With low melting points and viscosities, linear ether-based solvents effectively lower the Na+ desolvation energy barrier in low-temperature sodium metal batteries. Among them, 1,2-diethoxyethane (DEE) is considered a promising solvent due to its relatively weak solvating ability at low temperatures; however, its two oxygen atoms remain electronically isolated, forming quasi-chelating bidentate coordination structures with Na+ and still triggering a high desolvation energy barrier under extremely cold conditions. Herein, a novel electrolyte based on the concept of synergistic-competitive coordination is designed by introducing dimethoxymethane (DMM) as a cosolvent into the DEE-based electrolyte, where the lone-pair electrons on oxygen atoms in DMM are partially delocalized, thus reducing its electron-donating capability toward Na+ and reconstructing the Na+ solvation structure. Molecular dynamics simulations reveal that DMM competes with DEE for Na+ coordination sites, thereby weakening the Na+-DEE interaction, lowering the desolvation energy barrier, and promoting anion-involved coordination under severe cold conditions. Consequently, Na||Na symmetric cells run stably for over 3500 h at -40°C, while Na||Cu cells show 99.7% coulombic efficiency over 200 cycles at -20°C. Moreover, NaFe1/3Ni1/3Mn1/3O2||Na full cell retains 78.7% capacity after 200 cycles at -20°C, while Na3V2(PO4)3||Na full cell maintains an impressive 99.2% reversible capacity over 300 cycles at -40°C.

A schematic of NaHMDS as a sacrificial sodium source for highly reversible anode-free sodium batteries with stable SEI/CEI interphases and dendrite-free deposition.

Density functional theory (DFT) calculations were used to investigate the geometric structures, structural stability, bonding interactions, and charge transfer characteristics of W2Sn−(n = 1−12) clusters. The results reveal that with increasing sulfur content, the number of bridging S atoms grows progressively until a saturation limit of five bridging S ligands is reached, defining the core coordination shell. The cluster stability is governed by a competition between predominantly ionic W–S interactions, which are synergistically stabilized by both electrostatic attraction and orbital hybridization effects. Specifically, a δ-backdonation dominates the bonding in bridging S ligands, while a π-backdonation is characteristic of terminal S ligands. Unidirectional charge transfer from W to S atoms is identified. Crucially, it is demonstrated that bridging S atoms intrinsically weaken cluster stability, whereas terminal S atoms exhibit a dual role, capable of either stabilizing or destabilizing the cluster depending on their local coordination environment. This work provides comprehensive and systematic theoretical insights into ditungsten sulfide anionic clusters, offering a reliable atomic-level basis for the rational design of W–S functional nanomaterials.

Sodium-metal batteries (SMBs) are seen as a promising energy storage option due to their high energy density, abundant sodium resources, and cost-effectiveness. However, traditional organic liquid electrolytes (LEs) suffer from inherent safety risks, including leakage and flammability. Solid polymer electrolytes (SPEs) are regarded as a viable alternative to LEs for safer SMBs. However, the poor interfacial contact and insufficient ion transport associated with conventional ex situ prepared SPEs make it difficult for them to outperform LEs. The in situ polymerization technique, characterized by its process scalability and ability to form conformal interfaces, has proven effective in overcoming the obstacles associated with SPEs. In this review, we summarize recent research on in situ polymerization techniques for SMBs, including free-radical polymerization, ionic polymerization, electropolymerization, and related approaches. The importance of in situ polymerization in streamlining the preparation process, enhancing the compatibility of the electrode-electrolyte interface, bolstering battery safety, and optimizing electrochemical performance is highlighted. Furthermore, we systematically discuss the multiscale design principles of this technology, emphasizing precursor formulation, reaction kinetics, and targeted bulk-matrix properties. The advanced functional applications of in situ polymerization in SMBs, particularly in suppressing crosstalk effects, regulating solvation structures, and designing artificial interfacial layers and materials, are discussed. Finally, critical challenges, future prospects and pathways toward the practical, large-scale application of in situ polymerization are evaluated. This review aims to provide systematic insights to facilitate the rapid progress and implementation of in situ-polymerized electrolytes in SMBs.

To address weak fluid excitation, low energy conversion efficiency, and high starting flow velocities of conventional triboelectric nanogenerators (TENGs) in low-speed water flows, this work proposes a phase-shift constant-voltage triboelectric nanogenerator (PSCV-TENG) coupled with the intermittent speed-up mechanism (ISUM) and bionic jellyfish blades (BJB) for low-speed water-flow energy harvesting. The device employs a multiphase rotary-disk TENG as its core and uses phase superposition to produce a quasi-DC output with a low crest factor, thereby mitigating the large fluctuations and low downstream utilization efficiency of conventional AC TENGs. The ISUM, consisting of a spiral spring, stopper, sliding rail, and cam, accumulates energy under low-speed fluid input and releases it instantaneously. The high responsiveness of the BJB improves fluid capture, while transmission amplification lowers the starting flow velocity to 0.23 m s−1. At a flow velocity of 0.5 m s−1, the proposed device achieves 46.5 times the output performance of a conventional TENG, with a peak power of 7.33 mW and a crest factor as low as 1.07. In field river tests, it delivers an average output power of 1.2 mW at 0.6 m s−1. This work offers a new strategy for efficiently harvesting low-grade water-flow energy.

TFPA additive enables the formation of LiF/Li 3 PO 4 -rich SEI with high mechanical strength and fast Li⁺ transport on Li metal, which can keep stable Li plating at 5 mA cm −2 as well as superior electrochemical performances in high-voltage full batteries.

Emerging contaminants (ECs) in water are a prominent environmental concern worldwide. Despite advanced oxidation or reduction being appealing transformation approaches, existing technologies face challenges in adaptability to the removal of both electron-rich ECs and ECs with electron-withdrawing moieties. Here, a Janus electrocatalytic membrane was fabricated to induce hydroxyl radicals (•OH) and atomic hydrogen (H*) simultaneously and tune redox processes via sequential tactics to achieve adaptable and ultrafast removal of diverse ECs. The Janus electrocatalytic carbon-fiber membrane with single-atom (SA) Fe and Ni anchored on two different sides, respectively, exhibited an excellent performance in the degradation of various ECs and treatment of the secondary effluent of pharmaceutical wastewater. Model ECs like propranolol and chloramphenicol were 100% removed at a high water flux (680 L m-2 h-1) and low energy consumption (<0.015 kWh m-3 log-1). In the electrofiltration sequence of Side-Fe to -Ni, the •OH yield was enhanced due to the flow-enhanced mass transfer of Side-Fe-induced H2O2 to Side-Ni-induced H* and the subsequent reaction to form •OH, favoring electron-rich organic degradation. While in the opposite sequence, the process of H*-mediated reduction followed by •OH-mediated oxidation achieved thermodynamical superiority, favoring the degradation of ECs with electron-withdrawing groups. This study highlighted a new reversible membrane design enabling tunable redox for the removal of various ECs from wastewater.

Anode‐free sodium metal batteries (AFSMBs) are highly promising candidates for low‐cost, sustainable, and high‐energy‐density storage systems. However, their practical deployment is challenged by uncontrolled dendrite growth and unstable solid electrolyte interphase (SEI) formation. To address these issues, a highly reversible and robust Na metal host enabled by atomic Bi sites is devised, coordinated in a unique N 3 ‐Bi‐S 1 moiety anchored on interconnected carbon tubes (Bi‐N 3 S 1 @CT). Crucially, this designed remarkably sodiophilic Bi single‐atom promotes uniform Na nucleation with minimal Na + consumption, enabling durable and highly reversible Na plating/stripping, while effectively suppressing electrolyte over‐decomposition and fostering the formation of robust inorganic‐rich SEI films, as supported by comprehensive theoretical calculations and experimental analyses. Consequently, Bi‐N 3 S 1 @CT achieves an extraordinary average Coulombic efficiency (CE) of 99.6% over 900 cycles at 12 mA cm −2 and 6 mAh cm −2 , along with long‐term durability of 1000 h at 10 mA cm −2 and 10 mAh cm −2 in symmetric cells. Notably, an anode‐free pouch cell paired with a high‐loading Na 3 V 2 (PO 4 ) 3 cathode exhibits decent cyclability over 240 cycles at 1C while maintaining good rate capability. This work demonstrates a promising strategy to simultaneously enhance energy density and stability in AFSMBs via atomic‐level sodiophilicity regulation and SEI engineering.

NiFe based catalysts are expected to replace commercially available noble metal-based electrocatalysts for oxygen evolution reaction (OER) due to their reconfigurability into high performance NiFe oxyhydroxides from their phosphides. However,...

The commercialization of high-voltage lithium (Li) metal batteries (LMBs) has been severely hindered due to the lack of advanced electrolytes that can simultaneously support a stable lithium metal anode (LMA) and high-voltage cathode (>4 V vs Li+/Li). Here, we propose a tetrahydropyran (THP)-based weakly solvating electrolyte (WSE) to regulate Li+ solvation structures and interfacial behaviors. The anion-rich Li+ solvation in THP-based WSE effectively promotes the formation of inorganic-rich solid electrolyte interphase (SEI) layers, firm cathode electrolyte interphase (CEI) films, and protective passivation films on an Al current collector. The optimized interfacial behaviors contribute to the highly compact Li deposition, high-voltage stability, and inhibition of transition metal ion dissolution and Al corrosion. Finally, the Li||LiNi0.5Co0.2Mn0.3O2 full cell delivered stable cycling performance at high cutoff voltages of 4.3 and even 4.5 V. This study demonstrates an exciting approach to enable ether-based electrolytes for high-voltage LMBs and could be developed for other battery systems.

Polymer solid-state electrolyte (SSE) still confronts low room-temperature ionic conductivity for broad appli-cation in solid-state batteries. Herein, an eye-catching polymer-in-salt PVDF-HFP/LiFSI/LLZTO composite SSE with ultrahigh ionic conductivity is elaborately designed. In this electrolyte system, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix provides the electrolyte well mechanical property and Li salt solubi-lity, high content of lithium bis(fluorosulfonyl) imide (LiFSI) with low dissociation energy contributes to extra Li+ hopping transmission path, and Li6.4La3Zr1.4Ta0.6O12 (LLZTO) filler endows the SSE enhanced electro-chemical stability. As a consequence, this polymer-in-salt composite SSE exhibits an ionic conductivity of 1.67 x 10-3 S cm- 1 and superior critical current density (CCD) of 3.2 mA cm-2 at room temperature (25 degrees C). Moreover, Li||Li symmetric battery holds uniform polarization over 240 h at 0.3 mA cm-2 and 0.3 mAh cm-2. And Li|| LiFePO4 full cell exhibited a high capacity retention ratio of 97.2% with Coulombic efficiency of 99.75% after 300 cycles.

Polymer solid electrolytes (SEs) with high safety and flexibility are ideal for advanced lithium‐metal solid‐state batteries (SSBs). Among various polymer SEs, polyvinylidene fluoride ‐co ‐hexafluoropropylene (PVDF‐HFP) polymer SEs have gained increased attention for their high dielectric constants, high ionic conductivity, and excellent flexibility. However, severe side reactions at the interface caused by the decomposition of residual DMF solvent significantly reduce the cycle life of PVDF‐HFP‐based SSBs. Herein, La 2 O 3 nanoparticles are used as new inorganic fillers to form a PVDF‐HFP/LiFSI/La 2 O 3 ‐40% composite polymer electrolyte (PVDF‐HFP/La 2 O 3 CPE). Benefiting from the interaction between La 2 O 3 and N,N ‐dimethylformamide (DMF) solvent molecules, the cell cycling stability is greatly improved. In addition, the PVDF‐HFP/LiFSI solid electrolyte (PVDF‐HFP SE) containing 40 wt% La 2 O 3 has the highest ionic conductivity of 1.33 × 10 −3 S cm −1 at 25 °C. It also exhibits a higher lithium‐ion transference number of 0.52 and lower polarization. The PVDF‐HFP/La 2 O 3 CPE here ensures high ionic conductivity and stable interface chemistry in SSB, demonstrating a promising application potential.

High energy density lithium (Li) metal batteries (LMBs) hold great promise to become next-generation energy storage devices. However, their commercialization process is severely hindered by low Coulombic efficiency (CE) and potential safety hazard caused by non-uniform Li deposition and flammable electrolytes. Herein, a brand-new ultralow concentration (0.3 M) mixed ether electrolyte is proposed to regulate the electrolyte structure, flammability and solid electrolyte interphase (SEI) composition for LMBs. The high proportion of flame retarded inert solvent (94% by volume) remarkably improves the security of LMBs and promotes anions involving in Li+ solvent sheath structures. Therefore, differing from Li+-solvent dominant solvent sheaths in traditional low concentration electrolyte, the abundant Li+-anion aggregate cluster in this ULCE could lead to sufficient decomposition of anion and formation of inorganic-rich SEI. Based on this electrolyte design, the average Li deposition/stripping CE reaches > 99.3% under 2 mA cm(-2) and 1 mAh cm(-2) among 250 cycles. Moreover, superior electrochemical performance of Li||Li4Ti5O12 and Li||sulfur full cells also confirm the practical application value of this ULCE. This work proposes a fresh strategy to design low concentration electrolytes with unique solvated structures for high energy density metal batteries.

Garnet‐type solid‐state electrolytes (SEs) represented by Li 7 La 3 Zr 2 O 12 (LLZO) are considered ideal ion‐conducting materials for oxide all‐solid‐state lithium batteries (ASSLBs) due to their high ionic conductivity and wide electrochemical window. However, there are still many problems at the interface of the composite cathode side with LLZO‐based SEs as ion conductors as LLZO has poor interfacial contact with other particles and shows air instability when exposed to air because of the spontaneous reaction with water and CO 2 . Among them, the high impedance at the interface is a key issue that severely limits the actual energy density and cycle life of ASSLBs. With the optimized modification of LLZO‐based SEs and the in‐depth study of the interfacial mechanism, some breakthroughs have been made in the electrochemical performance of LLZO‐based ASSLBs. Hence, this review first describes the factors causing high interfacial impedance inside LLZO‐based composite cathode, such as poor interparticle contact, stress disruption and elemental diffusion at the interface, and discontinuous ion/electron percolation paths and then summarizes the solution strategies, for example, microstructure design, component optimization, and internal interface modification. Finally, the development prospect of LLZO‐based ASSLBs composite cathode is prospected to provide a useful reference for exploring the practical application of LLZO‐based ASSLBs.

The uncontrollable dendrite growth is the most critical barrier that hinders the practical applications of Li metal anodes. Herein, a novel lithiophilic and mixed ion/electron conductive current collector is constructed via a facile in-situ activation process of nickel sulfide on the Nickel foam (NF). Such current collector exhibits excellent lithiophilicity, high Li+ diffusion coefficient and electron conductivity due to its unique vertical-aligned and interconnected arrays consisting of lithium sulfide and nickel on NF skeleton. Especially, the mixed ion/electron conductive arrays not only effectively regulate the ionic flux and electric field, but also provide continuous pathways for the fast transportation of both the Li+ and electron. As a result, the growth of Li dendrites is suppressed. Moreover, full cells with low Negative/positive (N/P) ratio exhibit superior cycling stability, highcapacity retention and outstanding rate performance. Typically, full cells pairing with LiFePO4 (LFP) cathodes with a N/P ratio of 6.3 show long-term cycling for over 700 and 350 cycles at high rates of 5C and 10C, delivering ultrahigh capacity retentions of over 95.7% and 86.4%, respectively. Even with an ultralow N/P ratio of 1.2 with LFP loading of 2.45 mAh cm-2, the full cell still shows excellent cycling stability for over 130 cycles. This work sheds new light on the development of dendrite-free Li metal anodes for high-performance Li metal batteries with lithiophilic and ion/electron dual-regulated current collector.

The lithium metal anode (LMA) is regarded as a very promising candidate for next-generation lithium batteries. The interfacial issue plays a pivotal role in affecting the lithium plating/stripping behavior, Coulombic efficiency and cycling lifespan of an LMA. The lithium reduction reaction (LRR) is an advanced regulating technique for optimizing the LMA interphase, which intelligently utilizes lithium metal itself as an interphase precursor. This strategy also possesses moderate operating conditions, high efficiency, great convenience and scalability. In this review, the latest developments of LRRs in interfacial regulation for LMAs are summarized, focusing on the interfacial regulation mechanism and the construction of various inorganic/organic interfaces in lithium metal liquid/solid batteries. The target interface properties and corresponding influence factors during LRRs are investigated in detail. Besides this, the superiority and insufficiency of LRRs are discussed and possible directions for LRRs are presented. This review highlights in situ modification characteristics for anode interface regulation during the LRR and can be extended to other metal anodes such as sodium, potassium and zinc.

A lithiophilic Sn-Co nano-seed sealed in a nitrogen-doped carbon shell is designed to stabilize lithium metal anodes, in which lithiophilic alloys can regulate lithium deposition behavior and the hollow carbon shell is beneficial to prevent agglomeration. The modified lithium anode can be stable for 1350 h and 400 h under 1 mA cm-2 and 5 mA cm-2 in symmetric cells. The Sn-Co@C@Li||LiFePO4 full cell with a low N/P ratio of 2.12 shows a superior capacity retention of >98% over 250 cycles under 1C.

A nanodiamond modified separator that simultaneously features favorable electrolyte affinity, outstanding mechanical strength and thermal diffusion ability has been designed for use in the development of highly stable and safe lithium metal batteries.