Anode For Na-ion Batteries Research Articles

Insight into the slope-plateau capacity behaviour of polymer-derived silicon oxycarbide anodes in Na-ion batteries

Silicon oxycarbide-based amorphous ceramic material was prepared by crosslinking and step-wise pyrolysis of polysiloxane-based Polyramic resin at temperatures up to 1200 °C as a matrix for anode in Na-ion batteries (NIBs). The synthesized powder was milled under low and high energy ball milling (LEM, HEM) conditions to investigate the effect of powder characteristics on the electrochemical properties of anodes in NIBs. The XPS and EDX analyses showed that the chemical compositions of anodes prepared from LEM and HEM SiOC were similar. However, the SiOC anodes prepared from finer grain sized HEM SiOC powders exhibited better performance like lower charge transfer resistance and faster Na+ diffusion coefficient. The slope capacity and thereby the total specific capacity was enhanced in HEM-SiOC anode. Therefore, the refinement of the particle size and increased surface area are vital for producing high-energy density SiOC anodes for NIBs.

Composition Analysis of the Solid Electrolyte Interface of NaK Anodes in Na-Ion Batteries.

Sodium-ion batteries have emerged as a promising alternative to Li-ion batteries due to the abundance of sodium. However, anodes in Na-ion batteries face challenges such as dendrite formation and an unstable solid electrolyte interface layer. To address these challenges, NaK liquid metal alloy anodes have been proposed as an alternative because they do not form dendrites. In our study, we demonstrate that the NaK alloy anode interacts with the commonly used ethylene carbonate and dimethyl carbonate electrolyte, leading to a continuously growing unstable SEI layer, evidenced by cycling failures under 100 cycles and an increasing charge transfer resistance in electrochemical impedance spectroscopy studies. In situ surface-enhanced Raman spectroscopy and X-ray photoelectron spectroscopy reveal that over the course of cycling the surface of the NaK anode becomes increasingly sodium-rich. After 30 cycles, XPS analysis detects only trace amounts of potassium on the NaK anode surface. When the electrolyte is analyzed postcycling using inductively coupled plasma optical emission spectroscopy, there is a noticeable increase in potassium levels, suggesting that potassium metal dissolves into the electrolyte. The introduction of a 10 wt % fluoroethylene carbonate additive can mitigate this problem to some extent, enabling an enhanced cycling performance of up to 800 cycles at 1C. Nevertheless, the dissolution of K metal is still evident in the XPS results, albeit to a lesser degree. These discoveries provide valuable insights for designing a more robust SEI layer for the NaK anode.

Tuning the electrochemical performance of Cr2B2 MBene anodes for Li and Na-ion batteries through F and Cl-functionalization: A DFT and AIMD study

In an era in which sustainable energy sources and electric vehicles are prevalent, the development of efficient anode materials is paramount to address the pressing demand for improved energy storage technologies. After the graphene revolution, many other 2D materials such as graphene, MXene (atomically thin layer of Transition Metal Carbide/Nitride/Carbonitride), TMDC (Transition Metal Dichalcogenide), and MBene (atomically thin layer of Transition Metal Borides) have emerged as potential high-performance anode materials. A recent study demonstrated the possibility of synthesizing chromium-based MBenes for the first time, and the electrochemical performance of Cr2B2 as a potential anode material has also been studied theoretically. Inspired by this, the current study utilized density functional theory and ab initio molecular dynamics simulations to probe the role of Cl and F-functionalization of Cr2B2 MBenes as anode materials for rechargeable lithium-ion batteries (LIB) and sodium-ion batteries (NIB). The electronic structure, adsorption, diffusion, and storage capacity of Li (Lithium) and Na (Sodium) were systematically investigated. This study revealed that Cr2B2F2 and Cr2B2Cl2 exhibit excellent conductivity due to their intrinsic metallic properties. In addition, they have low diffusion energy barriers for Li and Na ions (0.13/0.14 and 0.20/0.20 eV for Cr2B2F2 and Cr2B2Cl2, respectively) facilitating rapid charge/discharge rates. The calculations further unveiled a notable Li-ion storage capacity of 818 mAh g-1 for 2D Cr2B2Cl2, accompanied by a moderate open-circuit voltage (OCV) range of 0.38 V to 0.98 V, illustrating its potential as a superior anodic material for LIBs. Similarly, Cr2B2F2 demonstrated a substantial Na-ion storage capacity of 655 mAh g-1, coupled with a reasonably ranged average OCV of 0.20 V to 0.71 V, positioning it as a compelling candidate for NIBs. In all, this investigation has identified two superior electrode materials for alkali-ion batteries, which can spark additional interest in exploring MBene as a promising candidate for advancing next-generation anode materials.

Stable and fast Na-ion storage of recovered carbon from the spent carbon cathode of aluminum electrolysis

The recovered carbon from aluminum electrolysis is used as the anode for Na-ion battery. It discharges specific capacity of 134 mA h g−1 at current density of 5000 mA g−1. It gives ∼100% capacity retention after cycled 2000 times under 1000 mA g−1.

Understanding the fast kinetics and mechanism of sodium storage in antimony using ab initio grand canonical Monte Carlo simulation and operando X-ray scattering

Using ai-GCMC simulations, operando WAXS, and kinetics analysis, we found that the high-rate performance of Sb as an alloy anode in Na-ion batteries is due to the presence of an amorphous intermediate phase formed during sodiation and desodiation.

First principles study of a triazine-based covalent organic framework as a high-capacity anode material for Na/K-ion batteries.

The rational design of high-performance anode materials is crucial for the development of rechargeable Na-ion batteries (NIBs) and K-ion batteries (KIBs). In this study, based on density functional theory (DFT) calculations, we have systematically investigated the possibility of a bilayer triazine-based covalent organic framework (bilayer TCOF) as an anode for NIBs and KIBs. The calculation of the electronic band structure shows that the bilayer TCOF is a direct band gap semiconductor with a band gap of 2.01 eV. After the adsorption of Na/K at the most favorable sites, the bilayer TCOF transitions from a semiconductor to a metal state, guaranteeing good electronic conductivity. The low diffusion barriers of the bilayer TCOF are 0.45 and 0.26 eV, respectively, indicating a fast diffusion rate of Na/K ions. In addition, the bilayer TCOF has a theoretical storage capacity of up to 628 mA h g-1. Finally, it is found that the average voltage of the bilayer TCOF for NIBs and KIBs is 0.53 and 0.48 V, respectively. Based on these results, we can conclude that the bilayer TCOF may be a suitable anode material for NIBs and KIBs.

Chromium tetraphosphide (CrP4) as a high-performance anode for Li ion and Na ion batteries

The CrP4 nanoparticles and CrP4/C nanocomposite were synthesized via high-energy mechanical milling and applied as anodes for LIBs and SIBs.

Identifying the charge storage mechanism in polyimide anodes for Na-ion aqueous batteries by impedance spectroscopy

This work proposes a new electrochemical impedance model for the redox mechanism of polyimide anodes in aqueous Na-ion batteries. It provides key insights into the discrepancy between experimental and theoretical specific capacities.

Coal-derived porous carbon anodes for Na-ion batteries

Coal-derived porous carbon anodes for Na-ion batteries

Electrochemical characterization of γ-Fe2O3 and reduced graphene oxide composite as a sustainable anode material for Na-ion batteries

In this paper we report the synthesis and characterization of a γ-Fe2O3/reduced graphene oxide composite anode for Na-ion batteries. The nanocomposite anode is synthesized by a facile and green method....

Evaluation of the performance of N-doped graphene, synthesized by solvothermal method, as anode for Na-ion and Li-ion batteries

Evaluation of the performance of N-doped graphene, synthesized by solvothermal method, as anode for Na-ion and Li-ion batteries

Probing the Mo-Redox in Alluaudite Battery Materials

Alluaudites are essentially naturally occurring mixed metal (Mn and Fe) phosphate-based minerals [1] consisting of an open framework structure to support fast alkali migration. The general formula for alluaudite can be expressed by A(1)A(2)M(1)M(2)2(XO4)3 where A and M sites are alkali ion and transition metals respectively and X can be S, P, As, Mo, W, V and so on [2]. The presence of polyanionic moieties (XO4) assures structural stability and high-voltage operation arising from the inductive effect [3]. Till date, a variety of phosphate and sulfate-based alluaudites have been reported as cathodes for Li-ion and Na-ion batteries [4,5].In 2017, the first molybdate-based alluaudite material, Na2.67Mn1.67(MoO4)3, was reported as a 3.45 V Mn-based cathode [6]. Inspired by this work, we have explored other 3d (Co, Ni) based molybdate alluaudite homologues as potential compounds with desirable electrochemical and electrocatalytic activities. Solution combustion synthesis was employed to prepare phase pure Na36Co1.32(MoO4)3 by restricting the annealing duration to one minute as compared to the reported solid-state route warranting prolonged (100 h) annealing. It was found to act as a high-voltage cathode (4 V vs Na/Na+ and 4.1 V vs Li/Li+) involving Co3+/Co2+ redox center [7] while cycling between 3.0 V to 4.3 V. The above-mentioned alluaudite consists of Mo species, which can be redox-active at lower voltages. When cycled in a low-voltage window (0.01 V to 3.0 V), this material was found to act as an anode for both Li-ion and Na-ion batteries. High capacity (ca 400-500 mAh/g) was obtained with a central potential ~0.6 V involving conversion and (de)insertion reaction mechanism. The Ni-analogue, Na4Ni0.8(MoO4)2 alluaudite, was studied as an anode material in both Li-ion and Na-ion batteries involving conversion and (de)intercalation redox mechanisms like the Co- analogue. The underlying redox mechanism will be described for both cases involving post-mortem diffraction, electron microscopy, and spectroscopic tools as well as with the help of the density functional theory (DFT) approach. Finally, alluaudite Na4Cu(MoO4)3 was prepared by soft chemistry route, which was found to work as an anode material in the voltage window of 0.01 V to 3.0 V. The phase transformation and underlying redox mechanism will be elucidated.

Interlaced Micro-Fibrous Hard Carbon As Superior Anode for Na-Ion Battery: Insights into the Sodium Storage Mechanism and Solid Electrolyte Interface

Hard carbon has been proved to be a promising negative electrode material for sodium-ion battery (SIBs) application. In this study, we have synthesized carbonaceous anode material by pyrolysis of tissue paper waste at different temperatures ranging from 800° to 1400°C. The tissue paper pyrolyzed at 1400°C has shown highest desodiation capacity of 350 mAhg-1 at 20 mAg-1 with stable cyclic performance and 70% capacity retention after 400 cycles at 200 mAg-1. The morphology, structure and surface chemistry of the cycled hard carbon electrodes were examined by ex-situ FE-SEM, XRD, Raman and XPS. The characterization results obtained reveal the detailed insights of the solid electrolyte interface and sodium storage mechanism of the hard carbon. The parameters of diffusion kinetics were evaluated by Electrochemical Impedance Spectroscopy (EIS) and CV analysis at different sweep rates. The results obtained in the study establish tissue paper waste as a promising precursor material to synthesize carbonaceous anode for SIBs by a simple one-step pyrolysis process.

(Invited) Insights into Processes at the Electrode/Electrolyte Interface of Battery Electrodes Via Scanning (Electrochemical) Probe Microscopy

Scanning (electrochemical) probe microscopy (SEPM) techniques such as atomic force microscopy (AFM), scanning electrochemical microscopy (SECM), nano-pipette derived scanning probe methods like scanning electrochemical cell microscopy (SECCM) and hybrid methods have recently been used to study interfacial processes occurring at solid/electrolyte interfaces of battery electrodes [1]. So far, mainly Lithium-ion battery (LIB) electrodes have been studied, such as the solid-electrolyte interphase formation at graphite anodes [2,3]. Next generation battery chemistries, using earth abundant elements like sodium (Na), potassium (K), aluminum (Al) improving sustainability still suffer from insufficient knowledge of processes occurring during cycling at the electrode/electrolyte interface such as interphase formation, as gained insights from Li batteries cannot simply be transferred to post-Li chemistries.In this contribution, an overview of the potential of SEPM techniques to gain insight in interfacial process of post-Li battery chemistries will be given, focusing mainly on the SEI formation on hard carbon composite anodes for Na-ion batteries (SIBs) [4]. The influence of the electrolyte composition along with the effects of additives on the SEI formation and the nanomechanical properties of the electrode will be presented. In addition, given the abundance of Al and the high theoretical volumetric capacity, makes Al a highly attractive battery chemistry [5]. Despite these advantages, there are several challenges like the Al2O3 passivating layer and the mostly used acidic ionic liquid (IL)-based electrolyte AlCl3/1-ethyl-3-methylimidazolium chloride [EMIm]Cl that leads to corrosion, which determines the plating and stripping efficiency and therefore the overall performance. First correlative SECCM/EDX/EBSD studies on Al anodes will be presented. Acknowledgement This work contributes to the research performed at CELEST (Center for Electrochemical Energy Storage Ulm - Karlsruhe) and was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy – EXC 2154 – Project number 390874152 (POLiS Cluster of Excellence).

Facile synthesis of Cu7.2S4/RGO composites for an ultrastable and high-rate sodium storage anode

Metal sulfides with high capacity, morphology-controlled, and facile synthesis are considered as potential anodes for Na-ion batteries. However, the conductivity and structural stability of electrode materials are still hampered by its inherent low conductivity and obvious volume changes during cycling. Herein, Cu7.2S4 nanoparticles anchored on reduced graphene oxide (Cu7.2S4/RGO) are successfully prepared by solvothermal and thermal processes. The product, Cu7.2S4/RGO-10, not only features optimized the amount of RGO, but also delivers a large reversible capacity (314.4 mAh g−1 at 2 A g−1), good cycling stability (with a capacity fading of 0.11% per cycle from 2nd to 400th) and excellent rate capability (209 mAh g−1 at a high current density of 20 A g−1), making it the promising anode material for SIBs. Kinetics analysis clarifies that the high ion diffusion coefficient and the pseudo-capacitance contribution are important reasons for the superior performance. As expected, sodium-ion full cells (Cu7.2S4/RGO//Na3V2(PO4)3) also show good cycling stability.

Cobalt Oxide 2D Nanosheets Formed at a Polarized Liquid|Liquid Interface toward High-Performance Li-Ion and Na-Ion Battery Anodes.

Cobalt oxide (Co3O4)-based nanostructures have the potential as low-cost materials for lithium-ion (Li-ion) and sodium-ion (Na-ion) battery anodes with a theoretical capacity of 890 mAh/g. Here, we demonstrate a novel method for the production of Co3O4 nanoplatelets. This involves the growth of flower-like cobalt oxyhydroxide (CoOOH) nanostructures at a polarized liquid|liquid interface, followed by conversion to flower-like Co3O4 via calcination. Finally, sonication is used to break up the flower-like Co3O4 nanostructures into two-dimensional (2D) nanoplatelets with lateral sizes of 20-100 nm. Nanoplatelets of Co3O4 can be easily mixed with carbon nanotubes to create nanocomposite anodes, which can be used for Li-ion and Na-ion battery anodes without any additional binder or conductive additive. The resultant electrodes display impressive low-rate capacities (at 125 mA/g) of 1108 and 1083 mAh/g, for Li-ion and Na-ion anodes, respectively, and stable cycling ability over >200 cycles. Detailed quantitative rate analysis clearly shows that Li-ion-storing anodes charge roughly five times faster than Na-ion-storing anodes.

Electrochemically alternating voltage induction and in-situ preparation of tin-based multiphase structures anode for sodium-ion batteries

Tin-based materials possess a high-capacity as a potential anode for Na-ion batteries (SIBs), but the inferior electric conductivity and sluggish reaction kinetics limit their further development. In this paper, we have successfully constructed multiphase structure SnO2/SnS/SnS2 by combining the electrochemical induction and in-situ hydrothermal method to effectively alleviate these problems. The continuous addition of sulfur source (thioacetamide, TAA) results in the formation of a transition from pure product (SnO2) to double structure (SnO2/SnS), and finally multiphase structure (SnO2/SnS/SnS2). Compared to single or bimetal chalcogenides, the tri-metal chalcogenides have strengthened synergistic effects between diverse components. Additionally, the SnO2/SnS/SnS2 composites exhibit small grain size and abundant mesoporous structure, which aid to shorten the distance of ions transfer and increase surface active sites for Na-ions storage. The SnO2/SnS/SnS2 anode displays optimal diffusion coefficient (1.94 × 10−15 cm2 s−1) and cycling durability, with a recoverable specific discharge ability of 401 mA h g−1 over 100 cycles at 100 mA g−1 and a maintenance overpasses 77 %. These results indicate that the construction of multiphase structures is a prospective way to improve the reaction kinetics of Sn-based materials for SIBs.

Spatial Effect on the Performance of Carboxylate Anode Materials in Na-Ion Batteries.

Developing low-voltage carboxylate anode materials is critical for achieving low-cost, high-performance, and sustainable Na-ion batteries (NIBs). However, the structure design rationale and structure-performance correlation for organic carboxylates in NIBs remains elusive. Herein, the spatial effect on the performance of carboxylate anode materials is studied by introducing heteroatoms in the conjugation structure and manipulating the positions of carboxylate groups in the aromatic rings. Planar and twisted organic carboxylates are designed and synthesized to gain insight into the impact of geometric structures to the electrochemical performance of carboxylate anodes in NIBs. Among the carboxylates, disodium 2,2'-bipyridine-5,5'-dicarboxylate (2255-Na) with a planar structure outperforms the others in terms of highest specific capacity (210 mAh g-1), longest cycle life (2000 cycles), and best rate capability (up to 5 A g-1). The cyclic stability and redox mechanism of 2255-Na in NIBs are exploited by various characterization techniques. Moreover, high-temperature (up to 100°C) and all-organic batteries based on a 2255-Na anode, a polyaniline (PANI) cathode, and an ether-based electrolyte are achieved and exhibited exceptional electrochemical performance. Therefore, this work demonstrates that designing organic carboxylates with extended planar conjugation structures is an effective strategy to achieve high-performance and sustainable NIBs.

Computational verification of conductive Be2Zn monolayer as a superior anode for alkali and alkaline ion batteries

Availability of high-performance anode materials remains a great challenge for the clean energy storage systems. Here, we predict the planar hexacoordinate Be2Zn monolayer by first-principles calculations as a highly conductive metallic conductor with all-round structural stabilities. More impressively, the material delivers ultrahigh theoretical specific capacities of 1285, 1928, 1285, and 3856 mA h g−1 for Li, Na, K, and Ca atoms, respectively, with low migration barriers of 18, 7, 4, and 119 meV as well as with favorite average open-circuit voltages of 0.346, 0.366, 0.322, and 0.151 V. Its structural reversibility at the maximum loading concentrations is jointly confirmed by ab-initio molecular dynamics simulations at the upper temperature of 400 K for commercial battery operation under normal ambient environments and subsequent energy minimization calculations. Moreover, the monolayer can tolerate heavy tensile strain up to around 20% far surpassing the structural deformations at different charging stages, which convincingly guarantees its superlative cycle stability during the charging and discharging processes. Taken together, these appealing findings show that the metallic Be2Zn monolayer has great potential to be used as a universal Li, Na, K, and Ca ion battery anode.

Chiolite Na5Ti3F14: A novel sodium titanium fluoride anode for low-cost and high-performance Na-ion batteries

Fluoride-based conversion reaction electrode materials offer exceptional theoretical capacity merit for Na-ion batteries. Nevertheless, it has rarely been considered as potential anode material candidate due to (i) excessive redox potential (> 3 V) and (ii) intrinsically low reaction kinetics related to sluggish structural reorganization process. In this work, we demonstrate that chiolite Na5Ti3F14/carbon nanocomposite can deliver the outstanding electrochemical performances as the promising anode for Na-ion batteries, such as a large specific capacity of ∼425 mAh g−1 at 10 mA g−1 with a low average operating voltage, the capacity retention of ∼78 % compared to the initial capacity after 300 cycle with a high Coulombic efficiency of above 99 %, etc. We demonstrate that the chiolite Na5Ti3F14 phase can store the ∼8.33 mol Na ions through the following conversion reaction; Na5Ti3F14 + 9Na + 9e−⇔ 3Ti + 14NaF, which is clearly confirmed by various ex-situ analyses using X-ray diffraction, synchrotron-based X-ray adsorption spectroscopy, etc. We expect that this research can provide guidance toward the development of a new class of low-cost and high-performance anode materials, not only for Na-ion batteries but also for other rechargeable batteries.