Lithium (Li) metal is a highly promising anode for next-generation high-energy-density batteries. However, its practical application remains hindered by uncontrolled dendritic growth and severe Li/electrolyte side reactions. Here, we report a molecular precursor conversion strategy to a lithiophilic and mechanically robust solid electrolyte interphase (SEI) on Li metal. In this design, 2-acrylamido-2-methylpropanesulfonic (AMPS) acid is pre-anchored on the Li metal surface via the in situ reactions with the Li substrate and native surface species (Li2CO3, Li2O, LiOH, etc.), forming the AMPSLi layer. This interlayer subsequently acts as a molecular precursor for the SEI formation during battery cycling, promoting the generation of an organic-inorganic hybrid SEI enriched with Li2SO4, Li2SO3, and Li2S. These unique compositional characteristics of the SEI contribute to homogenised Li+ flux and accelerated Li+ transport, thereby enabling uniform Li deposition while simultaneously suppressing electrolyte decomposition. As a result, Li parallel to Li symmetric cells exhibit stable cycling for over 1000 h at 0.5 mA cm-2, and Cu parallel to Li half-cells deliver an average coulombic efficiency of 97% over 220 cycles. Full cells paired with LiFePO4 or LiNi0.8Co0.1Mn0.1O2 cathodes achieve similar to 75% capacity retention after 300 cycles in carbonate electrolytes. This work establishes molecular precursor conversion as an effective strategy for engineering stable SEIs toward practical Li metal batteries.

Abstract Anode-free aqueous zinc batteries offer high-energy, low-cost storage but suffer from dendritic Zn deposition, water-induced side reactions, and active Zn loss on bare current collectors. Here, we develop a hydrophobic hydrogen titanate nanosheet-modified Cu current collector (HTO@Cu) as a multifunctional Zn host. Ti-O/Ti-OH sites enhance Zn2+ affinity and homogenize nucleation, the interconnected nanosheet network regulates Zn growth, and the hydrophobic surface suppresses interfacial water accumulation and parasitic reactions. Experiments and calculations confirm faster interfacial Zn2+ transfer, more uniform Zn deposition, and reduced water-related side reactions. Zn||HTO@Cu cells achieve 1200 cycles with an average Coulombic efficiency of 99.58%, while symmetric cells operate for over 2500 h. Strictly anode-free HTO@Cu||NVO cells (N/P = 0) cycle for over 40 cycles, and limited-Zn cells (N/P = 3) deliver 305 mAh g–1. The pouch cell reaches 178.5 Wh kg–1 based on cathode active material.

Lithium-sulfur batteries (LSBs) face sluggish sulfur reduction reaction kinetics and severe polysulfide shuttling issues, which significantly limit their performance. In this work, a multifunctional separator with a 3D porous framework featuring confined pore structures and selective adsorption capability is constructed to address these challenges. Within this separator, Lewis acid-base interactions between Ce-MOF-808 and lignosulfonate (SL) effectively regulate the Ce4+ catalytic activity, thereby lowering the kinetic barrier and accelerating the conversion of short-chain polysulfides into insoluble Li2S during the liquid-solid transformation. Furthermore, SL prevents the accumulation of long-chain polysulfides near the Ce4+ sites through localized electrostatic repulsion, avoiding catalyst poisoning and thereby maintaining continuous catalytic availability. These synergistic effects collectively enable long-lasting catalytic activity toward polysulfide conversion in LSBs, resulting in a fivefold enhancement in capacity and an impressively low capacity decay rate of just 0.033% per cycle over 500 cycles at 1C. This work underscores the transformative potential of Lewis acid-base interactions for enhancing sulfur redox kinetics and introduces a versatile methodology for designing advanced separators for LSBs. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic),Ce-MOF-808(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)Ce4+(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)Li2S(sic)(sic)(sic).(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)Ce4+(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)1C(sic)(sic)(sic)(sic)(sic)500(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)0.033%.(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).

Sodium-ion batteries (SIBs) are a promising technology for advanced energy storage systems. Hard carbon (HC) is a commonly used SIB anode material; however, the Na ion storage mechanism in HC remains poorly understood and highly debated. Here, the paramagnetic species in HC during Na ion storage are systematically studied to elucidate the underlying mechanism at an electronic level using high-resolution electron paramagnetic resonance (EPR) spectroscopy, complemented by in situ Raman spectroscopy, in situ synchrotron X-ray diffraction, and density functional theory calculations. This investigation identifies and characterizes the coexistence of two distinct intercalation processes in HC: Na ion intercalation and Na+-solvent co-intercalation, which are active across both the sloping and plateau voltage regions. Additionally, in the sloping region, Na ions are also stored at in-plane Stone-Wales defect sites, which transition into a quasi-metallic state and subsequently to metallic Na as Na ion intercalation progresses. This transformation is driven by charge redistribution within the graphene layers. These insights establish a direct paramagnetic-electronic structure-electrochemical property relationship in HC, providing new insights into the Na ion storage mechanism. Furthermore, this study highlights the unique capability of EPR spectroscopy in elucidating the charge storage mechanism in electrode materials.

Cathode-electrolyte interphases (CEIs) are crucial for improving battery performance, yet conventional CEIs often show poor adhesion to cathodes, particularly those undergoing pronounced volume fluctuations. Here, we demonstrate the construction of a sulfur-containing CEI (S-CEI) on iron-based Prussian blue analog (FePB) cathodes for sodium-ion batteries via interfacial orbital hybridization between Fe 3d orbitals in FePB and O sp2 orbitals in 1-propene 1,3-sultone (PS). X-ray absorption near edge structure (XANES) spectroscopy combined with density functional theory (DFT) calculations reveals that this 3d-sp2 orbital hybridization redistributes local electron density, altering Fe coordination in FePB and the -SO3- environment in PS. This interaction triggers in situ formation of a uniform S-CEI rich in RSO3Na species on FePB during battery initial cycling. These RSO3Na species strongly coordinate surface Fe centers via the inherited 3d-sp2 coupling, thereby firmly anchoring the S-CEI and stabilizing the FePB lattice. Cryogenic TEM demonstrates that the S-CEI remains chemically and structurally intact after prolonged cycling. In situ synchrotron X-ray diffraction reveals that the FePB@S-CEI exhibits a markedly suppressed cubic-to-tetragonal phase transition, with the unit-cell volume shrinkage rate reduced from 18.5 to 5.7%/V. Consequently, the FePB@S-CEI achieves stable cycling with only 0.013% capacity loss per cycle over 1500 cycles at 1C, high rate capability up to 90C, and reliable performance across -20 to 60 °C. This study presents a general strategy for designing robust CEIs through interfacial orbital hybridization to enhance battery performance.

Replacing flammable liquid electrolytes with solid polymer electrolytes (SPEs) can dramatically improve battery safety. Here, we report the development of silica (SiO2)-centered crosslinking SPEs by chemically bonding SiO2 nanoparticles with the polymer matrix. This innovative design not only ensures the uniform dispersion of SiO2 nanoparticles throughout the polymer matrix but also builds a robust interface between the nanofillers and the polymer matrix, thereby enhancing Na+ ionic conductivity. Simultaneously, it leverages the abundant hydroxyl (OH) groups on SiO2 nanoparticles to interact with ClO4- anions through Lewis acid-base interactions and hydrogen bonding, promoting sodium salt dissociation. Theoretical calculations corroborate these interfacial mechanisms, revealing a 5.6-fold improvement in the Na+ diffusion coefficient. As a result, this pioneering design allows SPE to achieve a high Na+ ionic conductivity of 7.03 x 10-4 S cm-1 and an extended electrochemical voltage window up to 5.21 V. The assembled solid-state sodium metal batteries (with Na3V2(PO4)3 as the cathode) exhibit dendrite-free Na-metal deposition, promising rate capability, and stable cycling performance with 84.6 % capacity retention over 200 cycles at 0.2C and 64.1 % capacity retention over 200 cycles at 1C. This work introduces a transformative strategy of engineering nanofiller-polymer interactions to enhance the properties of SPEs for solid-state batteries.

Solid polymer electrolytes（SPEs） with high ionic conductivity are desirable for solid-state lithium metal batteries（SSLMBs） to achieve enhanced safety and energy density.Incorporating nanofillers into a polymeric matrix to develop nanocomposite solid electrolytes（NCSEs） has become a promising method for improving the ionic conductivity of the SPEs.Here,a novel ZIF-8-functionalized NCSE was prepared for high-temperature S SLMB s using an in situ radical polymerization method.It is found that the ZIF-8 nanoparticles could reduce the crystallinity of polymer segments and offer a Lewis acid surface that promotes the dissociation of lithium bis（trifluoromethanesulfonyl）imide（LiTFSI） and stabilizes the TFSI - anion movement.Thus,the as-prepared NCSE exhibits an outstanding ionic conductivity of 1.63 × 10 -3 S·cm -1 ,an electrochem ical stability window of 5.0 V at 80℃,and excellent interface compatibility with lithium metal anode with a stable polarization over 2000 h.Furthermore,the assembled SSLMBs with LiFePO 4 cathode show dendrite-free Li-metal surface,good rate capability,and stable cycling stability with a capacity retention of 70% over 1000 cycles at a high temperature of 80 ℃.This work provides valuable insights into promoting the ionic conductivity of SPEs.

Ni-based compounds represent promising candidates as high-performance electrocatalysts for the oxygen evolution reaction (OER) in alkaline media. Here, a new Ni oxide electrocatalyst developed via a simple electrodeposition method is reported, exhibiting enhanced catalytic activity for OER. Structural and activity analysis of the fresh and post-reaction samples reveals that the Ni2+ center has low coordination with pyramidal symmetry (NiO5). The bulk metallic Ni readily undergoes oxidation under OER conditions to generate more lowcoordinated Ni2+ and high-valence state Ni (Ni3+) species, thereby facilitating the OER reaction. This study provides new insight into the active structure of Ni-based oxide electrocatalysts and offers a simple pathway for the design and development of cost-effective and high-performance electrocatalysts for applications in OER.

Monolayer atomic crystals show significant advantages in improving charge storage kinetics for electrode materials. While notable progress is made, challenges remain in producing nanocrystals with desirable configurations, dimensions, and crystallographic properties. Here, 1D single-crystal nanobelts assembled from monolayer sodium titanate nanobelts are reported with highly exposed active sites as anode materials for sodium-ion batteries (SIBs). The unique structural properties of the 1D single-crystal nanobelts offer excellent electrochemical activity, electrochemo-mechanical stability, and well-maintained structural integrity, leading to highly efficient sodium ion storage performance. Insights into the electrochemical reaction processes, as revealed by in situ transmission electron microscopy, in situ synchrotron X-ray diffraction, and theoretical calculations, indicate that the 1D single-crystal nanobelts enable favorable sodium ion storage kinetics and a low-strain characteristic. This facilitates fast charge/discharge capability and long-term cycling stability for up to 5000 cycles at 20 C. Moreover, the 1D single-crystal nanobelts demonstrate practical applicability. A pouch cell assembled with the 1D single-crystal nanobelts anode and iron-based Prussian blue cathode exhibits highly stable cycling, achieving a low capacity fading ratio of approximate to 0.05% per cycle over 150 cycles. This study provides an innovative design principle to enhance the charge storage capability of electrode materials through intelligent structural nanoengineering. 1D single-crystal nanobelts, assembled from monolayer sodium titanate nanobelts featuring intensively exposed crystal planes, exhibit excellent electrochemical activity, robust electrochemo-mechanical stability, and favorable charge storage kinetics. As a result, these unique structural properties contribute to a low-strain characteristic during repeated sodium ion intercalation/de-intercalation, ensuring long-term cycling stability over 5000 cycles at 20 C. image

Nanoconfined polymer molecules exhibit profound transformations in their properties and behaviors. Here, we present the synthesis of a polymer-in-MOF single ion conducting solid polymer electrolyte, where polymer segments are partially confined within nanopores ZIF-8 particles through Lewis acid-base interactions for solid-state sodium-metal batteries (SSMBs). The unique nanoconfinement effectively weakens Na ion coordination with the anions, facilitating the Na ion dissociation from salt. Simultaneously, the well-defined nanopores within ZIF-8 particles provide oriented and ordered migration channels for Na migration. As a result, this pioneering design allows the solid polymer electrolyte to achieve a Na ion transference number of 0.87, Na ion conductivity of 4.01×10 −4  S cm −1 , and an extended electrochemical voltage window up to 4.89 V vs. Na/Na + . The assembled SSMBs (with Na 3 V 2 (PO 4 ) 3 as the cathode) exhibit dendrite-free Na-metal deposition, promising rate capability, and stable cycling performance with 96 % capacity retention over 300 cycles. This innovative polymer-in-MOF design offers a compelling strategy for advancing high-performance and safe solid-state metal battery technologies.

Alkali metal batteries have high energy densities required to power future devices; however, uneven metal deposition is a critical barrier to achieving long lifespans. We have developed an elegant noncryogenic transmission electron microscopy method which has facilitated the first observations of epitaxial deposition in alkali metal batteries. Using this method, we have confirmed epitaxial interactions between (002) sodium crystallite planes and (01-11) planes in zinc current collectors. Such epitaxial interactions decrease nucleation energy barriers and promote even metal growth. This study offers fresh inspiration for the development of electron microscopy techniques tailored to electron-sensitive battery materials and sets a new agenda for the development of battery technologies.

The irreversibility of anion intercalation-deintercalation is a fundamental issue in determining the cycling stability of a dual-ion battery (DIB). In this work, we demonstrate that using a partially fluorinated carbonate solvent can drive a beneficial fluorinated secondary interphase layer formation. Such layer facilitates reversible anion (de−)intercalation processes by impeding solvent molecule co-intercalation and the associated graphite exfoliation. The enhanced reversibility of anion transport contributes to the overall cycling stability for a Zn-graphite DIB—a high Coulombic efficiency of 98.5 % after 800 cycles, with an attractive discharge capacity of 156 mAh g −1 and a mid-point discharge voltage of ≈1.7 V (at 0.1 A g −1 ). In addition, the formed fluorinated secondary interphase suppresses the self-discharge behavior, preserving 29 times of the capacity retention rate compared to the battery with a commonly used carbonate solvent, after standing for 24 hours. This work provides a simple and effective strategy for addressing the critical challenges in graphite-based DIBs and contributes to fundamental understanding to help accelerate their practical application.

Lithium and sodium metal batteries continue to occupy the forefront of battery research. Their exceptionally high energy density and nominal voltages are highly attractive for cutting-edge energy storage applications. Anode-free metal batteries are also coming into the research spotlight offering improved safety and even higher energy densities than conventional metal batteries. However, uneven metal nucleation and growth which leads to dendrites continues to limit the commercialisation of conventional and anode-free metal batteries alike. This review connects models and theories from well-established fields in metallurgy and electrodeposition to both conventional and anode-free metal batteries. These highly applicable models and theories explain the driving forces of uneven metal growth and can inform future experiment design. Finally, the models and theories that are most relevant to each anode-related cell component are identified. Keeping these specific models and theories in mind will assist with rational design for these components.

Aqueous zinc-ion batteries have advantages over lithium-ion batteries, such as low cost, and good safety. However, their development is currently facing several challenges. One of the main critical challenges is their poor electrode-electrolyte interface. Addressing this requires understanding the physics and chem-istry at the electrode-electrolyte interface, including the cathode-electrolyte interface and anode -electrolyte interface. This review first identifies and analyses the interfacial challenges of aqueous zinc-ion batteries. Then, it discusses the design strategies for addressing the defined interfacial issues from the perspectives of electrolyte optimization, electrode modification, and separator improvement. Finally, it provides corrective recommendations and strategies for the rational design of electrode-elec-trolyte interface in aqueous zinc-ion batteries towards their high-performance and reliable energy storage.

Sodium metal batteries (NMBs) have attracted significant attention as next-generation, high energy density battery technologies. However, NMBs are disadvantaged by the excessive Na metal used as the anode, which decreases energy density and safety. So-called anode-free NMBs, where the anode is electrochemically generated during charging, are a promising solution. However, such batteries are still prone to dendrite growth and capacity fade. In this work, we computationally and experimentally screen a range of metals, including Zn, Cu, and alpha-brass, as current collectors for anode-free NMBs. Our results show that Zn was the best performing current collector material, inducing small nucleation overpotentials of -16.5 mV and increasing cycling stability up to 200 cycles with an average Coulombic efficiency of 98.9%. We propose this high performance is due to high lattice compatibility between Na and Zn as well as the formation of a favorable ZnF2-rich interphase. This study offers valuable insight into selecting current collectors and engineering the interfacial chemistry to improve the performance of anode-free NMBs.

Lithium-ion batteries (LIBs) have been dominating the battery market for decades. However, the rapidly increasing demand for LIBs has led to great concerns over lithium and cobalt resources. As a result, alternative rechargeable battery technologies have received great interests. Sodium-ion batteries (NIBs) that have a working principle similar to that of LIBs have proven to be a promising alternative to LIBs. This chapter summarises the recent development of organic liquid electrolytes in NIBs, including their designing principles, chemical compositions, the role of electrolytes in tuning cell performance, and the interfacial chemistry between electrolytes and electrode materials. In an NIB, the electrolyte is the Na-ion transport carrier between the cathode and anode separated by the separator. Electrochemical stability in a wide range of organic liquid electrolytes is an important factor for developing high-performance NIBs with high energy density, long lifetime, and safety.

The surface of battery electrodes has a tremendous influence on cell performance. Recent research progress towards surface structure engineering of anode materials for sodium-ion batteries is summarized and discussed in this article.

Phosphorus-rich metal phosphides have a high theoretical sodium-ion storage capacity. For example, cobalt disphosphide (CoP2) possesses a theoretical sodium-ion storage capacity of about 1330 mAh g(-1), while the theoretical capacity of cobalt phosphide (CoP) is about 893 mAh g(-1). However, it is currently challenging to synthesise phosphorus-rich metal phosphides. Herein, we report the synthesis of phosphorus-rich rod-like cobalt disphosphide with a carbon shell (CoP2@C) by thermal decomposition of polydopamine-coated cobalt oxalate in the presence of sodium hypophosphite. The as-obtained CoP2@C anode delivered a high sodium-ion storage capacity of similar to 550 mAh g(-1) at 500 mA g(-1) due to its multi pseudocapacitive and intercalation charge storage mechanisms. These preliminary results show that CoP2@C hold a great promise for developing high-performance electrochemical energy storage devices based on sodium-ion as the charge carrier.

Ion electrokinetic regulation in electrolyte is of great significance to alleviating polysulfide shuttling and dendritic growth in lithium-sulfur (Li-S) batteries. Inspired by the tunable solute-polymer interactions of ion exchange membrane, herein we implant an ion-selective "skin " constructed by isocyanoethyl methacrylate grafted polyethylenimine (PEI-IEM) in electrolyte via in situ gelation. This tailored skin endows the PEI-IEM-based gel polymer electrolyte (GPE) with a hyper-branched network with abundant polar groups, thus upgrading the electrolyte flame resistance, realizing obstruction on polysulfide migration, and facilitating Li+ transport against uneven deposition. Consequently, the PEI-IEM-based GPE empowers enhanced S electrochemical reversibility and high security, as evidenced by a 10 Ah Li-S pouch cell with a low electrolyte/S ratio of 2.6 and 1.43 excess Li anode that delivers an energy density of 412.7 Wh kg(-1). This proof-of-concept study provides new insights for tailoring the ionic behaviors of electrolyte to achieve high-energy and safe Li-S batteries.

The hybrid ion capacitor (HIC) is a hybrid electrochemical energy storage device that combines the intercalation mechanism of a lithium-ion battery anode with the double-layer mechanism of the cathode. Thus, an HIC combines the high energy density of batteries and the high power density of supercapacitors, thus bridging the gap between batteries and supercapacitors. Two-dimensional (2D) carbon materials (graphite, graphene, carbon nanosheets) are promising candidates for hybrid capacitors owing to their unique physical and chemical properties, including their enormous specific surface areas, abundance of active sites (surface and functional groups), and large interlayer spacing. So far, there has been no review focusing on the 2D carbon-based materials for the emerging post-lithium hybrid capacitors. This concept review considers the role of 2D carbon in hybrid capacitors and the recent progress in the application of 2D carbon materials for post-Li (Na+, K+, Zn2+) hybrid capacitors. Moreover, their challenges and trends in their future development are discussed.