Sodium-ion batteries (NIBs) have become an ideal alternative to lithium-ion batteries in the field of electrochemical energy storage due to their abundant raw materials and cost-effectiveness. With the progress of human society, the requirements for energy storage systems in extreme environments, such as deep-sea exploration, aerospace missions, and tunnel operations, have become more stringent. The comprehensive performance of NIBs at low temperatures (LTs) has also become an important consideration. Under LT conditions, challenges such as increased viscosity of electrolyte, abnormal growth of solid electrolyte interface, and poor contact between collector and electrode materials emerge. The aforementioned issues hinder the diffusion kinetics of sodium ions (Na⁺) at the electrode/electrolyte interface and cause rapid degradation of battery performance. Consequently, the optimization of electrolyte composition and cathode/anode materials becomes an effective approach to improve LT performance. This review discusses the conduction behavior and limiting factors of Na⁺ in both solid electrodes and liquid electrolytes at LT. Furthermore, it systematically reviews the recent research progress of LT NIBs from three aspects: cathode materials, anode materials, and electrolyte components. This review aims to provide a valuable reference for developing high-performance LT NIBs.

Efficient electrocatalysis at the cathode is crucial to addressing the limited stability and low rate capability of Li–O₂ batteries. This study examines the kinetic behavior of Li–O₂ batteries utilizing layered perovskite LaSrCrO₄ nanowires (NWs) composed of lower oxidation states. Layered perovskite LaSrCrO₄ NWs exhibited improved rate capability over a wide range of current densities and longer cycle life in Li–O₂ batteries than V-based layered perovskite (LaSrVO₄) and simple perovskite (La_0.8Sr_0.2CrO₃) NWs. X-ray photoelectron spectroscopy and electrochemical surface area analyses showed that the observed performance variations primarily stemmed from active sites such as oxygen vacancies. In situ Raman analysis showed that these active sites significantly modulate the kinetics of oxygen reduction and evolution, which are related to LiO₂ intermediate adsorption. Electrochemical impedance spectroscopy showed that the active sites in layered perovskite LaSrCrO₄ NWs contributed to their high charge transfer capability and reduced polarization. This study presents an appealing method for the precise fabrication and analysis of Cr-based layered perovskites, aimed at achieving highly efficient and stable bifunctional oxygen electrocatalysis.

Though plenty of research has been conducted to improve the low intrinsic electronic conductivity of NASICON-structured NaTi₂(PO₄)₃ (NTP), realizing sodium-ion batteries with high areal/volumetric capacity still remains a formidable challenge. Herein, a multiscale design from anode material to electrode structure is proposed to obtain a gadolinium-ion-doped and carbon-coated NTP composite electrode (NTP-Gd-C), in which gadolinium ion doping, oxygen vacancy, optimized structure, N-doped carbon coating, and bridging on the three-dimensional network are simultaneously achieved. In the whole electrode, the excellent hierarchical electronic/ionic conductivity and structural stability are simultaneously improved via the synergistic optimization of NTP-Gd-C. As a result, excellent electrochemical performances of NTP-Gd-C electrode with a high areal/volumetric capacity of 1.0 mAh cm^–2/142.8 mAh cm^–3, high rate capability (58.3 mAh g^–1 at 200 C), long cycle life (ultralow capacity fading of 0.004% per cycle under 10,000 cycles), and wide-temperature electrochemical performances (97.0 mAh g^–1 at 2 C under –20°C) are achieved. Moreover, the NTP-Gd-C//Na₃V₂(PO₄)₃/C full cell also delivers an excellent rate capacity of 42.0 mAh g^–1 at 200 C and long-term high-capacity retention of 66.2% after 4000 cycles at 20 C.

Developing high-capacity and high-rate anodes is significant to engineering sodium-ion batteries with high energy density and high power density. Layered Na₂Ti₃O₇ (NTO), with an open crystal structure, large theoretical capacity, and low working potential, is recognized as one of the prospective anodes for sodium storage. Nevertheless, it suffers from sluggish sodiation kinetics and low (micro)structure stability triggered by a high Na⁺ diffusion barrier and weak adhesion of [Ti₃O₇] slabs. Herein, the interlayered local structure of NTO is regulated to solve the above issues, in which parts of interlayered Na⁺ sites are substituted by H⁺ (Na_2–xH_xTi₃O₇ [NHTO]). Theoretical calculations prove that the NHTO offers lower activation energy for Na⁺ transports and low interlayer spacings with alleviated Na–Na repulsion and relatively flexible [Ti₃O₇] slabs to reduce fractural stress. In situ and ex situ characterizations of (micro)structure evolution reveal that NHTO goes through transformation between H-rich and Na-rich phases, resulting in high structure stability and microstructure integrity. The optimal NHTO anode delivers a high capacity of 190.6 mA h g^–1 at 0.5 C after 300 cycles and a superior high-rate stability of 90.6 mA h g^–1 at 50 C over 10,000 cycles at room temperature. Besides, it offers a capacity of 50.3 mA h g^–1 after 1800 cycles at a low temperature of –20°C and 195.7 mA h g^–1 after 500 cycles at a high temperature of 40°C at 0.5 C. The developed topologically interlayered local structure regulation strategy would raise the prospect of designing high-performance layered anodes.

Lithium–gas batteries (LGBs) have garnered significant attention due to their impressive high-energy densities and unique gas conversion capability. Nevertheless, the practical application of LGBs faces substantial challenges, including sluggish gas conversion kinetics inducing in low-rate performance and high overpotential, along with limited electrochemical reversibility leading to poor cycle life. The imperative task is to develop gas electrodes with remarkable catalytic activity, abundant active sites, and exceptional electrochemical stability. Electrospinning, a versatile and well-established technique for fabricating fibrous nanomaterials, has been extensively explored in LGB applications. In this work, we emphasize the critical structure–property for ideal gas electrodes and summarize the advancement of employing electrospun nanofibers (NFs) for performance enhancement in LGBs. Beyond elucidating the fundamental principles of LGBs and the electrospinning technique, we focus on the systematic design of electrospun NF-based gas electrodes regarding optimal structural fabrication, catalyst handling and activation, and catalytic site optimization, as well as considerations for large-scale implementation. The demonstrated principles and regulations for electrode design are expected to inspire broad applications in catalyst-based energy applications.

As the cyclable sodium ions’ primary suppliers, O3-type layer-structured manganese-based oxides are recognized as one of the most competitive cathode candidates for sodium-ion batteries. Suffering from complex structural transformations and transition metal migration during the sodium intercalation/deintercalation process, particularly at high voltage, the energy density and lifespan cannot satisfy the increasing demand. The orbital and electronic structure of the octahedral center metal element plays an important role in maintaining the octahedral structural integrity and improving the Na⁺ diffusivity by the introduced heterogeneous [Me–O] (Me: transition metals) chemical bonding. Herein, inspired by the 4f and 5d orbital bonding possibility from the abundant configuration of extranuclear electrons and large ion radius, O3-type Na[La_0.01Ni_0.3Mn_0.54Cu_0.1Ti_0.05]O₂ was synthesized with a nearly single crystal structure. Based on the experimental and computational results, the introduced heterogeneous [La–O] chemical bond with larger bond strength can not only ensure the stability of the lattice oxygen framework and the reversibility of oxygen redox but also optimize the oxygen local electronic structure resulting from La 5d and O 2p orbital mixing due to O 2p → La 5d charge transfer. It delivers an optimal electrochemical performance with a high energy density and cycling lifespan.

Electrocatalysis has received a great deal of interest in recent decades as a possible energy-conversion technology involving a variety of chemical processes. External magnetic field application is a powerful method for improving electrocatalytic performance that is customizable and compatible with existing electrocatalytic devices. In addition, magnetic fields can assist in catalyst synthesis and act on the catalytic reaction process. This paper systematically reviews the most recent developments in magnetic field-assisted electrocatalytic enhancement technology. The enhancement of electrocatalysis by a magnetic field is mainly represented in the three features listed below: The spin selectivity effect improves the activity of the catalyst in a magnetic field; furthermore, magnetic fields can improve mass transport and electron transport in catalytic processes (due to Lorentz forces, Kelvin forces, magnetohydrodynamic [MHD], and micro-MHD); the magnetothermal effect may raise the reaction temperature and boost electrocatalytic activity. This review focuses on the rational design of catalytic systems incorporating the interaction between catalysts and magnetic fields, aiming to produce enhanced catalytic effects. The recommendations for further utilization of strategies for electrocatalysis and broader energy technologies for magnetic fields, as well as potential challenges for future research, are also discussed.

Embedding a third and/or fourth component into a binary blend active layer of organic photovoltaics (OPVs) is a promising approach to achieve high-performance photovoltaic cells and modules. This multicomponent strategy favors absorption broadening via additional components. Quaternary OPV (QOPV) blends have four components in three possible configurations: (i) a donor and three acceptors, (ii) two donors and two acceptors, or (iii) three donors and an acceptor. Although quaternary systems have only been relatively recently studied compared to other systems in OPVs, leveraging the synergistic effects of the four components leads to record power conversion efficiencies, currently approaching 20%. QOPVs provide ample material choices for compatibility and channels for charge transfer mechanisms, possibly leading to optimized morphology and orientation. Reviewing recent progress in advancing QOPVs is essential for understanding their contribution to the OPV field. The review mainly discusses research progress in QOPVs with a keen interest in their various configurations, semitransparency, and outdoor and indoor applications. It describes the not-well-understood QOPV’s general working mechanism. This review explores high-performance QOPVs based on the fourth component’s contribution as a donor, acceptor, or dye molecule and beyond in photovoltaic applications. Finally, there is a discussion around QOPV’s outlook and projected future research directions in this field. This review intends to provide an overview of the quaternary systems approach to OPVs and inform current and future researchers on investigating the full spectrum of OPVs.

The low-energy electrochemical production of hydrogen peroxide (H₂O₂) has garnered significant attention as a viable alternative to traditional industrial routes, with the goal of achieving carbon neutrality. For their H₂O₂ selectivity in the two-electron oxygen reduction reaction (ORR), the coordination environment of tungsten (W)-based materials is critical. In this study, atomically dispersed W single atoms were immobilized on N-doped carbon substrates by a facile pyrolysis method to obtain a W single-atom catalyst (W-SAC). The coordination environment of an isolated W single atom with a tetra-coordinated porphyrin-like structure in W-SAC was determined by X-ray photoelectron spectroscopy and X-ray absorption spectroscopy analysis. Notably, the as-prepared W-SAC showed superior two-electron ORR activity in 0.1 M KOH solution, including high onset potential (0.89 V), high H₂O₂ selectivity (82.5%), and excellent stability. By using differential phase contrast-scanning transmission electron microscopy and density functional theory calculations, it is revealed that the charge symmetry-breaking of W atoms changes the adsorption behavior of the intermediates, leading to enhanced reactivity and selectivity for two-electron ORR. This work broadens the avenue for understanding the charge transfer of W-based electrocatalytic materials and the in-depth reaction mechanism of SACs in two-electron ORR.

The restacking and oxidizable nature of vanadium-based carbon/nitride (V₂C-MXene) poses a significant challenge. Herein, tellurium (Te)-doped V₂C/V₂O₃ electrocatalyst is constructed via mild H₂O₂ oxidation and calcination treatments. Especially, this work rationally exploits the inherent easy oxidation characteristic associated with MXene to alter the interfacial information, thereby obtaining stable self-generated vanadium-based heterointerfaces. Meanwhile, the microetching effect of H₂O₂ creates numerous pores to address the restacking issues. Besides, Te element doping settles the issue of awkward levels of absorption/desorption ability of intermediates. The electrocatalyst obtains an unparalleled hydrogen evolution reaction and oxygen evolution reaction with the overpotential of 83.5 and 279.8 mV at –10 and 10 mA cm^–2, respectively. In addition, the overall water-splitting device demonstrates a low cell voltage of 1.41 V to obtain 10 mA cm^–2. Overall, the inherent drawbacks of MXene can be turned into benefits based on the planning strategy to create these electrocatalysts with desirable reaction kinetics.

The threat to information security from electromagnetic pollution has sparked widespread interest in the development of microwave absorption materials (MAMs). Although considerable progress has been made in high-performance MAMs, little attention was paid to their absorption frequency regulation to respond to variable input frequencies and their stability and durability to cope with complex environments. Here, a highly compressible polyimide-packaging carbon nanocoils/carbon foam (PI@CNCs/CF) fabricated by a facile vacuum impregnation method is reported to be used as a dynamically frequency-tunable and environmentally stable microwave absorber. PI@CNCs/CF exhibits good structural stability and mechanical properties, which allows precise absorption frequency tuning by simply changing its compression ratio. For the first time, the tunable effective absorption bandwidth can cover the whole test frequency band (2–18 GHz) with the broadest effective absorption bandwidth of 10.8 GHz and the minimum reflection loss of –60.5 dB. Moreover, PI@CNCs/CF possesses excellent heat insulation, infrared stealth, self-cleaning, flame retardant, and acid-alkali corrosion resistance, which endows it high reliability even under various harsh environments and repeated compression testing. The frequency-tunable mechanism is elucidated by combining experiment and simulation results, possibly guiding in designing dynamically frequency-tunable MAMs with good environmental stability in the future.

Enhancing the ionic conductivity of sulfide solid electrolytes (SEs) through dual-doping is a well-established approach, yet the atomic-level mechanisms driving these improvements remain elusive. By dual-doping Ge and Cl into the Li₁₀GeP₂S₁₂ (LGPS) framework, we synthesized Ge/Cl-doped LGPS (Li_10+xGe_1+2xP_2–2xS_12–xCl_x, x = 0.3) with an ionic conductivity of 12.4 mS/cm at 25°C, a value that stands among the highest for LGPS-type SEs. This achievement emphasizes the pivotal role of dopant selection in modulating Li-ion transport mechanisms, thereby enhancing SE performance. Our research elucidates the intricate atomic mechanisms responsible for this enhanced ionic conductivity, with a particular focus on the synergistic effects of Ge and Cl dual-doping. Integrating advanced multianalytical techniques, including experiments and atomistic modeling (machine-learning-assisted molecular dynamics simulations and density functional theory calculations), we provide comprehensive insights into the structure–property relationship in Ge/Cl-doped LGPS SEs. Our findings reveal that Cl doping significantly enhances the paddle-wheel dynamics, while Ge doping promotes cooperative Li diffusion through the formation of Li interstitials. This dual-doping approach not only elucidates the structural and functional dynamics of SEs but also paves the way for designing dopants to enhance ionic conductivity. The insights gained from this study offer a strategic direction for developing higher-performance SEs, highlighting the importance of tailored dopant selection in advancing energy storage technologies.

Ternary halo-sulfur bismuth compound Bi₁₉X₃S₂₇ (X = Cl, Br, I) with distinct electronic structure and full-spectrum light-harvesting properties show great application potential in the CO₂ photoreduction field. However, the relationship between photocatalytic CO₂ reduction performance and the function of halogens in Bi₁₉X₃S₂₇ is still poorly understood. Herein, a series of Bi₁₉X₃S₂₇ nanorod photocatalysts with intrinsic X and S dual vacancies were developed, which showed significant near-infrared (NIR) light responses. The types and concentrations of intrinsic vacancies were confirmed and quantified by positron annihilation spectrometry and electron spin resonance spectroscopy. Experimental results showed that Br atoms and intrinsic vacancies (dual Br-S) in Bi₁₉Br₃S₂₇ could greatly enhance the internal polarized electric field and improve the transfer and separation of photogenerated carriers compared with Bi₁₉Cl₃S₂₇ and Bi₁₉I₃S₂₇. Theoretical calculations revealed that Br atoms in Bi₁₉Br₃S₂₇ could facilitate CO₂ adsorption and activation and decrease the formation energy of reactive hydrogen. Among Bi₁₉X₃S₂₇ nanorods, Bi₁₉Br₃S₂₇ nanorods revealed the highest CO₂ photoreduction activity with CO yield rate of 28.68 and 2.28 µmol g_catalyst^–1 h^–1 with full-spectrum and NIR lights, respectively. This work presents an atomic understanding of the intrinsic vacancies and halogen-mediated CO₂ photoreduction mechanism.

The typical metal chloride-graphite intercalation compounds (MC-GICs) inherit intercalation capacity, high charge conductivity, and high tap density from graphite, and these are considered as one of the promising alternatives of graphite anode in rechargeable metal-ion batteries (MIBs). Notably, the special interlayer decoupling effects and the introduction of extra conversion capacity by metal chloride could greatly break the capacity limitation of graphite anodes and achieve higher energy density in MIBs. The optimization of both graphite host and metal chloride species with specific structures endows MC-GICs with design feasibility for different application requirements of different MIBs, such as several times the actual capacity compared to graphite anodes, rapid migration of large carriers, and other properties. Herein, a brief review has been provided with the latest understanding of conductivity characteristics and energy storage mechanisms of MC-GICs and their interesting performance features of full potential application in rechargeable MIBs. Based on the existing research of MC-GICs, necessary improvements and prospects in the near future have been put forward.

High-voltage LiCoO₂ (LCO) can deliver a high capacity and therefore significantly boost the energy density of Li-ion batteries (LIBs). However, its cyclability is still a major problem in terms of commercial applications. Herein, we propose a simple but effective method to greatly improve the high-voltage cyclability of an LCO cathode by constructing a surface LiF modification layer via pyrolysis of the lithiated polyvinylidene fluoride (Li-PVDF) coating under air atmosphere. Benefitting from the good film-forming and strong adhesion ability of Li-PVDF, the thus-obtained LiF layer is uniform, dense, and conformal; therefore, it is capable of acting as a barrier layer to effectively protect the LCO surface from direct exposure to the electrolyte, thus suppressing the interfacial side reactions and surface structure deterioration. Consequently, the high-voltage stability of the LCO electrode is significantly enhanced. Under a high charge cutoff voltage of 4.6 V, the LiF-modified LCO (LiF@LCO) cathode demonstrates a high capacity of 201 mA h g^–1 at 0.1 C and a stable cycling performance at 0.5 C with 80.5% capacity retention after 700 cycles, outperforming the vast majority of high-voltage LCO cathodes reported so far.

The commercial utilization of Zn metal anodes with high plating capacity is significantly hindered by the uncontrolled growth of dendrites and associated side reactions. Herein, a robust artificial ion-sieving MXene flake (MXF)-coating layer, with abundant polar terminated groups, is constructed to regulate the interfacial Zn²⁺ deposition behavior. In particular, the fragmented MXF coupled with in situ generated quantum dots not only has strong Zn affinity to homogenize electric fields but also generates numerous zincophilic sites to reduce nucleation energy, thus securing a uniform dendrite-free surface. Additionally, the porous coating layer with polar groups allows the downward diffusion of Zn²⁺ to achieve bottom-up deposition and repels the excessive free water and anions to prevent parasitic reactions. The ion-sieving effect of MXF is firmly verified in symmetric cells with high areal capacity of 10–40 mAh cm^–2 (1.0 mA cm^–2) and depth of discharge of 15%–60%. Therefore, the functional MXF-coated anode manifests long-term cycling with 2700 h of stable plating/stripping in Zn||Zn cell. Such rational design of MXF protective layer breaks new ground in developing high plating capacity zinc anodes for practical applications.

Aqueous zinc-based batteries are emerging as highly promising alternatives to commercially successful lithium-ion batteries, particularly for large-scale energy storage in power stations. Phosphate cathodes have garnered significant research interest owing to their adjustable operation potential, electrochemical stability, high theoretical capacity, and environmental robustness. However, their application is impeded by various challenges, and research progress is hindered by unclear mechanisms. In this review, the various categories of phosphate materials as zinc-based battery cathodes are first summarized according to their structure and their corresponding electrochemical performance. Then, the current advances to reveal the Zn²⁺ storage mechanisms in phosphate cathodes by using advanced characterization techniques are discussed. Finally, some critical perspectives on the characterization techniques used in zinc-based batteries and the application potential of phosphates are provided. This review aims to guide researchers toward advanced characterization technologies that can address key challenges, thereby accelerating the practical application of phosphate cathodes in zinc-based batteries for large-scale energy storage.

Solid-state sodium batteries (SSSBs) are poised to replace lithium-ion batteries as viable alternatives for energy storage systems owing to their high safety and reliability, abundance of raw material, and low costs. However, as the core constituent of SSSBs, solid-state electrolytes (SSEs) with low ionic conductivities at room temperature (RT) and unstable interfaces with electrodes hinder the development of SSSBs. Recently, composite SSEs (CSSEs), which inherit the desirable properties of two phases, high RT ionic conductivity, and high interfacial stability, have emerged as viable alternatives; however, their governing mechanism remains unclear. In this review, we summarize the recent research progress of CSSEs, classified into inorganic–inorganic, polymer–polymer, and inorganic–polymer types, and discuss their structure–property relationship in detail. Moreover, the CSSE–electrode interface issues and effective strategies to promote intimate and stable interfaces are summarized. Finally, the trends in the design of CSSEs and CSSE–electrode interfaces are presented, along with the future development prospects of high-performance SSSBs.

Designing integrated overall water-splitting catalysts that maintain high efficiency and stability under various conditions is an important trend for future development, yet it remains a significant challenge. Herein, novel nanoflower-like tri-metallic Ni–Ru–Mo phosphide catalyst ((Ni–Ru–Mo)P@F-CDs), integrated with F-doped carbon dots (F-CDs), were synthesized via a straightforward hydrothermal process and subsequent phosphatization. Attributable to precise interface engineering and electronic structure optimization, (Ni–Ru–Mo)P@F-CDs exhibit exceptional bi-functional catalytic activity in alkaline conditions, achieving remarkably low overpotentials of 231 and 123 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively, at a current density of 100 mA cm^–2. Industrially, only 1.426 V is needed for the same efficacy. Additionally, the catalyst requires merely 1.508 and 1.564 V for overall water splitting in 1 M KOH and simulated seawater, respectively, at 100 mA cm^–2. The catalyst also shows excellent stability, with minimal performance decline over 100 h within 100–200 mA cm^–2. Density functional theory calculations indicate that the interface structure synergistically optimizes Gibbs free energy for H* and O* intermediates during HER and OER, respectively, accelerating electrochemical water-splitting kinetics.