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The realization of high energy density and fast-charging capability is severely limited by the low intrinsic electronic conductivity and slow ion diffusion rates for the Na3V2(PO4)2O2F (NVPOF) cathode in sodium-ion batteries (SIBs). Inspired by the rapid transport of carriers in two-dimensional (2D) frames, we designed a carbonless fast-charging 2D-NVPOF cathode material using H2O molecules as the initial green exfoliant for the first time, which achieves the breakage of strong interlayer ionic bonds under mild and safe conditions. After exfoliation operation via mechanical expansion with the assistance of a thermal field, the H2O molecules can enter into interlayers of 2D-NVPOF and further coordinate with the defective V atoms, thus enhancing the electronic conductivity, structural robustness and Na+ diffusion kinetics, which can be verified from the enhanced (002) lattice plane exposure, reduced band gap and lower Na+ migration energy barrier of 2D-NVPOF. In concert, these merits contribute to achieving the excellent fast-charging properties (80% of total battery capacity in 120 s of charging), higher energy density (up to 465 W h kg−1), and long-term cycling stability of 2D-NVPOF, highlighting the great potential for practical application in SIBs. This strategy implies that the enhancement of electronic/ionic conductivity in the NASICON structure is achievable without introducing carbon and altering the active center, thus sparking new ideas for improving the fast-charging characteristics of cathodes for SIBs. [ABSTRACT FROM AUTHOR]

The NASICON cathode, Na3V2(PO4)3, has garnered significant attention due to its robust framework with fast Na+ migration. To expand its application scenarios by diversified electronic reaction, the substitution of vanadium with cost‐effective and abundant redox elements is a special research topic. Nevertheless, in terms of reducing toxicity, increasing Na content and widening voltage range, the V4+/5+ redox couple in Na4FeV(PO4)3 often accompanies asymmetric and irreversible electrochemical reactions that pose a dilemma for capacity and structural stability, especially at high currents. Herein, in this work, Na4FeV1/3Ti2/3(PO4)3 (NFVT) has achieved highly reactive of multiple electron transfer (Ti2+/3+, Fe2+/3+, and V3+/4+/5+) by utilizing the redox reaction with quasi‐monophase behavior, and it can reserve great capacity retention after 3,000 cycles. More competitively, its boosting kinetics makes the fast‐charging characteristic, just requiring only 3.63 min to reach 80% state of charge at 2 C. The rapid ion/electron transport dynamics can achieve the decay of only 0.043% per cycle by unlocking the quasi‐monophase behavior in the framework of NFVT full cells. The present study provides a fresh perspective on designing cathode materials with fast‐charging capabilities for sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

2D compounds exfoliated from weakly bonded bulk materials with van der Waals (vdW) interaction are easily accessible. However, the strong internal ionic/covalent bonding of most inorganic crystal frameworks greatly hinders 2D material exfoliation. Herein, we first proposed a radical/strain‐synergistic strategy to exfoliate non‐vdW interacting pseudo‐layered phosphate framework. Specifically, hydroxyl radicals (⋅OH) distort the covalent bond irreversibly, meanwhile, H2O molecules as solvents, further accelerating interlayered ionic bond breakage but mechanical expansion. The innovative 2D laminar NASICON‐type Na3V2(PO4)2O2F crystal, exfoliated by ⋅OH/H2O synergistic strategy, exhibits enhanced sodium‐ion storage capacity, high‐rate performance (85.7 mAh g−1 at 20 C), cyclic life (2300 cycles), and ion migration rates, compared with the bulk framework. Importantly, this chemical/physical dual driving technique realized the effective exfoliation for strongly coupled pseudo‐layered frameworks, which accelerates 2D functional material development. [ABSTRACT FROM AUTHOR]

Potassium-ion batteries (PIBs) have emerged as promising candidates for cost-effective and sustainable energy-storage systems. Nevertheless, limited by the large K+ radius, PIBs have great difficulty in figuring out and designing suitable host materials. Herein, a suitable cathode material K3V2(PO4)2O2F (KVPOF) for PIBs has been carefully prepared. It exhibits a high specific capacity close to the theoretical value, 116.3 mAh/g at 20 mA/g within the voltage window of 2.0–4.5 V vs K+/K, corresponding to a de-/intercalation process of ∼2 mol K+ per formula unit. In addition, it presents an average operating voltage plateau of about 3.5 V, resulting in an energy density of about 410 Wh/kg. The crystal structure and phase transition are revealed by in situ x-ray diffraction, and the structure is found to be fully reversible during the de-/intercalation of K+. Furthermore, the potential of KVPOF cathode for applications at low temperatures was explored, and the full cell matched with graphite anode demonstrated fair electrochemical performance. The experimental results suggest the feasibility of using KVPOF as cathode material for rechargeable PIBs. [ABSTRACT FROM AUTHOR]

The rapid developments of the Internet of Things (IoT) and portable electronic devices have created a growing demand for flexible electrochemical energy storage (EES) devices. Nevertheless, these flexible devices suffer from poor flexibility, low energy density, and poor dynamic stability of power output during deformation, limiting their practical applications. Carbon nanofibers (CNFs) with high conductivity, good flexibility, and large‐scale preparation are regarded as promising electrodes for flexible EES devices. Based on the issues of current flexible EES devices, this review presents various strategies from the design of CNFs‐based electrodes to the fabrication of devices and overviews their applications in various flexible metal ion/air batteries (Li/Na/K‐ion batteries, Li‐S batteries, metal–air batteries, and other novel secondary batteries) and supercapacitors. Finally, the remaining challenges and perspectives on the CNFs‐based flexible EES devices are proposed to provide guidance for the researchers concentrating on high‐performance flexible EES devices. [ABSTRACT FROM AUTHOR]

The apparent digestibility coefficients (ADCs) of Tenebrio molitor meal (TMM), Hermetia illucens meal (HIM), Clostridium autoethanogenum protein (CAP), Methylococcus capsulatus meal (MCM), Chlorella vullgaris meal (CVM), Cottonseed protein concentrate (CPC) and Peruvian fishmeal (PFM) were determined in juvenile hybrid grouper (Epinephelus fuscoguttatus♀xEpinephelus lanceolatu♂). A basal diet (including 50% fishmeal) and seven test diets (700 g/kg of the basal diet and 300 g/kg of each test ingredient) were formulated with 0.1% yttrium oxide (Y2O3) as an inert marker. The juvenile hybrid groupers, with initial average body weight of (9.95±0.50) g, were randomly distributed into 0.3 m³ fiberglass tanks, each tank with 30 fish. The faeces samples were collected twice-daily by siphoning following feeding fish after five days of domestication. The ADCs of dry matter of seven test ingredients were ranked as CVM>TMM=CAP=CPC>HIM=MCM=PFM (P<0.05). CVM showed the highest ADCs of dry matter (DM), crude protein (CP) and most amino acids (including methionine and threonine) except crude lipids (CL), whereas HIM had the relatively lower ADCs of DM, CP and most amino acids except CL. CAP had a higher lysine digestibility than the other six test ingredients, and was only lower than CVM in the ADC of CP. The ADC of DM in PFM was significantly lower than that in CVM (P<0.05), and showed no differences with that in CAP (P>0.05). Besides, PFM showed a lower ADC of CP than the ADCs of CP in CVM, CAP and MCM (P<0.05), and showed a lower ADC of lysine than that in CAP as well as a lower ADC of threonine than those in CAP and CVM (P<0.05). Overall, this study showed the advantage of CVM and CAP among the seven protein sources on the digestibility of feed available in hybrid grouper. [ABSTRACT FROM AUTHOR]

Hybrid lithium-ion capacitors (LICs) receive special interests because they work by combining the merits of high-capacity lithium-ion batteries and high-rate capacitors in a Li salt containing electrolyte, so as to bridge the gap between the two devices. One of main challenges for LICs is to develop inexpensive and superior anode materials at high rates. In this work, natural molybdenite was utilized as precursor to achieve the scalable production of cheap MoS2/carbon composites. This molybdenite-derived MoS2/carbon electrode can not only exhibit excellent Li+-storage performances including ultrahigh specific capacity (1427 mAh gâ€"1 after 1000 cycles at 1 A gâ€"1) and rate capability (554 mAh gâ€"1 at 10 A gâ€"1), but also possess four-times higher tap density than that of commercial graphite. By employing MoS2/carbon as the anode and activated carbon as the cathode, the as-assembled LIC device delivers both high energy//high power density and long cycle lifespan. Furthermore, the price is nearly 200 orders of magnitude lower than the traditional high-purity chemicals, which can be easily scaled up to achieve high-throughput production. [ABSTRACT FROM AUTHOR]

A recent research article in Angewandte Chemie International Edition discusses a new method for creating a 2D phosphate material with improved properties for use in sodium-ion battery cathodes. The researchers used radicals and water molecules to break V-F-V bonds in bulk phase phosphate, resulting in the formation of a new 2D phosphate through recoordination. This 2D phosphate demonstrated enhanced carrier transport capability, lower Na+ migration barriers, and reduced volumetric strain, making it ideal for fast charging in sodium-ion batteries. The findings of this study offer valuable insights for the optimization of sodium-ion batteries. [Extracted from the article]

A recent research article in Angewandte Chemie discusses a new method for creating a 2D phosphate material with improved properties for use in sodium-ion battery cathodes. The researchers used radicals and water molecules to break V-F-V bonds in bulk phase phosphate, resulting in the formation of a new 2D phosphate structure. This new material demonstrated enhanced carrier transport capability, lower Na+ migration barriers, and reduced volumetric strain, making it ideal for fast charging in sodium-ion batteries. The findings of this study offer valuable insights for optimizing sodium-ion batteries. [Extracted from the article]