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Abstract Rechargeable batteries are highly in demand to power various electronic devices and future smart electric grid energy storage. The electrode–electrolyte interphases play a crucial role in influencing the electrochemical performance of batteries, with the solvation chemistries of the electrolyte being particularly significant in regulating these interfacial reactions. However, the reaction mechanisms of electrolyte solvation and their specific functions in batteries are not yet fully understood. In this review, we embark on an exploration of the fundamental principles governing solvation and present a comprehensive overview of how solvation structures impact interfacial reactions at the electrode–electrolyte interface. We underscore the significance of interactions among cations, anions, and solvents in shaping electrolyte solvation structures. The primary strategies for controlling solvation structures are also discussed, including the optimization of salt concentrations, solvent interactions, and the introduction of functional cosolvents. Furthermore, we elucidate the oxidation/reduction reaction mechanisms of electrolyte components in different solvation structures and the new understanding of electrolyte additives in modulating interfacial chemistries in batteries. Additionally, we emphasize the importance of incorporating new characterization techniques and theoretical simulations to attain a deeper understanding of the intricate processes taking place within batteries. This review provides an in‐depth understanding in solvations and interphasial properties and new ideas for designing advanced functional electrolytes for rechargeable batteries.

Abstract Understanding the structural origin of the competition between oxygen 2p and transition‐metal 3d orbitals in oxygen‐redox (OR) layered oxides is eminently desirable for exploring reversible and high‐energy‐density Li/Na‐ion cathodes. Here, we reveal the correlation between cationic ordering transition and OR degradation in ribbon‐ordered P3‐Na0.6Li0.2Mn0.8O2 via in situ structural analysis. Comparing two different voltage windows, the OR capacity can be improved approximately twofold when suppressing the in‐plane cationic ordering transition. We find that the intralayer cationic migration is promoted by electrochemical reduction from Mn4+ to Jahn–Teller Mn3+ and the concomitant NaO6 stacking transformation from triangular prisms to octahedra, resulting in the loss of ribbon ordering and electrochemical decay. First‐principles calculations reveal that Mn4+/Mn3+ charge ordering and alignment of the degenerate eg orbital induce lattice‐level collective Jahn–Teller distortion, which favors intralayer Mn‐ion migration and thereby accelerates OR degradation. These findings unravel the relationship between in‐plane cationic ordering and OR reversibility and highlight the importance of superstructure protection for the rational design of reversible OR‐active layered oxide cathodes.

The implementation of Li metal anode with high-voltage Ni/Co rich cathode is plagued by low coulombic efficiency and inferior cycling stability. Here authors propose an anion-enriched interface to facilitate the columnar-structure of Li deposits to solve this issue.

The anionic redox reaction (ARR) is a promising charge contributor to improve the reversible capacity of layered-oxide cathodes for Na-ion batteries; however, some practical bottlenecks still need to be eliminated, including a low capacity retention, large voltage hysteresis, and low rate capability. Herein, we proposed a high-Na content honeycomb-ordered cathode, P2–Na5/6[Li1/6Cu1/6Mn2/3]O2 (P2-NLCMO), with combined cationic/anionic redox. Neutron powder diffraction and X-ray diffraction of P2-NLCMO suggested P2-type stacking with rarely found P6322 symmetry. In addition, advanced spectroscopy techniques and density functional theory calculations confirmed the synergistic stabilizing relationship between the Li/Cu dual honeycomb centers, achieving fully active Cu3+/Cu2+ redox and stabilized ARR with interactively suppressed local distortion. With a meticulously regulated charge/discharge protocol, both the cycling and rate capability of P2-NLCMO were significantly improved, demonstrating reasonable capacity and eliminating voltage hysteresis. Overall, this work contributes a well-defined layered oxide cathode with combined cationic/anionic redox towards rational designing advanced Na-ion batteries.

Experimentally probing the orbital population is highly desirable to resolve the redox mechanism of cathodes materials. Here the authors quantify the orbital populations of Co and O in LiCoO2 and identify the ligand-to-metal charge transfer.

Abstract Although it has been proven that porous, heteroatomic, and defective structures improve Na storage performance, they also severely affect the initial Coulombic efficiency (ICE) due to the huge irreversible capacity in the first cycle, which always limits the practical application of carbon anodes in commercial Na‐ion batteries (NIBs). Here, we show the successful synthesis of nanocrystalline cellulose and the derivative hard carbons. A series of treatments including acid hydrolysis, hydrothermal carbonization, and high‐temperature pyrolysis help tune the pores, heteroatoms, and defects to achieve an optimized balance between superior ICE and reversible capacity of up to 90.4% and 314 mAh g−1. This study highlights that tailoring the electrode microstructure could be an important strategy in the future design of carbonaceous anode materials for high‐performance Na‐ion batteries.

Abstract A surge of interest has been brought to all‐solid‐state batteries (ASSBs) as they show great prospects for enabling higher energy density and improved safety compared to conventional liquid batteries. Na Super Ionic CONductors (NaSICONs) proposed by Goodenough and Hong in 1976 are the most promising materials class for Na‐based ASSBs owing to their excellent ion conductivity (>1 mS cm−1), high thermal and chemical/electrochemical stability, as well as good chemical/electrochemical compatibility with electrode materials. The major challenge facing NaSICON‐type electrolytes is the generally high interfacial resistance and thus sluggish charge transfer kinetics across the NaSICON/cathode interface. Great endeavors in the past few years have led to progress in the improvement of the ion‐conducting property, and a dramatic decrease in the NaSICON/electrode interface resistance. Excellent cycling performance and rate capability have been achieved through interface engineering. In this review article, we summarize the state‐of‐the‐art findings for various derivatives of NaSICON structured solid electrolytes, with the aim of providing a deeper understanding of the underlying mechanism for the improvement of ion conductivity, and the intrinsic reasons for the enhanced interface charge transfer kinetics. These strategies can be readily extended to other solid electrolytes. We hope this review will inspire more work on NaSICON‐type solid electrolytes and solid‐state batteries.

Solid-state polymer electrolytes are crucial for developing future rechargeable batteries, but they are still limited in performance. Here, the authors designed a topological polymeric solid electrolyte, enabling an all-solid-state high-voltage lithium metal pouch cell to cycle 200 times efficiently.

The low ionic conductivity of solid-state electrolytes (SSEs) and the inferior interfacial reliability between SSEs and solid-state electrodes are two urgent challenges hindering the application of solid-state sodium batteries (SSSBs). Herein, sodium (Na) super ionic conductor (NASICON)-type SSEs with a nominal composition of Na3+2xZr2–xMgxSi2PO12 were synthesized using a facile two-step solid-state method, among which Na3.3Zr1.85Mg0.15Si2PO12 (x = 0.15, NZSP-Mg0.15) showed the highest ionic conductivity of 3.54 mS∙cm−1 at 25 °C. By means of a thorough investigation, it was verified that the composition of the grain boundary plays a crucial role in determining the total ionic conductivity of NASICON. Furthermore, due to a lack of examination in the literature regarding whether NASICON can provide enough anodic electrochemical stability to enable high-voltage SSSBs, we first adopted a high-voltage Na3(VOPO4)2F (NVOPF) cathode to verify its compatibility with the optimized NZSP-Mg0.15 SSE. By comparing the electrochemical performance of cells with different configurations (low-voltage cathode vs high-voltage cathode, liquid electrolytes vs SSEs), along with an X-ray photoelectron spectroscopy evaluation of the after-cycled NZSP-Mg0.15, it was demonstrated that the NASICON SSEs are not stable enough under high voltage, suggesting the importance of investigating the interface between the NASICON SSEs and high-voltage cathodes. Furthermore, by coating NZSP-Mg0.15 NASICON powder onto a polyethylene (PE) separator (PE@NASICON), a 2.42 A∙h non-aqueous Na-ion cell of carbon|PE@NASICON|NaNi2/9Cu1/9Fe1/3Mn1/3O2 was found to deliver an excellent cycling performance with an 88% capacity retention after 2000 cycles, thereby demonstrating the high reliability of SSEs with NASICON-coated separator.

Abstract Ni‐rich layered (NRL) cathodes have been widely considered to undergo a degeneration from layered to spinel‐like phases and finally to a rock−salt phase, which jeopardizes the battery's performance and safety. However, this process does not sufficiently explain the drastic structure collapse that occurs during thermal runaway, as the lattice constants of these structures are similar. Herein, an intermediate β‐Li2NiO3 phase is identified during the thermally driven structural evolution via in situ heating scanning transmission electron microscopy imaging. The antihoneycomb‐ordered structure leads to a larger lattice mismatch of up to ∼15% with the layered structure. The resulting strain triggers huge bulk stress and the labile oxygen of the β‐Li2NiO3 phase aggravates the oxygen release, severely reducing the thermal stability of NRL materials. Finally, based on the screening for 3d transition metals, doping elements are chosen to suppress the β‐Li2TMO3 phase and enhance thermal stability. The findings provide comprehensive insights into the structural degradation process of NRL materials and pave the way to design high‐performance and safe battery systems.

The high production cost and poor electrochemical performance of polyanionic cathode hinders their industrial application. Here, the authors report large-scale fabrication of sodium vanadium fluorophosphates and in situ construction of their carbon nanocomposites via a mechanochemical protocol.

Interface chemistry is essential for highly reversible lithium-metal batteries. Here the authors investigate amide-based electrolyte that lead to desirable interface species, resulting in dense Li-metal plating and top-down Li-metal stripping, responsible for the highly reversible cycling.

Abstract Flexible energy storage devices have gained significant attention because of the increasing needs of bendable displays, wearable electronics, and flexible displays. Flexible Na‐based rechargeable batteries are the promising power sources in such products due to their low cost and wide availability. In this review, we firstly introduce the structural superiority of flexible Na‐based batteries and summarize their main components including cathodes, electrolytes, and anodes. Moreover, fabrication of their flexible components is discussed in detail, with specific emphasis on material selection, particularly for solid‐state electrolytes. This is followed by an overview highlighting recent progress in the development of prototypes of flexible Na‐ion batteries and beyond. Finally, perspectives on future challenges for the development of flexible Na batteries are proposed.

Na-ion batteries (NIBs) have received significant interest as potential candidates for large-scale energy storage owing to the widespread distribution of sodium and superior low-temperature performance. However, their commercial application is usually hindered by the high production cost and inadequate performance for electrode materials, particularly for cathodes. Na3(VOPO4)2F (NVOPF) has been recognized as one of the most promising cathodes for high-energy NIBs owing to the high working voltage and energy density. Here, we report a facile highly efficient room-temperature solution protocol for large-scale synthesis of NVOPF cathode for NIBs. By simply regulating pH, NVOPF can be obtained, which delivered a discharge capacity of 120.2 mAh g-1 at 0.1 C and 72% capacity retention over 8000 cycles at 25 C. Besides, the kilogram-level NVOPF products have been synthesized, and 26650 cylindrical cells were fabricated, which exhibit excellent cycling stabilities, remarkable low-temperature performance with comparable safety features. We hope our findings could provide insights on the industrial application of NVOPF in NIBs.

The growing concern about scarcity and large-scale applications of lithium resources has attracted efforts to realize cost-effective phosphate-based cathode materials for next-generation Na-ion batteries (NIBs). In previous work, a series of materials (such as Na _4 Fe _3 (PO _4 ) _2 (P _2 O _7 ), Na _3 VCr(PO _4 ) _3 , Na _4 VMn(PO _4 ) _3 , Na _3 MnTi(PO _4 ) _3 , Na _3 MnZr(PO _4 ) _3 , etc) with ∼120 mAh g ^−1 specific capacity and high operating potential has been proposed. However, the mass ratio of the total transition metal in the above compounds is only ∼22 wt%, which means that one-electron transfer for each transition metal shows a limited capacity (the mass ratio of Fe is 35.4 wt% in LiFePO _4 ). Therefore, a multi-electron transfer reaction is necessary to catch up to or go beyond the electrochemical performance of LiFePO _4 . This review summarizes the reported NASICON-type and other phosphate-based cathode materials. On the basis of the aforementioned experimental results, we pinpoint the multi-electron behavior of transition metals and shed light on designing rules for developing high-capacity cathodes in NIBs.

NASICON- (Na superionic conductor-) based solid-state electrolytes (SSEs) are believed to be attracting candidates for solid-state sodium batteries due to their high ionic conductivity and prospectively reliable stability. However, the poor interface compatibility and the formation of Na dendrites inhibit their practical application. Herein, we directly observed the propagation of Na dendrites through NASICON-based Na3.1Zr2Si2.1P0.9O12 SSE for the first time. Moreover, a fluorinated amorphous carbon (FAC) interfacial layer on the ceramic surface was simply developed by in situ carbonization of PVDF to improve the compatibility between Na metal and SSEs. Surprisingly, Na dendrites were effectively suppressed due to the formation of NaF in the interface when molten Na metal contacts with the FAC layer. Benefiting from the optimized interface, both the Na||Na symmetric cells and Na3V2(PO4)3||Na solid-state sodium batteries deliver remarkably electrochemical stability. These results offer benign reference to the maturation of NASICON-based solid-state sodium batteries.

Here, with the state-of-the-state electron microscope, the authors report three-dimensional atomic-scale observation of LiNi0.5Mn1.5O4 from various directions, revealing unprecedented insight into the evolution of both atomic and electronic structures during delithiation.

Organic materials, especially the carbonyl compounds, are promising anode materials for room temperature sodium-ion batteries owing to their high reversible capacity, structural diversity as well as eco-friendly synthesis from bio-mass. Herein, we report a novel anthraquinone derivative, C14H6O4Na2 composited with carbon nanotube (C14H6O4Na2-CNT), used as an anode material for sodium-ion batteries in ether-based electrolyte. The C14H6O4Na2-CNT electrode delivers a reversible capacity of 173 mAh g−1 and an ultra-high initial Coulombic efficiency of 98% at the rate of 0.1 C. The capacity retention is 82% after 50 cycles at 0.2 C and a good rate capability is displayed at 2 C. Furthermore, the average Na insertion voltage of 1.27 V vs. Na+/Na makes it a unique and safety battery material, which would avoid Na plating and formation of solid electrolyte interface. Our contribution provides new insights for designing developed organic anode materials with high initial Coulombic efficiency and improved safety capability for sodium-ion batteries.

Discovering suitable electrodes is a challenge for the development of sodium-ion batteries. Here the authors demonstrate a high-performance symmetric battery based on Na2VTi(PO4)3, highlighting its potential application in a smart grid.

Ideal energy storage technologies should be efficient, safe and cost-effective. Here, the authors make progress by using dissolved sodium metal in a solution of biphenyl and ethers as a liquid anode for rechargeable sodium beta-alumina batteries.

Background: Most patients with epilepsy want to learn as much as possible about the disease, and many have turned to the internet for information. Patients are likely to use information obtained from the internet to control their epilepsy, but little is known about the accuracy of this information. In this survey, we have assessed the feasibility and usability of internet-based interventions for the treatment of epilepsy. Methods: Data were collected from an internet search. Different search terms were used to obtain general information on epilepsy together with information about medication, types of epilepsy, treatment, women′s health, and other information. The accuracy of the information was evaluated by a group of experts. Results: A total of 1320 web pages were assessed. The majority were websites related to health. A large number (80.2%) of web pages contained content related to the search term. A significant number of web pages 450/1058 (42.5%) claimed to provide information from a credible source; however, only 206/1058 (19.5%) of the information was accurate and complete; 326/1058 (30.8%) was accurate but incomplete; 328/1058 (31.0%) was correct but nonstandard, and 198/1058 (18.8%) was inaccurate. The authenticity of the information was not significantly different between the two search engines (χ2 = 0.009, P = 0.924). No significant difference was observed in the information obtained from a specialist or nonspecialist source (χ2 = 7.538, P = 0.057). There was also no correlation between the quality of the information and the priority (χ2 = 6.880, P = 0.076). Conclusions: Searching for information about epilepsy on the internet is convenient, but the information provided is not reliable. Too much information is inaccurate or for advertisement purposes, and it is difficult for patients to find the useful information. Turning to the internet for medical knowledge may be harmful. Physicians should be aware that their patients may search for information on the internet and guide them to safe, reputable websites.

In the title compound, {(C4H16N3)[La(SO4)3(H2O)]}n, the La atom adopts an irregular LaO9 coordination geometry, including one bonded water molecule. The three sulfate groups adopt both monodentate and bidentate coordination to the metal ions. Two of the sulfate groups serve as bridges in the (100) and (010) directions, yielding infinite sheets, whereas the third is pendant to one La3+ cation. The protonated organic species interacts with the layers by way of N—H...O hydrogen bonds, and O–H...O hydrogen bonds involving aqua ligands also occur.

In the hydro/solvothermally synthesized title compound, Na4[Cu2(H2Ge2O7)(H2GeO4)2]·H2O, the framework building units include CuO4, GeO2(OH)2 and GeO3(OH) tetrahedra, the latter being condensed into H2Ge2O74− dimers. All the tetrahedra are connected by corner-sharing into four-membered-ring (4MR) secondary building units containing two CuO4, one GeO2(OH)2 and one GeO3(OH) entity. The 4MRs form chains by corner-sharing the Cu unit and adjacent chains are linked by H2Ge2O74− dimers, generating layers containing ten-membered rings. Three sodium cations (one with site symmetry overline{1} and one with site symmetry 2) and a water molecule (O-atom site symmetry 2) complete the structure. A network of O—H...O hydrogen bonds helps to consolidate the packing.