Metal Anode Research Articles

In the pursuit of the development of safe energy storage devices, aqueous zinc metal batteries have garnered incredible attention due to their non-flammable nature and high energy densities. However, they suffer from severe complicated degradations induced by dendrite formation, hydrogen evolution reaction, transition metal dissolution, and their crosstalk effect. Herein, membranes are designed and engineered for high mechanical strength, Zn2+ selectivity, and hydrophobicity to simultaneously address the complex degradations. The prevention of dendrite formation and crosstalk-induced side reactions results in high reversibility of Zn metal anodes with a high average CE of 99.73% and an excellent cycle life in full cells with a capacity retention of 88.87% after 1000 cycles. This result highlights the importance of crosstalk prevention in the separator and offers the design principle of novel membranes for aqueous Zn metal batteries, advancing toward commercial level without requiring major modifications to the overall system.

Lithium metal batteries (LMBs) have attracted extensive attention, owing to their high energy density. However, commercial carboxylate ester-based electrolytes exhibit inadequate oxidation stability and poor compatibility with lithium metal anodes, which restrict the performance of LMBs under high-voltage and wide-temperature conditions. In this work, a dual-reinforced Li+ solvation structure is proposed, consisting of 2-ethoxyethyl acetate and sulfolane with lithium hexafluorophosphate and lithium nitrate. The weak solvation capability and low freezing point of 2-ethoxyethyl acetate contribute to a substantial reduction in the Li+ desolvation energy. Meanwhile, the lithium nitrate is employed to construct a high durable inorganic-rich solid-electrolyte interphase (SEI) with low impedance. As a result, LMBs comprising a high voltage LiCoO2 cathode and the optimized electrolyte achieve an excellent capacity retention of 93.3% after 50 cycles at 0.1 C, 4.5 V, and 50 °C. In addition, the electrochemical performance at low-temperature is significantly improved, demonstrating 62.5% capacity retention after 90 cycles at 0.1 C, 4.5 V, and -60 °C. This work presents an approach for the development of electrolytes for high-voltage and wide-temperature LMBs.

Water-induced corrosion and zinc dendrite formation seriously disrupt the Zn plating/stripping process at the anode/electrolyte interface, which results in the instability of the Zn metal anode in aqueous zinc-ion batteries. To address the issues of the zinc metal anode, three water-soluble polymers with different hydrophilic groups—polyacrylic acid (PAA), polyacrylamide (PAM), and polyethylene glycol (PEG)—were designed as electrolyte additives in ZnSO4 electrolytes. Among them, the PAA-based system exhibited an optimal electrochemical performance, achieving a stable cycling for more than 360 h at a current density of 5 mA cm−2 with an areal capacity of 2 mA h cm−2. This improvement could be attributed to its carboxyl groups, which effectively suppresses zinc dendrite growth, electrode corrosion, and side reactions, thereby enhancing the cycling performance of zinc-ion batteries. This work provides a reference for the optimization of zinc anodes in aqueous zinc-ion batteries.

Lithium metal anodes are considered indispensable for next‐generation high‐energy batteries, but their practical application is severely hampered by interfacial instabilities that lead to uncontrolled dendrite growth and continuous electrolyte consumption. This review systematically addresses these challenges by evaluating state‐of‐the‐art electrolyte engineering strategies for both liquid and solid‐state systems. In liquid electrolytes, key approaches are analyzed, including high‐concentration/localized formulations, fluorinated components, and functional additives designed to form robust and stable solid electrolyte interphases. For solid‐state electrolytes, advances in polymer, inorganic, and composite systems are surveyed, aimed at enhancing ionic conductivity while mechanically suppressing dendrites. Finally,a forward‐looking perspective is proposed, highlighting that the integration of multiscale simulation, machine learning, and data‐driven screening will be key to the rational design and rapid discovery of advanced electrolytes. This integrated approach is expected to overcome a critical bottleneck, paving the way for the realization of safe and high‐performance lithium metal batteries.

Abstract Dry‐processed ultra‐thick cathodes can boost energy density through process innovation alone, but face key challenges from nonuniform additive/binder dispersion and increased ion‐transport resistance with thickness. In this study, a reduced graphene oxide (rGO)‐based nanocomposite in which polytetrafluoroethylene (PTFE) nanoparticles are anchored onto rGO surfaces is introduced. This PTFE anchoring effectively prevents graphene restacking and enables uniform dispersion throughout the electrode during the solvent‐free fabrication process via in situ nanofibrillation of PTFE. By employing this rGO@PTFE nanocomposite as a dual‐functional conductive and binding material, we successfully fabricated a high‐energy cathode based on high‐nickel layered oxide (NCM), achieving a significantly high areal and volumetric capacity of 15.2 mA h cm −2 and 562.9 mA h cm −3 , respectively. The incorporation of rGO@PTFE led to improved electrolyte wettability and uptake, as well as enhanced electronic conductivity. More importantly, it raised the lithium‐ion transference number to 0.73 and reduced the charge transfer resistance by 62% compared to a conventional reference electrode. Based on these advantages, the rGO@PTFE‐based thick cathode (G@P_TC), when paired with a lithium metal anode, enabled the development of a lithium metal battery with an unprecedented high volumetric energy density of 1088 Wh L −1 , while maintaining nearly 92% capacity retention over 50 cycles.

Abstract Realizing durable, uniform, and dendrite‐free sodium metal deposition is crucial for preventing premature battery failure caused by internal short circuits, which is primarily governed by ion transport and desolvation kinetics during the electrodeposition process. Herein, a composite quasi‐solid polymer electrolyte (LPQSE) is developed through in situ polymerization of poly(ethylene glycol) diacrylate within a porous membrane constructed by in‐house synthesized α‐LiAlO 2 @γ‐Al 2 O 3 (LAO) nanosheets and poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVHF). The LAO nanosheets effectively immobilize PF 6 − anions via Lewis acidic sites, while the PEGDA carbonyl groups coordinate Na⁺ cations. This dual‐interaction mechanism simultaneously reduces ion‐pair formation and promotes loose solvation structures, thereby accelerating desolvation kinetics and significantly increasing sodium nucleation density. Consequently, homogeneous sodium deposition with fundamentally suppressed dendrite nucleation is realized. As a result, solid‐state Na||Na symmetric cells demonstrate exceptional cycling stability, and Na 3 V 2 (PO 4 ) 3 (NVP)||Na batteries employing the ∼16‐µm‐thick LPQSE exhibit long‐term cycling stability. Notably, the NVP||Na battery exhibits a high specific discharge capacity of 69.5 mAh g −1 at 10 C and retains 88.7% capacity retention over 1000 cycles at 1C. This work establishes an innovative electrolyte design strategy that strategically coordinates anion immobilization and cation solvation to regulate deposition behavior for achieving dendrite‐free sodium anodes.

Abstract Compared with conventional solid polymer electrolytes (SPEs), polyester‐based quasi‐solid‐state electrolytes exhibit a wider electrochemical window and higher ionic conductivity but suffer from poor interfacial compatibility with lithium metal anodes. Here, an anion‐trapping strategy is described to design polyester‐based copolymer electrolytes (PECEs) with moderate Li⁺‐polyester (PVPT) interactions via molecular engineering of the polymer backbone, achieving excellent interfacial stability and electrochemical performance. In particular, incorporation of the fluorinated monomer 2,2,3,3‐tetrafluoropropyl methacrylate (TFMA) regulates the solvation environment via an electron withdrawing group anion trapping (EWGAT) effect, effectively traps the bis(trifluoromethanesulfonyl)imide anions (TFSI − ) through hydrogen bond interaction, promotes a solvation structure transition from ionic aggregates (AGGs) to contact ion pairs (CIPs), and balances anion‐reinforced solvation structure and ionic conductivity. As a result, the PVPT electrolyte delivers high ionic conductivity of 1.7 mS cm −1 , high Li + transference number of 0.75, and extended electrochemical window up to 5.3 V. Through an in situ polymerization approach, the PVPT electrolyte enables lithium metal batteries (LMBs) with LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathodes to achieve a high capacity retention of 85.64% over 400 cycles. This molecular design of PVPT offers a distinctive, promising strategy for developing high‐performance PECEs toward advanced quasi‐solid‐state lithium batteries with high energy density and long cycle life.

Lithium metal is widely recognized as the ultimate anode material for next-generation lithium batteries due to its superior specific capacity. However, microscopic crystallographic heterogeneity caused by crystal faces and grain boundaries leads to nonuniform lithium deposition, thereby undermining the stability of lithium metal anode. This study systematically investigates the intricate impact of grain boundaries on the structural characteristics, deposition behavior, and electrochemical properties of lithium metal. We demonstrate that grain boundaries serve as preferential nucleation sites, exacerbating morphological heterogeneity. Although eliminating preexisting grain boundaries from substrate facilitates homogeneous lithium nucleation and enhances electrochemical performance, this approach does not address the deposition issues originating from the intercrystalline regions of newly deposited grains. Furthermore, the continuous expansion of the intercrystalline network disrupts single-crystal structure and accelerates anode degradation, imposing a critical constraint on performance enhancement. This work unveils a previously overlooked intercrystalline-driven failure mechanism and provides insights for realizing dendrite-free lithium batteries.

Bismuth has emerged as a promising alloying anode for magnesium‐ion batteries (MIBs), offering high theoretical capacity with a low electrode potential, and thus serving as a viable alternative to Mg metal. Herein, Bi nanoparticle (NP)‐integrated nitrogen‐doped carbon nanostructures (Bi@nCN) are synthesized via a scalable one‐step carbothermal reduction of BiOCl and Mg phthalocyanine. The resulting Bi@nCN features finely dispersed Bi NPs embedded in a nitrogen‐doped carbon matrix, forming a stress‐relieving architecture that accommodates the structural changes associated with the two‐phase reaction between Bi and Mg 3 Bi 2 . Bi@nCN demonstrates excellent electrochemical performance, with high capacity retention, superior rate capability, and minimal polarization growth. Furthermore, full cells employing Bi@nCN anodes exhibit stable operation in chloride‐free electrolytes, including ether‐ and nitrile‐based systems, in which Mg metal typically develops insulating passivation layers. These findings highlight the potential of Bi@nCN to enable stable Mg‐ion storage in chloride‐free electrolytes, overcoming the intrinsic limitations of Mg metal anodes and expanding the scope of MIB chemistry with new electrolyte and cathode combinations.

The direct utilization of seawater as an electrolyte in zinc-ion batteries demonstrates significant potential for energy storage applications. However, the harsh conditions of seawater pose challenges, such as corrosion, dendrite formation, and hydrogen evolution reactions, which severely impede practical implementation. Herein, a series of seawater-corrosion-resistant coating layers (zinc acetylacetonate (ZA)/zinc hydroxide (Zn(OH)2)/zinc oxide (ZnO)/zinc fluoride (ZnF2)/lithium fluoride (LiF)) are respectively constructed on the surface of the zinc anode by ultrasonic spraying technology. Based on the systematic electrochemical tests and theoretical calculations, the ZA layer exhibits superior chloride-ion blocking performance, enhanced zinc affinity and nucleophilicity owing to its unique organometallic complex structure, promoting the desolvation polarization behavior and reversible deposition behavior of Zn2+ ions. Consequently, the ZA@Zn symmetric cell exhibits an outstanding long-cycle performance of 4268h at 5mA cm-2. The Zn//ZA@Cu asymmetric cell exhibits a high Coulombic efficiency (CE) of 99.47% after 650 cycles at 4mA cm-2, and the ZA@Zn//NH4V4O10 battery retains a high capacity of 213.7 mAh g-1 after 2000 cycles at 6 A g-1 with minimal capacity fade. This work will guide future design and fabrication of interface modifications for dendrite-free metal anodes in seawater batteries.

Abstract Lithium metal is regarded as the ultimate anode for high‐energy‐density batteries due to its ultra‐high theoretical specific capacity (3860 mAh g −1 ) and lowest redox potential (−3.04 V vs standard hydrogen electrode). However, lithium dendrite growth remains a major challenge. In this study, a multifunctional interfacial layer is constructed using Fe 3+ ‐doped spinel oxide anchored on carbon nanofibers (CoMnFe@CNF). Through Fe 3+ ‐mediated cation regulation, the spin state of Co 3+ Tetrahedral (Td) is altered to enable directional solvent capture, while Mn 3+ Octahedral (Oh) sites promoted electron delocalization for enhanced desolvation and ion guidance. Density Functional Theory revealed spin‐reconstructed Co 3+ (Oh) sites increased Li⁺ adsorption energy from −0.96 to −3.06 eV via strong Lewis acid–base interactions. Concurrently, Mn 3+ ‐induced electron delocalization accelerated desolvation and optimized ion transport pathways. This enabled a synergistic mechanism of “solvent capture–desolvation promotion–ion guidance” to effectively suppress dendrite formation. The modified lithium anode delivered stable cycling over 2000 h, and demonstrated excellent performance in full cells. This work offers a new strategy for stabilizing lithium metal anodes via spin‐state engineering of spinel oxides, advancing practical lithium metal battery applications.

Abstract Ionic salt additives have long been utilized to tailor the solvation structure of hydrated Zn 2+ in aqueous zinc batteries. However, the influence of cations on zinc ion solvation remains largely unexplored. In this work, for the first time, a cation‐assisted approach is presented and elucidated to promote the desolvation process of [Zn(H 2 O) 6 ] 2+ , thereby enabling highly reversible Zn plating/stripping at elevated current rates. Using sodium lactate as a proof‐of‐concept, it is demonstrated that Na + cations form a novel solvation structure that effectively competes for water molecules in the [Zn(H 2 O) 6 ] 2+ shell. This competition allows more lactate anions to be incorporated into the final solvation structure. The resulting water‐deficient interface on the Zn anode simultaneously suppresses water‐driven side reactions and directs Zn (002) deposition, mitigating dendrite formation. Consequently, the Zn anodes exhibit an exceptional cycling lifespan of 4500 h at a high current density of 20 mA cm −2 , along with stable performance even at 90% depth of discharge and a low negative‐to‐positive capacity ratio of 2.2 in full cells. This work provides a simple yet effective electrolyte engineering strategy to realize durable and deeply cyclable Zn metal anodes.

ABSTRACT Aqueous zinc‐based batteries (ZIBs) are considered promising energy storage solutions, particularly targeting low‐cost applications needed for levelling electricity production from renewable energy sources. However, numerous challenges need to be overcome to bring the technology to the market, chiefly including cathode dissolution, dendrite formation, hydrogen evolution reaction, and zinc corrosion. The optimisation of the electrolyte, particularly the use of gel‐polymer electrolytes (GPEs), is demonstrated as a viable approach to solve or mitigate such issues. In this respect, a comparative study of two GPEs based on biopolymers, agarose and sodium alginate, is presented here. Despite the fast and facile preparation procedure, the GPEs demonstrate to be strongly effective in suppressing dendrite and byproduct formation on zinc metal anodes, due to the abundant ─OH groups along the chains in polymeric matrices. The electrochemical behaviour of GPEs is evaluated in terms of galvanostatic cycling in laboratory‐scale zinc metal cells with a CaV 6 O 16 ·3H 2 O cathode at low and high active material loadings of 2.5 and 5 mg cm − 2 , respectively. Resulting cycling performances in terms of specific capacity and rate capability are comparable (low loading electrodes) and even outperform (high loading electrodes) those obtained with a standard liquid electrolyte (2M ZnSO 4 ) laboratory‐scale cell, thus accounting for the promising prospects of the bio‐polymer GPEs as an alternative green, sustainable electrolyte for next‐generation Zn‐based batteries.

Lithium metal anodes are promising for next‐generation batteries due to their ultrahigh theoretical capacity (3860 mAh g −1 ) and low redox potential. Anode‐free lithium metal batteries offer enhanced energy density by eliminating prelithiated anodes. However, lithium's high reactivity causes dendrite growth, risking short circuits, while the unstable solid electrolyte interphase consumes active lithium and electrolyte, reducing cycle life and Coulombic efficiency (CE). Commercial copper foil current collectors, though conductive, promote uneven lithium deposition due to their smooth surfaces.Therefore, the modification of the Cu‐based current collectors to reduce local current density, inhibit dendrite growth, and improve CE has been widely studied and reported. Herein, methods for modifying Cu‐based current collectors are systematically summarized to guide the rational design of these modifications.

Abstract Aqueous Zn‐ion batteries (AZIBs) suffer from irreversible Zn anodes due to solvated H 2 O‐induced dendrite growth and side reactions. Herein, a loose and H 2 O‐poor solvation structure of Zn 2+ via electrostatic engineering using a low dielectric constant ( ɛ ≈ 7) co‐solvent 1, 3‐dioxolane (DOL) is designed. The DOL weakens the shielding effect on the cation–anion electrostatic interactions, driving anion‐rich Zn 2+ solvation structure ([Zn 2+ (H 2 O) 2.7 (OTf − ) 2.2 DOL 1.1 ]) while elongating the bond length of Zn 2+ −H 2 O via steric hindrance. These features effectively decrease the reducibility of H 2 O, accelerate Zn 2+ desolvation kinetics ( E a : 17.93 vs 32.21 kJ mol −1 ) and foster a robust inorganic‐rich solid electrolyte interphase (SEI). Consequently, the Zn anodes achieve an impressive cycling stability under triple‐high conditions (50 mA cm −2 , 50 mAh cm −2 , 68.9% depth of discharge (DOD)) for 1300 h, with a record cumulative plated capacity of 32.5 Ah cm −2 . Furthermore, the Zn/NaV 3 O 8 ·1.5H 2 O full cell retains 95.2% capacity after 2000 cycles. The universality of this strategy is validated by alternative co‐solvent with comparable ɛ , DN and steric hindrance properties to DOL, including 1,2‐dimethoxyethane (DME), benzyl alcohol (BA) and tetrahydrofuran (THF). This work establishes a general design guideline for stable aqueous metal anodes through solvation electrostatic modulation.

Molecular isolation layer constructed by planar conjugated organic molecules for highly durable Na/K metal anodes

A molten-based ultrathin lithium metal anode manufacturing method

HighlightsElectrochemical phase-field model.Concurrent electrochemical reaction, heat transfer, separator thermal deformation.Dependence of dendrite descriptors on separator thermophysical parameters.Thermal conductivity, thermal deformation, and thermal shutdown of separator.

Pyrrole-enabled free water activity suppression and zincophilic-hydrophobic interfacial engineering for highly stable Zn metal anode

Fluorine-free SEI enabling highly reversible zinc metal anode for low-cost and environment-friendly aqueous zinc-metal batteries