Research Development on Sodium-Ion Batteries

The status of ambient temperature sodium ion batteries is reviewed in light of recent developments in anode, electrolyte and cathode materials. These devices, although early in their stage of development, are promising for large-scale grid storage applications due to the abundance and very low cost of sodium-containing precursors used to make the components. The engineering knowledge developed recently for highly successful Li ion batteries can be leveraged to ensure rapid progress in this area, although different electrode materials and electrolytes will be required for dual intercalation systems based on sodium. In particular, new anode materials need to be identified, since the graphite anode, commonly used in lithium systems, does not intercalate sodium to any appreciable extent. A wider array of choices is available for cathodes, including high performance layered transition metal oxides and polyanionic compounds. Recent developments in electrodes are encouraging, but a great deal of research is necessary, particularly in new electrolytes, and the understanding of the SEI films. The engineering modeling calculations of Na-ion battery energy density indicate that 210 Wh kg−1 in gravimetric energy is possible for Na-ion batteries compared to existing Li-ion technology if a cathode capacity of 200 mAh g−1 and a 500 mAh g−1 anode can be discovered with an average cell potential of 3.3 V.

Sodium‐Ion Batteries

The last decade witnessed significant progress in angle-resolved photoemission spectroscopy (ARPES) and its applications. Today, ARPES experiments with 2-meV energy resolution and $0.2\ifmmode^\circ\else\textdegree\fi{}$ angular resolution are a reality even for photoemission on solids. These technological advances and the improved sample quality have enabled ARPES to emerge as a leading tool in the investigation of the high-${T}_{c}$ superconductors. This paper reviews the most recent ARPES results on the cuprate superconductors and their insulating parent and sister compounds, with the purpose of providing an updated summary of the extensive literature. The low-energy excitations are discussed with emphasis on some of the most relevant issues, such as the Fermi surface and remnant Fermi surface, the superconducting gap, the pseudogap and $d$-wave-like dispersion, evidence of electronic inhomogeneity and nanoscale phase separation, the emergence of coherent quasiparticles through the superconducting transition, and many-body effects in the one-particle spectral function due to the interaction of the charge with magnetic and/or lattice degrees of freedom. Given the dynamic nature of the field, we chose to focus mainly on reviewing the experimental data, as on the experimental side a general consensus has been reached, whereas interpretations and related theoretical models can vary significantly. The first part of the paper introduces photoemission spectroscopy in the context of strongly interacting systems, along with an update on the state-of-the-art instrumentation. The second part provides an overview of the scientific issues relevant to the investigation of the low-energy electronic structure by ARPES. The rest of the paper is devoted to the experimental results from the cuprates, and the discussion is organized along conceptual lines: normal-state electronic structure, interlayer interaction, superconducting gap, coherent superconducting peak, pseudogap, electron self-energy, and collective modes. Within each topic, ARPES data from the various copper oxides are presented.

https://arxiv.org/pdf/cond-mat/0208504.pdf

Angle-resolved photoemission studies of the cuprate superconductors

Energy production and storage technologies have attracted a great deal of attention for day-to-day applications. In recent decades, advances in lithium-ion battery (LIB) technology have improved living conditions around the globe. LIBs are used in most mobile electronic devices as well as in zero-emission electronic vehicles. However, there are increasing concerns regarding load leveling of renewable energy sources and the smart grid as well as the sustainability of lithium sources due to their limited availability and consequent expected price increase. Therefore, whether LIBs alone can satisfy the rising demand for small- and/or mid-to-large-format energy storage applications remains unclear. To mitigate these issues, recent research has focused on alternative energy storage systems. Sodium-ion batteries (SIBs) are considered as the best candidate power sources because sodium is widely available and exhibits similar chemistry to that of LIBs; therefore, SIBs are promising next-generation alternatives. Recently, sodiated layer transition metal oxides, phosphates and organic compounds have been introduced as cathode materials for SIBs. Simultaneously, recent developments have been facilitated by the use of select carbonaceous materials, transition metal oxides (or sulfides), and intermetallic and organic compounds as anodes for SIBs. Apart from electrode materials, suitable electrolytes, additives, and binders are equally important for the development of practical SIBs. Despite developments in electrode materials and other components, there remain several challenges, including cell design and electrode balancing, in the application of sodium ion cells. In this article, we summarize and discuss current research on materials and propose future directions for SIBs. This will provide important insights into scientific and practical issues in the development of SIBs.

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Sodium-ion batteries: present and future

Lithium (Li)-ion batteries (LIB) have governed the current worldwide rechargeable battery market due to their outstanding energy and power capability. In particular, the LIB's role in enabling electric vehicles (EVs) has been highlighted to replace the current oil-driven vehicles in order to reduce the usage of oil resources and generation of CO2 gases. Unlike Li, sodium is one of the more abundant elements on Earth and exhibits similar chemical properties to Li, indicating that Na chemistry could be applied to a similar battery system. In the 1970s-80s, both Na-ion and Li-ion electrodes were investigated, but the higher energy density of Li-ion cells made them more applicable to small, portable electronic devices, and research efforts for rechargeable batteries have been mainly concentrated on LIB since then. Recently, research interest in Na-ion batteries (NIB) has been resurrected, driven by new applications with requirements different from those in portable electronics, and to address the concern on Li abundance. In this article, both negative and positive electrode materials in NIB are briefly reviewed. While the voltage is generally lower and the volume change upon Na removal or insertion is larger for Na-intercalation electrodes, compared to their Li equivalents, the power capability can vary depending on the crystal structures. It is concluded that cost-effective NIB can partially replace LIB, but requires further investigation and improvement.

/pdf/electrode-materials-for-rechargeable-sodium-ion-batteries-1cf2yiiw7z.pdf

Electrode Materials for Rechargeable Sodium-Ion Batteries: Potential Alternatives to Current Lithium-Ion Batteries

Crystals of the three Bi-based cuprates of general formula ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{Ca}}_{n\ensuremath{-}1}{\mathrm{Cu}}_{n}{\mathrm{O}}_{y}$ with $n=1,2, \mathrm{and} 3$ have been isolated and their structural and physical properties investigated. The structures are similar, differing only in the number of Cu${\mathrm{O}}_{2}$-Ca-Cu${\mathrm{O}}_{2}$ slabs packed along the $c$ axis. The insertion of one and two slabs increases $c$ from 24.6 to 30.6 and 37.1 \AA{}. Transmission electron microscopy shows there are stacking faults within the crystals in agreement with our x-ray data and its analysis. Resistivity, ac susceptibility, and dc magnetization measurements demonstrate superconductivity in the $n=1,2, \mathrm{and} 3$ phases at 10, 85, and 110 K, respectively. The observed transition temperatures and the stacking fault densities are dependent upon sample processing, in particular, the annealing temperatures and cooling rates. The transition temperature is, within the accuracy of our chemical titration, independent of the average copper valency that was determined to be 2.15 \ifmmode\pm\else\textpm\fi{} 0.03 for each of the three compounds.

/pdf/preparation-structure-and-properties-of-the-superconducting-ty7xj6g4jt.pdf

Preparation, structure, and properties of the superconducting compound series Bi 2 Sr 2 Ca n-1 Cu n O y with n=1, 2, and 3

The compound ${\mathrm{Bi}}_{10}$${\mathrm{Sr}}_{15}$${\mathrm{Fe}}_{10}$${\mathrm{O}}_{46}$ is shown to be isostructural with the 80-K superconductor ${\mathrm{Bi}}_{2}$${\mathrm{Sr}}_{2}$${\mathrm{Ca}}_{2}$${\mathrm{O}}_{8.21}$. The incommensurate modulation of the Cu compound is commensurate in the crystal of the Fe compound that was selected. The modulation is caused by the insertion of extra oxygen atoms in the Bi layers and results in corrugated slabs. The structure of the Bi-O layers can be described as roughly 70% of rocksalt type and 30% of oxygen-deficient perovskite type. The results explain the excess oxygen in the superconductor, the mechanism causing the corrugation, and the inelastic bending property displayed by single crystals. They also reconcile apparently discrepant results about the oxygen distribution in the bismuth layers.

/pdf/origin-of-the-incommensurate-modulation-of-the-80-k-31hlkt2lfz.pdf

Origin of the incommensurate modulation of the 80-K superconductor Bi 2 Sr 2 CaCu 2 O 8.21 derived from isostructural commensurate Bi 10 Sr 15 Fe 10 O 46

The ${\mathrm{Bi}}_{4}$${\mathrm{Sr}}_{4}$${\mathrm{Ca}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{R}}_{\mathit{x}}$${\mathrm{Cu}}_{4}$${\mathrm{BO}}_{\mathit{y}}$ materials (R is a rare-earth element) were studied to determine their structural and physical properties. For most of the rare-earth elements, a complete solid solution exists up to x=2. Below x=0.5,${T}_{c}$ is not affected and for each added rare-earth element we find that about 0.5 oxygen atom is added to the structure. However, the structural modulation observed along the b axis for the undoped material persists and remains of the same amplitude for the rare-earth-doped samples. When more than one R(x\ensuremath{\ge}1) is substituted, ${T}_{c}$ is depressed and the compound becomes semiconducting beyond x=1.5. The depression in the ${T}_{c}$ from 85 K (x=0) to less than 4.2 K (x=1.5) correlates to a decrease in the formal valence of copper and is independent whether the rare-earth element is magnetic or nonmagnetic. No evidence for magnetic ordering over the range of temperature 1.7--400 K has been observed in all the substituted compounds. The substitution for Cu by 3d metals or for Sr by rare-earth elements fails for the 85-K Bi phase but succeeds for the 10-K Bi phase. Consequently, the following series ${\mathrm{Bi}}_{2}$${\mathrm{Sr}}_{2}$${\mathrm{Cu}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{M}}_{\mathrm{x}}$${\mathrm{O}}_{\mathrm{y}}$ (M=Fe, Co) and ${\mathrm{Bi}}_{2}$${\mathrm{RCaCuO}}_{\mathrm{y}}$ (R=La, Pr, Nd, Sm) were made for study. These substitutions result in an uptake of oxygen (0.5 for each substituted element). But the materials become semiconducting even though the formal valence of Cu remains greater than 2. An antiferromagnetic transition at 140 K has been found for the Co sample for which Co is found to be in the +3 state.

/pdf/bismuth-cuprate-high-tc-superconductors-using-cationic-26mfftwlfz.pdf

Bismuth cuprate high-Tc superconductors using cationic substitution.

We have fabricated epitaxial ferroelectric PbZr0.2Ti0.8O3/YBa2Cu3O7−x heterostructures on single crystalline [001] LaAlO3. Only the (00l) peaks of the PbZr0.2Ti0.8O3 (PZT) film are observed, indicating that the epitaxial, c‐axis oriented YBCO film is a good structural template for the heteroepitaxial growth of PZT films, in addition to being a metallic bottom electrode. A saturation polarization and remanence as high as 38 and 26.5 μC/cm2 (at 7.5 V, 0.5 kHz), respectively, have been achieved. The coercive field is about 100 kV/cm.

Ferroelectric PbZr0.2Ti0.8O3 thin films on epitaxial Y‐Ba‐Cu‐O

Single crystals of the n-type Nd-Ce-Cu-O superconducting materials have been grown via a flux technique, and their structural and physical properties characterized. Optimum crystal growth conditions were arrived at from a survey of various compositions and temperatures. We determine that the charge composition (50 mol % ${\mathrm{Nd}}_{2}$${\mathrm{O}}_{3}$--${\mathrm{CeO}}_{2}$, 50 mol % CuO) held at a temperature of 1300 \ifmmode^\circ\else\textdegree\fi{}C and followed by a slow cooling to 1000 \ifmmode^\circ\else\textdegree\fi{}C produces plateletlike crystals of the n-type phase ${\mathrm{Nd}}_{2\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Ce}}_{\mathrm{x}}$${\mathrm{CuO}}_{4}$, which, after being annealed at 900 \ifmmode^\circ\else\textdegree\fi{}C in nitrogen, become superconducting. The limit of the Ce solubility is x=0.18, and only crystals having a Ce content between 0.14 and 0.17 were found to superconductors, with the maximum ${T}_{c}$ occurring at x=0.14. The oxygen uptake and loss in the Nd material is similar to that measured on ${\mathrm{La}}_{2}$${\mathrm{CuO}}_{4}$ but occurs at higher temperatures (750 \ifmmode^\circ\else\textdegree\fi{}C instead of 500 \ifmmode^\circ\else\textdegree\fi{}C). The large Meissner fraction indicates bulk superconductivity. However, due to a complex microstructure or compositional (e.g., oxygen) inhomogeneities in the crystal, zero resistance is difficult to achieve. The resistivity temperature dependence above ${T}_{c}$ is metalliclike, and linear above 150 K, in contrast to bulk ceramics. Finally, no evidence for magnetic ordering over the temperature range 4--350 K was observed for the superconducting Ce-doped ${\mathrm{Nd}}_{2}$${\mathrm{CuO}}_{4}$ phase, whereas signs of magnetic ordering were found at 340 K for the undoped material.

/pdf/growth-structural-and-physical-properties-of-superconducting-4rf9dr53a7.pdf

J. M. Tarascon

Papers

Preparation, structure, and properties of the superconducting compound series Bi 2 Sr 2 Ca n-1 Cu n O y with n=1, 2, and 3

Origin of the incommensurate modulation of the 80-K superconductor Bi 2 Sr 2 CaCu 2 O 8.21 derived from isostructural commensurate Bi 10 Sr 15 Fe 10 O 46

Bismuth cuprate high-Tc superconductors using cationic substitution.

Ferroelectric PbZr0.2Ti0.8O3 thin films on epitaxial Y‐Ba‐Cu‐O

Growth, structural, and physical properties of superconducting Nd2-xCexCuO4 crystals.