Rechargeable Alkali-ion Batteries Research Articles

Low-Dimensional Vanadium-Based High-Voltage Cathode Materials for Promising Rechargeable Alkali-Ion Batteries.

Owing to their rich structural chemistry and unique electrochemical properties, vanadium-based materials, especially the low-dimensional ones, are showing promising applications in energy storage and conversion. In this invited review, low-dimensional vanadium-based materials (including 0D, 1D, and 2D nanostructures of vanadium-containing oxides, polyanions, and mixed-polyanions) and their emerging applications in advanced alkali-metal-ion batteries (e.g., Li-ion, Na-ion, and K-ion batteries) are systematically summarized. Future development trends, challenges, solutions, and perspectives are discussed and proposed. Mechanisms and new insights are also given for the development of advanced vanadium-based materials in high-performance energy storage and conversion.

Mixed anion chemistry as a way to tune the electrochemical properties of vanadium oxyfluoride phosphates in alkali-ion batteries

Alkali vanadium fluoride phosphates such as Tavorite LiVPO4F, Na3V2(PO4)2F3 and KTP-type KVPO4F are attractive materials for positive electrodes in rechargeable alkali-ion batteries. In such compounds, the presence of fluoride ions further increases the electrode's electrochemical potential compared to their phosphate counterparts such as Na3V2(PO4)3. Furthermore, the fluoride anions in these structures can be fully or partially substituted by oxide anions, leading to the formation of V4+=O vanadyl centres and a great number of mixed valence and mixed anion compositions. The oxygen substitution for fluorine has a considerable impact on the structural, electronic, and electrochemical properties of the resulting compounds. In this review, the similarities and peculiarities in the crystal structures, electronic structures, and electrochemical properties of the three analogous LiVPO4F–LiVPO4O, Na3V2(PO4)2F3–Na3V2(PO4)2FO2, and KVPO4F−KVPO4O material families will be compared in detail. Such a comparison is expected to provide an insightful understanding on the factors governing the structure and properties of vanadium oxyfluoride phosphates.

Composite modulated structures of electrode materials for rechargeable alkali-ion batteries

Composite modulated structures of electrode materials for rechargeable alkali-ion batteries

Pyrolyzed Organic Pigment as Efficient Surface-Dominated Alkali-Ion Storage Anodes.

Carbonaceous materials have attracted as prospective anodes for rechargeable alkali-ion batteries. In this study, C.I. Pigment Violet 19 (PV19) was utilized as a carbon precursor to fabricate the anodes for alkali-ion batteries. During thermal treatment, the generation of gases from the PV19 precursor triggered a structural rearrangement into nitrogen- and oxygen-containing porous microstructures. The anode materials fabricated from pyrolyzed PV19 at 600 °C (PV19-600) showed outstanding rate performance and stable cycling behavior (554 mAh g-1 over 900 cycles at a current density of 1.0 A g-1) in lithium-ion batteries (LIBs). In addition, PV19-600 anodes exhibited reasonable rate capability and good cycling behavior (200 mAh g-1 after 200 cycles at 0.1 A g-1) in sodium-ion batteries (SIBs). To define the enhanced electrochemical performance of PV19-600 anodes, spectroscopic analyses were employed to reveal the storage mechanism and kinetics of the alkali ions in pyrolyzed PV19 anodes. A surface-dominant process in nitrogen- and oxygen-containing porous structures was found to promote the alkali-ion storage ability of the battery.

Fe(iii)-carboxythiolate layered metal–organic frameworks with interest as active materials for rechargeable alkali-ion batteries

A series of Fe(iii)-thiolate layered MOFs was prepared. These solids present a strong absorption in the visible range, a good chemical stability and an interesting electrochemical activity.

Nitrogen-doped meso-macroporous carbon from waste asphalt as high-performance anode materials for alkali-ion batteries

Rechargeable alkali-ion (Li+, Na+, and K+) batteries with high conversion efficiency have attracted much attention for portable and sizeable energy storage. Deriving valuable battery materials from valueless waste materials is highly desirable to meet the surging demand of energy storage. However, waste-derived carbon materials often show low specific capacity and poor reversibility due to untamed physiochemical properties. In this paper, nitrogen doped meso-macroporous carbon (NMPC) materials are produced from waste asphalt with the assistance of nano-Fe2O3 template and melamine modification. The products show interconnected three-dimensional meso-macroporous structures and tunable nitrogen contents. As an anode material for Li-ion batteries, the NMPC with optimum nitrogen content delivers a reversible capacity of 602.3 mA h g−1 at 0.2 A g−1. Furthermore, it also discharges a reversible capacity of 210.8 mA h g−1 after 200 cycles and 201.5 mA h g−1 after 500 cycles for Na-ion batteries and K-ion batteries, respectively. The excellent and versatile electrochemical properties enable the concept of waste recovery and resource utilization, which can be used for the manufacture of environmentally friendly energy storage systems.

2D and Layered Ti-based Materials for Supercapacitors and Rechargeable Batteries: Synthesis, Properties, and Applications

: Titanium-based two-dimensional (2D) and layered compounds with open and stable crystal structures have attracted increasing attention for energy storage and conversion purposes, e.g., rechargeable alkali-ion batteries and hybrid capacitors, due to their superior rate capability derived from the intercalation-type or pseudocapacitive kinetics. Various strategies, including structure design, conductivity enhancement, surface modification, and electrode engineering, have been implemented to effectively overcome the intrinsic drawbacks while simultaneously maintaining their advantages as promising and competitive electrode materials for advanced energy storage and conversion. Here, we provide a comprehensive overview of the recent progress on Ti-based compound materials for highrate and low-cost electrochemical energy storage applications (mainly on rechargeable batteries and supercapacitors). The energy storage mechanisms, structure-performance relations, and performanceoptimizing strategies in these typical energy storage devices are discussed. Moreover, major challenges and perspectives for future research and industrial application are also illustrated.

Realization of high cycle life bismuth oxychloride Na-ion anode in glyme-based electrolyte

Two-dimensional bismuth oxychloride (BiOCl) is recently explored as an anode in rechargeable alkali-ion batteries because its layered structure facilitates ionic diffusion and higher specific capacities. However, its application is mainly challenged by rapid capacity decay originating from particle pulverization and unstable solid electrolyte interphase (SEI). Herein, we demonstrate the higher cycling stability of BiOCl anode in Na-ion batteries (NIBs) by simply coupling it with diglyme-based electrolyte. The BiOCl anode delivers reversible capacities greater than 295 mA h g−1 for 650 cycles at 100 mA g−1. It also displays excellent rate performances (∼278 and 267 mA h g−1 at 200 and 500 mA g−1, respectively) and higher durability under different current rates. Such stellar performance of BiOCl anode is attributed to the formation of stable SEI and maintenance of electrode integrity as revealed by the post-mortem studies. Besides, the electrochemical (de)sodiation mechanism of BiOCl anode is also clarified through in-operando X-ray diffraction (XRD) studies, which reveals the reversible formation of Bi ↔ NaBi ↔ cubic-Na3Bi phases. This report emphasizes the importance of electrolyte engineering as an excellent way to build stable SEI and achieve high-performance advanced alloy anodes for NIB application.

Spent asphalt-derived mesoporous carbon for high-performance Li/Na/K-ion storage

Along with the surging demand for rechargeable alkali-ion (Li + , Na + , or K + ) batteries, cost and availability of the battery materials become critical. In this paper, we report the use of spent asphalt, which is widely available and even poses environmental risks, to produce a high-performing universal Li/Na/K-ion host material. Taking advantage of a nano-Fe 2 O 3 template, the spent asphalt is converted into mesoporous carbon with an interconnected three-dimensional porous structure, high surface area, and numerous crystal defects. As an anode material for Li-ion batteries, the mesoporous carbon exhibits a reversible capability of 674.2 mA h g −1 at 0.2 A g −1 as well as excellent rate and cycling performance (258.7 mA h g −1 at 1.0 A g −1 after 1000 cycles) owing to the shortened diffusion path of ion and easier penetration of electrolytes. The carbon anode also delivers superior reversible capacities and cycling stability in Na-ion and K-ion batteries. With the potential to simultaneously tackle energy and environmental problems, the spent asphalt-derived mesoporous carbon is promising for large-scale applications. • Spent asphalt is used as a raw material to produce mesoporous carbon. • The product has interconnecting pores, high surface area, and crystal defects. • The product exhibits appealing electrochemical properties in Li/Na/K-ion batteries. • The study is promising for waste reclamation of spent asphalt.

Recent Progress on In Situ/Operando Characterization of Rechargeable Alkali Ion Batteries.

The specific chemical and physical evolutions of electrode materials under operating conditions should be understood to optimize their electrochemical performances. The in-situ/operando techniques including Raman spectrum, transmission electron microscope, X-ray diffraction, X-ray absorption spectrum, and magnetization are powerful tools, which can provide the real-time surficial/interfacial changes of electrodes, the transformation of crystal lattice structures, the adjustment of electronic states and even the influence of magnetic properties under operating conditions. In this Review, the advantages and limitations of these in-situ/operando techniques in investigating the inner energy storage mechanisms of various type electrode materials are analyzed. The representative research results such as the ion dependent storage mechanism, step-alloying processes and space charge storage theory are highlighted. In addition, the challenges and opportunities of in-situ/operando characterizations are proposed as well.

Anchoring SnS2 on TiC/C Backbone to Promote Sodium Ion Storage by Phosphate Ion Doping.

Tin disulfide (SnS2 ) shows promising properties toward sodium ion storage with high capacity, but its cycle life and high rate capability are still undermined as a result of poor reaction kinetics and unstable structure. In this work, phosphate ion (PO4 3- )-doped SnS2 (P-SnS2 ) nanoflake arrays on conductive TiC/C backbone are reported to form high-quality P-SnS2 @TiC/C arrays via a hydrothermal-chemical vapor deposition method. By virtue of the synergistic effect between PO4 3- doping and conductive network of TiC/C arrays, enhanced electronic conductivity and enlarged interlayer spacing are realized in the designed P-SnS2 @TiC/C arrays. Moreover, the introduced PO4 3- can result in favorable intercalation/deintercalation of Na+ and accelerate electrochemical reaction kinetics. Notably, lower bandgap and enhanced electronic conductivity owing to the introduction of PO4 3- are demonstrated by density function theory calculations and UV-visible absorption spectra. In view of these positive factors above, the P-SnS2 @TiC/C electrode delivers a high capacity of 1293.5 mAh g-1 at 0.1 A g-1 and exhibits good rate capability (476.7 mAh g-1 at 5 A g-1 ), much better than the SnS2 @TiC/C counterpart. This work may trigger new enthusiasm on construction of advanced metal sulfide electrodes for application in rechargeable alkali ion batteries.

Acetate-Based Water-in-Salt Electrolyte for Aqueous Sodium-Ion Batteries

Aqueous rechargeable alkali-ion batteries have attracted considerable interest in recent years due to reduced cost, lower environmental impact and, most importantly, and improved safety.1 Unfortunately, the narrow electrochemical stability window of water (1.23 V) limits the maximum output voltage of aqueous batteries, thus leading to intrinsically low energy density. Water-in-salt electrolytes (WiSE) constituted of, for example, highly concentrated lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) solutions, has promoted the development of aqueous LIBs.2 However, these highly concentrated electrolytes based on fluorinated salts spoil the two major advantages of aqueous batteries, which are the low cost and reduced environmental impact. Here we study alternative “Water-in-Salt” electrolytes (WiSE) based on highly concentrated sodium acetate and potassium acetate solutions. This kind of halide-free WiSE are studied by classical Molecular Dynamics (MD), evidencing the overall molecular arrangement to approach the “sponge-like” structure observed in certain ionic liquids and it offers wide electrochemical stability window and compatibility with stainless steel current collector. This is then employed as electrolyte in aqueous sodium-ion batteries featuring polyanionic compounds as active material. In-situ X-ray diffraction (XRD) experiments evidence the structural evolution during the reversible sodium de/intercalation. The X-ray photoemission spectroscopy (XPS) confirms the formation of a solid-electrolyte interphase (SEI) layer on the negative electrode. The cells show stable cycle performance and high coulombic efficiency above 99 % at 1C and 99.9% at 10C over 500 cycles.Keywords: Acetate-based, Water-in-Salt electrolyte, aqueous sodium-ion batteries, high coulombic efficiency

K2Fe3(SO4)3(OH)2(H2O)2: A new high-performance hydroxysulfate cathode material for alkali metal ion batteries

With advantages of safety benefits, high stability and tunable redox potentials, polyanionic electrode materials, especially sulfates draw lots of interests. Exploring general cathodes for alkali ion (Li, Na and K) battery is of great importance to understand the effect of ion size on materials’ electrochemical performance. Here, we report on a new K2Fe3(SO4)3(OH)2(H2O)2 sulfate as a promising cathode material for rechargeable alkali-ion batteries. Regardless of employing Li ions or large radius Na ions and K ions, the material manifests comparable capacities (~100 mA h•g−1) along with excellent rate behaviors (70 mA h•g−1 at 10C) and long lifetimes (~100% after 100 cycles at 1C). In addition, K2Fe3(SO4)3(OH)2(H2O)2 cathode delivers different electrochemical performances with three alkali ions, which is beneficial to understand the fundamental aspects of the reaction mechanisms. This work not only enriches the crystal chemistry of sulfate family, but also proposes a new design strategy to other K-based polyanionic compounds as cathode materials for Li ions and Na ions batteries.

Ultra-low-temperature aqueous batteries

Energy Storage The development of efficient electrochemical energy storage systems is of prime importance for future energy management, which will be increasingly based on renewable energy sources. Aqueous rechargeable alkali-ion batteries are particularly attractive for large-scale implementations given their environmentally friendly components and low cost. However, their low-temperature performance requires improvements, which can be achieved by optimizing the electrolyte's ionic conductivity and freezing point. Using dimethyl sulfoxide as the electrolyte additive, Nian et al. develop a new practical electrochemical system with electrolyte that freezes below −130°C. As a result, the battery operates with sufficient ionic conductivity even at −50°C. The reasons for such an ultra-low freezing point are analyzed by means of spectral characterization and molecular dynamics simulation. Angew. Chem. Int. Ed. 10.1002/anie.201908913 (2019).

Aqueous Batteries Operated at -50 °C.

Insufficient ionic conductivity and freezing of the electrolyte are considered the main problems for electrochemical energy storage at low temperatures (low T). Here, an electrolyte with a freezing point lower than -130 °C is developed by using dimethyl sulfoxide (DMSO) as an additive with molar fraction of 0.3 to an aqueous solution of 2 m NaClO4 (2M-0.3 electrolyte). The 2M-0.3 electrolyte exhibits sufficient ionic conductivity of 0.11 mS cm-1 at -50 °C. The combination of spectroscopic investigations and molecular dynamics (MD) simulations reveal that hydrogen bonds are stably formed between DMSO and water molecules, facilitating the operation of the electrolyte at ultra-low T. Using DMSO as the electrolyte additive, the aqueous rechargeable alkali-ion batteries (AABs) can work well even at -50 °C. This work provides a simple and effective strategy to develop low T AABs.

Tripling the Energy Density of Insertion-Type Electrode Materials for Rechargeable Alkali-Ion Batteries By Introducing Carefully Selected Dopants

Targeting continuously increasing energy and power densities for the next generations of rechargeable alkali-ion batteries like lithium-ion and sodium-ion batteries (LIBs and SIBs), researchers worldwide are trying to develop new electrode materials which are capable of hosting more lithium/sodium ions per unit weight or volume.[1]–[4] Ideally, these new materials also allow for a fast delithiation/desodiation and, even more important, lithiation/sodiation, i.e., the charge step. This is a particular challenge for insertion-type materials, which are commonly used at present in commercial LIBs. In fact, it is frequently written that the insertion mechanism sets an intrinsic limit to the achievable lithium storage capacity. Herein, we show that the introduction of carefully selected dopants provides the chance to double or even triple the capacity of insertion-type lithium- and sodium-ion anodes. Based on an in-depth characterization down to the atomic scale, we will moreover provide general guidelines for achieving such improvement and, eventually, present also their employment in high-performance lithium-ion and sodium-ion full-cells, offering an outstanding combination of high energy and high power, as shown in Figure 1 and Table 1. [5]–[12] References [1] B. Scrosati, J. Garche, J. Power Sources 2010, 195, 2419. [2] M.S. Whittingham, Chem. Rev. 2004, 104, 4271. [3] N. Loeffler, D. Bresser, S. Passerini, M. Copley, Johns. Matthey Technol. Rev. 2015, 59, 34. [4] J.-Y. Hwang, S.-T. Myung, Y.-K. Sun, Chem. Soc. Rev. 2017, 46, 3529. [5] X. Su, J. Liu, C. Zhang, T. Huang, Y. Wang, A. Yu, RSC Adv. 2016, 6, 107355. [6] X. Sun, X. Zhang, B. Huang, H. Zhang, D. Zhang, Y. Ma, J. Power Sources 2013, 243, 361. [7] A. Varzi, D. Bresser, J. von Zamory, F. Müller, S. Passerini, Adv. Energy Mater. 2014, 4, 1400054. [8] W. Wang, D. Choi, Z. Yang, Metall. Mater. Trans. A 2013, 44, 21. [9] L. Shen, H. Lv, S. Chen, P. Kopold, P.A. van Aken, X. Wu, J. Maier, Y. Yu, Adv. Mater. 2017, 29, 1700142. [10] H. Kim, M.-Y. Cho, M.-H. Kim, K.-Y. Park, H. Gwon, Y. Lee, K.C. Roh, K. Kang, Adv. Energy Mater. 2013, 3, 1500. [11] V. Aravindan, J. Sundaramurthy, A. Jain, P.S. Kumar, W.C. Ling, S. Ramakrishna, M.P. Srinivasan, S. Madhavi, ChemSusChem 2014, 7, 1858. [12] J. Xu, Y. Li, L. Wang, Q. Cai, Q. Li, B. Gao, X. Zhang, K. Huo, P.K. Chu, Nanoscale 2016, 8, 16761. Figure 1

Carbon nanoparticle-based three-dimensional binder-free anode for rechargeable alkali-ion batteries

We demonstrate a simple and effective method for the fabrication of three-dimensional (3D) binder-free carbon anode using biomass as a carbon source. The anode consisted of interconnected carbon nanoparticles self-assembled onto a nickel foam substrate, providing easy electrolyte access throughout the electrode. The unique 3D electrode architecture prevented deformation of the electrode during cycling. The absence of binder and conducting additive simplifies the electrode fabrication process, thus lowering the battery fabrication costs. As a proof of concept, the anode when tested against lithium delivered a specific discharge capacity of 764 mA h g−1 at a current density of 50 mA g−1, with an exceptional cycling stability at high current rates (e.g., delivering a capacity of 664 mA h g−1 at 500th cycle at a current density of 1 A g−1). Furthermore, the anode was also tested against sodium, exhibiting a reversible discharge capacity of 241 mA h g−1 in the second cycle at a current density of 50 mA g−1 and remained stable over prolonged cycling. The ion storage mechanism was studied using ex-situ spectroscopic techniques.

Thermodynamics and Kinetics of Alkali Insertion in VOPO4 Polymorphs

Multi-electron polyanion cathodes offer the potential for achieving both high voltage and high capacity in rechargeable alkali-ion batteries. Among the few materials known to exhibit multi-electron cycling, the polymorphs of VOPO4 , which operate on the V3+«V4+«V5+ redox couples, are particularly promising due to the high gravimetric capacities that have been achieved and the high voltage of the V4+/ 5+ couple. In this talk, we will provide an integrated computational and experimental study of the thermodynamics and kinetics of alkali (Li/Na) insertion into the α-I, β and ε polymorphs of VOPO4. We show that differences in voltage and rate capability of these different polymorphs for Li and Na insertion can be traced back to their fundamentally different VO6-PO4 frameworks. We will also provide an overview of the different contributions to the thermodynamic stability of the different polymorphs. This work was supported as part of the NorthEast Center for Chemical Energy Storage (NECCES), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0012583.

Design and Optimization of Novel Alkali Superionic Conductors

All solid-state rechargeable alkali-ion batteries are a safer, potentially more energy dense architecture for energy storage. The crucial enabling component is the non-flammable alkali superionic conductor solid electrolyte, which must possess high alkali ionic conductivity, excellent phase stability, electrochemical and mechanical compatibility with the electrodes, and ideally, stability under ambient air. Despite recent advances, the total number of known alkali superionic conductors remain relatively small, and most have significant compromises. In this talk, we will propose several promising novel alkali superionic conductor solid electrolytes - Li3Y(PS4)2 and Li5PS4Cl2 - identified using an efficiently-tiered first principles screening approach. These candidates are inspired by the observation that many known alkali superionic conductors have analogues in the silver thiophosphate chemical space (e.g., Li7P3S11, the Li6PS5X argyrodites, etc.). We will also present evidence that these candidates may potentially have a better balance of properties, especially with regards to phase and electrochemical stability, compared to current state-of-the-art superionic conductors such as Li10GeP2S12, Li9.54Si1.74P1.44S 11.7Cl0.3 and Li7P3S11.

Comparison of the polymorphs of VOPO4 as multi-electron cathodes for rechargeable alkali-ion batteries

VO6/VO5–PO4 frameworks govern electrochemical performance in VOPO4 polymorphs.