid-scale energy storage, and deeper understanding of the effect of flow rate on RFB performance is needed to develop efficient, low-cost designs. In this study we highlight the importance of modeling tanks, which can limit the charge/discharge capacity of redox-active polymer (RAP) based RFBs. The losses due to tank mixing dominate over the polarization-induced capacity losses that arise due to resistive processes in the reactor. A porous electrode model is used to separate these effects by predicting the time variation of active specie…
Ferrocene, since its discovery in 1951, has been extensively exploited as a redox probe in a variety of processes ranging from solution chemistry, medicinal chemistry, supramolecular chemistry, surface chemistry to solid-state molecular electronic and spintronic circuit elements to unravel electrochemical charge-transfer dynamics. Ferrocene represents an extremely chemically and thermally stable, and highly reproducible redox probe that undergoes reversible one-electron oxidation and reduction occurring at the interfaces of electrode/ferrocene solution in response to applied anodic and cathodi…
Micro emulsions (MEs) offer an exceptionally broad spectrum of applications covering sensing, electrosynthesis, supercapacitors and redox-flow batteries. Herein, we develop the theory for a sophisticated electrochemical characterizion of MEs with a spatially and time-invariant anisotropy in the diffusion domain by means of cyclic voltammerty (CV). By introducing spatially dependent diffusion coefficients into Ficks' first law, we derive a modified diffusion equation to simulate any inherent anisotropy of the ME under investigation. Moreover, by formulating an extended second-order homogeneous …
Micro and nanostructured electrodes form an integral part of a wide variety of electrochemical systems for biomolecule detection, batteries, solar cells, scanning electrochemical microscopy, etc. Given the complexity of the electrode structures, the Butler-Volmer formalism of redox reactions, and the diffusion transport of redox species, it is hardly surprising that only a few problems are amenable to closed form, compact analytical solutions. While numerical solutions are widely used, it is often difficult to integrate the insights gained to the design and optimization of electrochemical syst…
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…
As power generated from renewables becomes more readily available, the need for power-efficient energy storage devices, such as redox flow batteries, becomes critical for successful integration of renewables into the electrical grid. An important component in a redox flow battery is the planar flow field, which is usually composed of two-dimensional channels etched into a backing plate. As reactant-laden electrolyte flows into the flow battery, the channels in the flow field distribute the fluid throughout the reactive porous electrode. We utilize topology optimization to design flow fields wi…
The parasitic reactions associated with reduced oxygen species and the difficulty in achieving the high theoretical capacity have been major issues plaguing development of practical non-aqueous Li-O2 batteries. We hereby address the above issues by exploring the synergistic effect of 2,5-di-tert-butyl-1,4- benzoquinone and H2O on the oxygen chemistry in a non-aqueous Li-O2 battery. Water stabilizes the quinone monoanion and dianion, shifting the reduction potentials of the quinone and monoanion to more positive values (vs. Li+). When water and the quinone are used together in a (largely) non-a…
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…
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…
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…
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…
Biredox ionic liquids are a new class of functionalized electrolytes that may play an important role in future capacitive energy storage devices. By allowing additional storage of electrons inside the liquids, they can improve device performance significantly. However current devices employ nanoporous carbons in which the diffusion of the liquid and the adsorption of the ions could be affected by the occurrence of electron-transfer reactions. It is therefore necessary to understand better the thermodynamics and the kinetics of such reactions in biredox ionic liquids. Here we perform ab initio …
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…
Cobalt-porphyrin catalyzed reductive decomposition of CO2 to CO is investigated based on Koper's water facilitated CO2 reduction mechanism using a simple but accurate protocol based on thermodynamics. In our protocol, accurate predictions of standard redox potentials and free energy differences are achieved by combining strengths of both density functional theory and experimental observations. With the proposed protocol, we found that the proton transfer from H2O takes place at -0.80 V vs. RHE at pH=3 through a concerted pathway and, as a result, the key intermediate for the CO generation, i.e…
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…
Fluoroethylene carbonate (FEC) shows promise as an electrolyte additive for improving passivating solid-electrolyte interphase (SEI) films on silicon anodes used in lithium ion batteries (LIB). We apply density functional theory (DFT), ab initio molecular dynamics (AIMD), and quantum chemistry techniques to examine excess-electron-induced FEC molecular decomposition mechanisms that lead to FEC-modified SEI. We consider one- and two-electron reactions using cluster models and explicit interfaces between liquid electrolyte and model Li(x)Si(y) surfaces, respectively. FEC is found to exhibit more…
Batteries are pivotal components in overcoming some of today's greatest technological challenges. Yet to date there is no self-consistent atomistic description of a complete battery. We take first steps toward modeling of a battery as a whole microscopically. Our focus lies on phenomena occurring at the electrode-electrolyte interface which are not easily studied with other methods. We use the redox split-charge equilibration (redoxSQE) method that assigns a discrete ionization state to each atom. Along with exchanging partial charges across bonds, atoms can swap integer charges. With redoxSQE…
The requirements for beneficial materials restructuring into a higher performance OER electrocatalyst are still a largely open question. Here we use Erythrite (Co$_3$(AsO$_4$)$_2\cdot$8H$_2$O) as a Co-based OER electrocatalyst to evaluate its catalytic properties during in-situ restructuring into an amorphous Co-based catalyst in four different electrolytes at pH 7. Using diffraction, microscopy and spectroscopy, we observed a strong effect in the restructuring kinetics depending of the anions in the electrolyte. Only carbonate electrolyte could activate the catalyst electrode, which we relate…
The amorphous propagation of microstructures during the electrochemical charging of a battery is the main reason for the capacity decay and short circuit. The charge distribution across the micro-structure is the result of both local and global equilibrium and is non-convex problem merely due to stochastic placement of the atoms. As such, obtaining the charge equilibrium (QEq) is a critical factor, since the amount of charge determines the success rate of the bond formation for the ionic species approaching the microstructure and consequently the ultimate morphology of the electrochemical depo…
In search of the potential cathode materials for sodium-ion batteries and to understand the diffusion kinetics, we report the detailed analysis of electrochemical investigation of honeycomb structured Na$_{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$3.9~V at 1~C and high capacity retention …
Electrochemical performance and diffusion kinetics of a NASICON type Na$_{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）
Improved electrochemical performance of NASICON type Na$_{3}$V$_{2-x}$Co$_x$(PO$_{4}$)$_{3}$/C ($x=$ 0--0.15) cathode for high rate and stable sodium-ion batteries
本文研究 NASICON 型 Na$_{3}$V$_{2-x}$Co$_x$(PO$_{4}$)$_{3}$/C 正极，证明适量 Co 取代 V 位可提升高倍率容量、扩散动力学与长循环稳定性。
Recently, dinitriles (NC(CH2)nCN) and especially adiponitrile (ADN, n=4) have attracted the attention as secure electrolyte solvents due to their chemical stability, high boiling points, high flash points and low vapor pressure. The good solvating properties of ADN toward lithium salts and its high electrochemical stability (~ 6V vs. Li/Li+) make it suitable for safer Li-ions cells without performances loss. In this study, ADN is used as a single electrolyte solvent with lithium bis(trimethylsulfonyl)imide (LiTFSI). This electrolyte allows the use of aluminum collectors as almost no corrosion …
Among the 'beyond Li-ion' battery chemistries, nonaqueous Li-O$_2$ batteries have the highest theoretical specific energy and as a result have attracted significant research attention over the past decade. A critical scientific challenge facing nonaqueous Li-O$_2$ batteries is the electronically insulating nature of the primary discharge product, lithium peroxide, which passivates the battery cathode as it is formed, leading to low ultimate cell capacities. Recently, strategies to enhance solubility to circumvent this issue have been reported, but rely upon electrolyte formulations that furthe…
The world is at the cusp of a new era where pivotal importance is being attached to the development of sustainable and high-performance energy storage systems. Potassium-ion batteries are deemed not only as cheap battery candidates, but also as the penultimate high-voltage energy storage systems within the monovalent-cation chemistries. However, their performance and sustainability are undermined by the lack of suitable electrolytes for high-voltage operation particularly due to the limited availability of cathode materials. Here, the potential of ionic liquids based on potassium bis(trifluoro…
Mixed Polyanionic NaFe$_{1.6}$V$_{0.4}$(PO$_{4}$)(SO$_{4}$)$_{2}$@CNT Cathode for Sodium-ion Batteries: Electrochemical Diffusion Kinetics and Distribution of Relaxation Time Analysis at Different Temperatures
We consider basic and easily extendible transport formulations for lithium batteries consisting of an anode (Li-foil), a separator (polymer electrolyte), and a composite cathode (composed of electrolyte and intercalation particles). Our mathematical investigations show the following novel features: (i) \emph{complete and very basic description of mixed transport processes} relying on a neutral, binary symmetric electrolyte resulting in a non-standard Poisson equation for the electric potential together with interstitial diffusion approximated by classical diffusion; (ii) \emph{ upscaled and ba…
Confinement-controlled Water Engenders High Energy Density Electrochemical-double-layer Capacitance
Skolkovo Institute of Science and Technology（斯克隆沃科学技术研究所）；Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院）；École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）；Max Planck Institute for Polymer Research（马克斯·普朗克高分子研究所）
