Rechargeable aqueous zinc-ion batteries are highly desirable for grid-scale applications due to their low cost and high safety; however, the poor cycling stability hinders their widespread application Herein, a highly durable zinc-ion battery system with a Na2V6O16·163H2O nanowire cathode and an aqueous Zn(CF3SO3)2 electrolyte has been developed The Na2V6O16·163H2O nanowires deliver a high specific capacity of 352 mAh g–1 at 50 mA g–1 and exhibit a capacity retention of 90% over 6000 cycles at 5000 mA g–1, which represents the best cycling performance compared with all previous reports In contrast, the NaV3O8 nanowires maintain only 17% of the initial capacity after 4000 cycles at 5000 mA g–1 A single-nanowire-based zinc-ion battery is assembled, which reveals the intrinsic Zn2+ storage mechanism at nanoscale The remarkable electrochemical performance especially the long-term cycling stability makes Na2V6O16·163H2O a promising cathode for a low-cost and safe aqueous zinc-ion battery

Highly Durable Na2V6O16·1.63H2O Nanowire Cathode for Aqueous Zinc-Ion Battery

Tremendous efforts have been devoted to the development of electrode materials, electrolytes, and separators of energy-storage devices to address the fundamental needs of emerging technologies such as electric vehicles, artificial intelligence, and virtual reality. However, binders, as an important component of energy-storage devices, are yet to receive similar attention. Polyvinylidene fluoride (PVDF) has been the dominant binder in the battery industry for decades despite several well-recognized drawbacks, i.e., limited binding strength due to the lack of chemical bonds with electroactive materials, insufficient mechanical properties, and low electronic and lithium-ion conductivities. The limited binding function cannot meet inherent demands of emerging electrode materials with high capacities such as silicon anodes and sulfur cathodes. To address these concerns, in this review we divide the binding between active materials and binders into two major mechanisms: mechanical interlocking and interfacial b...

Exploring Chemical, Mechanical, and Electrical Functionalities of Binders for Advanced Energy-Storage Devices

The increasing demand for replacing conventional fossil fuels with clean energy or economical and sustainable energy storage drives better battery research today. Sodium-ion batteries (SIBs) are considered as a promising alternative for grid-scale storage applications due to their similar “rocking-chair” sodium storage mechanism to lithium-ion batteries, the natural abundance, and the low cost of Na resources. Searching for appropriate electrode materials with acceptable electrochemical performance is the key point for development of SIBs. Layered transition metal oxides represent one of the most fascinating electrode materials owing to their superior specific capacity, environmental benignity, and facile synthesis. However, three major challenges (irreversible phase transition, storage instability, and insufficient battery performance) are known for cathodes in SIBs. Herein, a comprehensive review on the latest advances and progresses in the exploration of layered oxides for SIBs is presented, and a detailed and deep understanding of the relationship of phase transition, air stability, and electrochemical performance in layered oxide cathodes is provided in terms of refining the structure–function–property relationship to design improved battery materials. Layered oxides will be a competitive and attractive choice as cathodes for SIBs in next-generation energy storage devices.

Layered Oxide Cathodes for Sodium-Ion Batteries: Phase Transition, Air Stability, and Performance

The tremendous improvement in performance and cost of lithium-ion batteries (LIBs) have made them the technology of choice for electrical energy storage. While established battery chemistries and cell architectures for Li-ion batteries achieve good power and energy density, LIBs are unlikely to meet all the performance, cost, and scaling targets required for energy storage, in particular, in large-scale applications such as electrified transportation and grids. The demand to further reduce cost and/or increase energy density, as well as the growing concern related to natural resource needs for Li-ion have accelerated the investigation of so-called "beyond Li-ion" technologies. In this review, we will discuss the recent achievements, challenges, and opportunities of four important "beyond Li-ion" technologies: Na-ion batteries, K-ion batteries, all-solid-state batteries, and multivalent batteries. The fundamental science behind the challenges, and potential solutions toward the goals of a low-cost and/or high-energy-density future, are discussed in detail for each technology. While it is unlikely that any given new technology will fully replace Li-ion in the near future, "beyond Li-ion" technologies should be thought of as opportunities for energy storage to grow into mid/large-scale applications.

/pdf/promises-and-challenges-of-next-generation-beyond-li-ion-3uqzf9jz9t.pdf

Promises and challenges of next-generation "beyond Li-ion" batteries for electric vehicles and grid decarbonization

Sodium-ion batteries (SIBs) have attracted increasing attention in the past decades, because of high overall abundance of precursors, their even geographical distribution, and low cost. Apart from inherent thermodynamic disadvantages, SIBs have to overcome multiple kinetic problems, such as fast capacity decay, low rate capacities and low Coulombic efficiencies. A special case is sodium super ion conductor (NASICON)-based electrode materials as they exhibit - besides pronounced structural stability - exceptionally high ion conductivity, rendering them most promising for sodium storage. Owing to the limiting, comparatively low electronic conductivity, nano-structuring is a prerequisite for achieving satisfactory rate-capability. In this review, we analyze advantages and disadvantages of NASICON-type electrode materials and highlight electrode structure design principles for obtaining the desired electrochemical performance. Moreover, we give an overview of recent approaches to enhance electrical conductivity and structural stability of cathode and anode materials based on NASICON structure. We believe that this review provides a pertinent insight into relevant design principles and inspires further research in this respect.

Challenges and Perspectives for NASICON-Type Electrode Materials for Advanced Sodium-Ion Batteries

Sodium-ion batteries, representative members of the post-lithium-battery club, are very attractive and promising for large-scale energy storage applications. The increasing technological improvements in sodium-ion batteries (Na-ion batteries) are being driven by the demand for Na-based electrode materials that are resource-abundant, cost-effective, and long lasting. Polyanion-type compounds are among the most promising electrode materials for Na-ion batteries due to their stability, safety, and suitable operating voltages. The most representative polyanion-type electrode materials are Na3V2(PO4)3 and NaTi2(PO4)3 for Na-based cathode and anode materials, respectively. Both show superior electrochemical properties and attractive prospects in terms of their development and application in Na-ion batteries. Carbonophosphate Na3MnCO3PO4 and amorphous FePO4 have also recently emerged and are contributing to further developing the research scope of polyanion-type Na-ion batteries. However, the typical low conductivity and relatively low capacity performance of such materials still restrict their development. This paper presents a brief review of the research progress of polyanion-type electrode materials for Na-ion batteries, summarizing recent accomplishments, highlighting emerging strategies, and discussing the remaining challenges of such systems.

/pdf/polyanion-type-electrode-materials-for-sodium-ion-batteries-acaq5slqjx.pdf

Polyanion-Type Electrode Materials for Sodium-Ion Batteries.

The development of portable and wearable electronics has aroused the increasing demand for flexible energy-storage devices, especially for the characteristics of high energy density, excellent mechanical properties, simple synthesis process, and low cost. However, the development of flexible electrodes for sodium-ion batteries (SIBs) is still limited due to the intricate production methods and the relatively high-cost of current collectors such as graphene/graphene oxide and carbon nanotubes. Here, the hierarchical 3D electronic channels wrapped large-sized Na3 V2 (PO4 )3 is designed and fabricated by a simple electrospinning technique. As flexible electrode material, it exhibits outstanding electrolyte wettability, together with ultrafast electronic conductivity and high Na-ion diffusion coefficients for SIBs, leading to superior electrochemical performances. A high reversible specific capacity of 116 mA h g-1 (nearly 99% of the theoretical specific capacities) can be obtained at the current density of 0.1 C. Even after a 300-fold current density increased (30 C), the discharge specific capacity of the flexible electrode still remains 63 mA h g-1 . Such an effective concept of fabricating 3D electronic channels for large-sized particles is expected to accelerate the practical applications of flexible batteries at various systems.

3D Electronic Channels Wrapped Large-Sized Na3V2(PO4)3 as Flexible Electrode for Sodium-Ion Batteries

Superior sodium-storage behavior of flexible anatase TiO2 promoted by oxygen vacancies

In order to get an element substituted into Na3V2(PO4)3/C in an appointed V site, the simple sol–gel method is used to design and prepare a series of Na-rich Na3+xV2–xNix(PO4)3/C (x = 0–0.07) compounds. To get a charge balance, the ratio of Na, V, and Ni would be changed if Ni goes into a different site. Hence, ICP is applied to probe the real stoichiometry of the as-prepared Na3+xV2–xNix(PO4)3/C (x = 0–0.07). According to the Na/V ratio from the ICP result, it indicates that Ni2+ goes to a V site, and more Na+ will be introduced into the crystal to keep the charge balance. In addition, the crystal structure changes are explored by XRD and Rietveld refinement, it is indicated from the results that Ni2+ doping does not destroy the lattice structure of Na3V2(PO4)3. When applied as Na-storage material, the electrochemical property of all Ni2+ doped Na3+xV2–xNix(PO4)3/C composites have been significantly improved, especially for the Na3.03V1.97Ni0.03(PO4)3/C sample. For example, 107.1 mAh g–1 can be obtained ...

Na-Rich Na3+xV2-xNix(PO4)3/C for Sodium Ion Batteries: Controlling the Doping Site and Improving the Electrochemical Performances.

Sodium alginate (SA) is investigated as the aqueous binder to fabricate high-performance, low-cost, environmentally friendly, and durable TiO2 anodes in sodium-ion batteries (SIBs) for the first time. Compared to the conventional polyvinylidene difluoride (PVDF) binder, electrodes using SA as the binder exhibit significant promotion of electrochemical performances. The initial Coulombic efficiency is as high as 62% at 0.1 C. A remarkable capacity of 180 mAh g–1 is achieved with no decay after 500 cycles at 1 C. Even at 10 C (3.4 A g–1), it remains 82 mAh g–1 after 3600 cycles with approximate 100% Coulombic efficiency. TiO2 electrodes with SA binder display less electrolyte decomposition, fewer side reactions, high electrochemistry reaction activity, effective suppression of polarization, and good electrode morphology, which is ascribed to the rich carboxylic groups, high Young’s modulus, and good electrochemical stability of SA binder.

Qiao Ni

Papers

Polyanion-Type Electrode Materials for Sodium-Ion Batteries.

3D Electronic Channels Wrapped Large-Sized Na3V2(PO4)3 as Flexible Electrode for Sodium-Ion Batteries

Superior sodium-storage behavior of flexible anatase TiO2 promoted by oxygen vacancies

Na-Rich Na3+xV2-xNix(PO4)3/C for Sodium Ion Batteries: Controlling the Doping Site and Improving the Electrochemical Performances.

Remarkable Effect of Sodium Alginate Aqueous Binder on Anatase TiO2 as High-Performance Anode in Sodium Ion Batteries