In-situ construction of lithophilic Li3Sb layer on nickel foam to induce low nucleation barrier and uniform deposition for stable lithium-metal anode.

The widespread research for lithium metal anodes (LMA) has been rapidly developed in recent years. However, undesirable dendritic structures generated in the process of unstable lithium (Li) deposition dramatically restricts the cycle life of LMA. The skeleton structure of the three-dimensional (3D) host substrates are the potential promising host for Li, which can alleviate volume expansion during cycling. Herein, we propose a facile surface modification approach through ion sputtering, which can effectively regulate the lithiophilic properties of Cu foam (CF) for facilitating Li deposition. Au modified surface can enhance the lithiophilic property of substrates and induce uniform Li deposition along the conductive skeleton. Further analysis of results, substrate with Au coating modified surface exhibits a smaller Li nucleation overpotential (12 mV), a more stable coulombic efficiency (CE) at different current densities, and more uniform morphology of Li deposition with dendrite-free at large capacity of 4 mAh cm-2. Meanwhile, symmetric cells with Au coating on CF can stably operate more lifespan than other samples. Furthermore, full cells paired with LiFePO4 cathodes and CF coated Au exhibit remarkable discharge capacities and capacity retention than others. This work provides new insights toward developing excellent 3D skeleton with modified surface for dendrite-free LMA.

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 N3-Bi-S1 moiety anchored on interconnected carbon tubes (Bi-N3S1@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-N3S1@CT achieves an extraordinary average Coulombic efficiency (CE) of 99.6% over 900 cycles at 12mA cm-2 and 6 mAh cm-2, along with long-term durability of 1000h at 10mA cm-2 and 10 mAh cm-2 in symmetric cells. Notably, an anode-free pouch cell paired with a high-loading Na3V2(PO4)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.

The high Li+ desolvation energy barrier causes sluggish kinetics and uncontrolled dendrite growth, leading to severe solid electrolyte interface (SEI) instability and hindered ion transport across lithium-metal anodes (LMAs), which remains a major barrier to commercialization. Herein, a Lewis-based N/O dual-functional covalent organic polymer (COP-DQCC) with abundant carbonyl components was designed and integrated into a commercial polypropylene (PP) separator. Experimental and theoretical calculations show that the high lithiophilicity of Lewis base N/O atoms enhances lithium salt dissociation, promotes Li+ desolvation from the solvation shell, reduces solvent molecule transport, simplifies the solvated structure of Li+, lowers ion diffusion activation energy, and accelerates Li+ migration. Additionally, the suitable pore size of the triazine composite carbonyl organic unit regulates the electroplating/stripping behavior of LMA. In situ optical microscopy reveals that the COP-DQCC layer effectively inhibited dendrite growth. Time-of-flight secondary ion mass spectrometry further confirms that the COP-DQCC layer promotes the formation of a stable LiF-rich SEI layer, regulates Li+ transport and uniform deposition. Ultimately, the Li/COP-DQCC@PP/Li symmetric cell demonstrated stable cycling for over 2400 h at 1.0 mA cm-2/1.0 mAh cm-2, maintaining a low overpotential, and continued stable cycling for over 900 h at 4.0 mA cm-2/4.0 mAh cm-2. Additionally, the LiFePO4/COP-DQCC@PP/Li cell shows remarkable cycling stability, retaining 84.6% of its capacity after 1200 cycles at 1.0 C, and excellent cycling performance at higher loading of LiFePO4. This work highlights the development of a durable, dendrite-free anode, offering significant potential for advancing high-energy-density LMAs.

Uneven lithium (Li) metal deposition typically results in uncontrollable dendrite growth, which renders an unsatisfactory cycling stability and coulombic efficiency (CE) of Li metal batteries (LMBs), preventing their practical application. Herein, a novel carbon cloth with the modification of ZnO nanosheets (ZnO@CC) is fabricated for LMBs. The as-prepared ZnO@CC with a cross-linked network significantly reduces the local current density, and the design of ZnO nanosheets can promote the uniform deposition of Li metal as lithiophilic sites. As a result, the Li metal anodes (LMAs) based on ZnO@CC (ZnO@CC@Li) enables a long cycle life over 640 hours with a low overpotential of 65 mV at a current density of 4 mA cm-2 with a capacity of 1 mAh cm-2 in the symmetric cell. Moreover, when coupling the ZnO@CC@Li with a LiFePO4 cathode, the assembled full cell exhibits excellent long cycle and rate performance, highlighting its promising practical application prospect.

To unlock the great potential of lithium metal anodes for high-performance batteries, a number of critical challenges must be addressed. The uncontrolled dendrite growth and volume changes during cycling (especially, at high rates) will lead to short lifespan, low Coulombic efficiency (CE), and security risks of the batteries. Here it is reported that Li metal anodes, employing the monodisperse, lithiophilic, robust, and large-cavity N-doped hollow carbon nanospheres (NHCNSs) as the host, show remarkable performances-high areal capacity (10mAhcm-2), high CE (up to 99.25% over 500 cycles), complete suppression of dendrite growth, dense packing of Li anode, and an extremely smooth electrode surface during repeated Li plating/stripping. In symmetric cells, a highly stable voltage hysteresis over a long cycling life >1200 h is achieved, and a low and stable voltage hysteresis can be realized even at an ultrahigh current density of 64mAcm-2. Furthermore, the NHCNSs-based anodes, when paired with a LiFePO4 (LFP) cathode in full cells, give rise to highly improved rate capability (104mAhg-1 at 10 C) and cycling stability (91.4% capacity retention for 200 cycles), enabling a promising candidate for the next-generation high energy/power density batteries.

Lithium (Li) or zinc (Zn) metal anodes have attracted interest for battery research due to their high theoretical capacities and low redox potentials. However, uncontrollable dendrite growth, especially under high current (>4 mA cm-2), precludes reversable cycling in Li or Zn metal batteries with a high-loading (>4 mAh cm-2), precludes reversable cycling in Li or Zn metal batteries with high-loading (>4 mAh cm-2) cathode. We report a cation regulation mechanism to address this failure. Collagen hydrolysate coated on absorbed glass mat (CH@AGM) can simultaneously induce a deionization shock inside the separator and spread cations on the anode to promote uniform electrodeposition. Employing 24 mAh cm-2 cathodes, Li and Zn metal batteries with CH@AGM delivered 600 cycles with a Coulombic efficiency of 99.7%. In comparison, pristine Li and Zn metal batteries only survive for 10 and 100 cycles, respectively. This approach enabled 400 cycles in a 200 Ah-class Zn metal battery, which suggests a scalable method to achieve dendrite-free anodes in various batteries.

Sodium (Na) metal is considered a promising anode material for high-energy Na batteries due to its high theoretical capacity and abundant resources. However, uncontrollable dendrite growth during the repeated Na plating/stripping process leads to the issues of low Coulombic efficiency and short circuits, impeding the practical applications of Na metal anodes. Herein, we propose a silver-modified carbon nanofiber (CNF@Ag) host with asymmetric sodiophilic features to effectively improve the deposition behavior of Na metal. Both density functional theory (DFT) calculations and experiment results demonstrate that Na metal can preferentially nucleate on the sodiophilic surface with Ag nanoparticles and uniformly deposit on the whole CNF@Ag host with a "bottom-up growth" mode, thus preventing unsafe dendrite growth at the anode/separator interface. The optimized CNF@Ag framework exhibits an excellent average Coulombic efficiency of 99.9% for 500 cycles during Na plating/stripping at 1 mA cm-2 for 1 mAh cm-2. Moreover, the CNF@Ag-Na symmetric cell displays stable cycling for 500 h with a low voltage hysteresis at 2 mA cm-2. The CNF@Ag-Na//Na3V2(PO4)3 full cell also presents a high reversible specific capacity of 102.7 mAh g-1 for over 200 cycles at 1 C. Therefore, asymmetric sodiophilic engineering presents a facile and efficient approach for developing high-performance Na batteries with high safety and stable cycling performance.

Highly lithiophilic ZnO nanosheets decorated Ni foam as a stable host for high-performance lithium metal anodes

Controlled lithium plating in three-dimensional hosts through nucleation overpotential regulation toward high-areal-capacity lithium metal anode

Zn metal, as one of the most promising anode materials for aqueous batteries, suffers from uncontrollable dendrite growth and water-induced parasitic reactions, which drastically compromise its cycle life and Coulombic efficiency (CE). Herein, a nonionic amphipathic additive Tween-20 (TW20) is proposed that bears both zincophilic and hydrophobic units. The zincophilic segment of TW20 preferentially adsorbs on the Zn anode, while the hydrophobic segment is exposed on the electrolyte side, forming an electrolyte-facing hydrophobic layer that shields the anode from active water molecules. Moreover, theoretical calculation and experimental results reveal that the TW20 additive can induce the preferential growth of (002) plane by adsorbing on other facets, enabling dendrite-free Zn anodes. Benefitting from these advantages, the stability and reversibility of Zn anodes are substantially improved, reflected by stable cycling for over 2500h at 1.0mA cm-2 /1.0 mAh cm-2 and 500h at 5mA cm-2 /5 mAh cm-2 as well as an average CE of 99.4% at 1.0mA cm-2 /1.0 mAh cm-2 . The full cells paired with MnO2 demonstrate a long lifespan for more than 700 cycles at 500mA g-1 . This work is expected to provide a new approach to modulate Zn electrode interface chemistry for highly stable Zn anodes.

Lithium (Li) metal anode, one of the most promising candidates for next-generation rechargeable batteries, has always suffered from uneven Li deposition/stripping. To address this issue, this work designs a novel nickel-carbon composite modified Li metal anode (FNC-NF) by carbonizing fluoride nickel hydroxide nanosheet arrays grown on nickel foam (NF). These electrochemical tests present that the conductive and lithiophilic FNC can effectively restrain the growth of Li dendrites during the cycling of Li deposition/stripping at large capacities up to 10 mAh cm-2. This result is attributed to the featured FNC composition combining a core of nickel hydroxide and a mixed coating of defective carbon and Ni nanoparticles, and the unique hierarchical morphology of the FNC-NF integrating porous NF and vertically aligned FNC nanosheets. Consequently, the FNC-NF presents a stable coulombic efficiency performance after 900 cycles with an average of 99.23% for half cells, a lifespan over 3200 h for symmetric cells at 1 mA cm-2 and 1 mAh cm-2, and a remarkable cycling stability at large current densities of up to 15 mA cm-2 at 1 mAh cm-2. Moreover, the Li||FNC-NF||LiFePO4 full cells show superior capacity retention and cycling stability at 1 C.

Uncontrollable dendrite growth and low Coulombic efficiency are the two main obstacles that hinder the application of rechargeable Li metal batteries. Here, an optimized amount of potassium hexafluorophosphate (KPF6, 0.01 M) has been added into the 2 M LiTFSI/ether-based electrolyte to improve the cycling stability of lithium-sulfur (Li-S) batteries. Due to the synergistic effect of self-healing electrostatic shield effect from K+ cations and the LiF-rich solid electrolyte interphases derived from PF6- anions, the KPF6 additive enables a high Li Coulombic efficiency of 98.8% (1 mA cm-2 of 1 mAh cm-2). The symmetrical Li cell can achieve a stable cycling performance for over 200 cycles under a high Li utilization up to 33.3%. Meanwhile, the polysulfide shuttle has been restrained due to the higher concentration of the LiTFSI in the electrolyte. As a result, the assembled Li-S full cell displays excellent capacity retention with only 0.25% decay per cycle in the final electrolyte. Our work offers a smart approach to improve both the anode and cathode performance by the electrolyte modification of rechargeable Li-S batteries.

In developing advanced lithium (Li) metal batteries with high-energy density, excellent cycle stability, and high-rate capability, it is imperative to resolve dendrite growth and volume expansion during repeated Li plating/stripping. 3D hosts featuring lithiophilic sites are expected to realize both spatial control and dendrite inhibition over Li nucleation. Herein, this work prepares silver (Ag) nanoparticle-decorated 3D copper (Cu) foam via a facile replacement reaction. The 3D host provides rigid skeleton to accommodate volume expansion during cycling. Ag nanoparticles show micro-structural affinity to guide efficient nucleation of Li, leading to reduced overpotential and enhanced electrochemical kinetics. As the result, under an ultrahigh current density of 10 mA cm-2, Cu@Ag foam/Li half cells demonstrate outstanding Coulombic efficiency (CE) of 97.2% more than 100 cycles. Also, Cu@Ag foam-Li symmetric cells sustain preeminent cycling over 900 h with a small voltage hysteresis of 32.8 mV at 3 mA cm-2. Moreover, the Cu@Ag foam-Li||LiFePO4 full cell demonstrates a high discharge capacity of 2.33 mAh cm-2 over 200 cycles with an excellent CE up to 99.9% at 0.6C under practical conditions (N/P = 1.3, 17.4 mg cm-2 LiFePO4). Notably, the full cell with LiFePO4 exhibits a higher areal capacity of 1 mAh cm-2 over 700 cycles under a high rate of 5C, corresponding to capacity retention up to 100% (N/P = 3, 17.4 mg cm-2 LiFePO4). This study provides a novel and simple strategy for constructing high-rate and long-life Li metal batteries.

3D hosts are promising to extend the cycle life of lithium metal anodes but have rarely been implemented with lean electrolytes thus impacting the practical cell energy density. To overcome this challenge, a 3D host that is lightweight and easy to fabricate with optimum pore size that enables full utilization of its pore volume, essential for lean electrolyte operations, is reported. The host is fabricated by casting a VGCF (vapor‐grown carbon fiber)‐based slurry loaded with a sparingly soluble rubidium nitrate salt as an additive. The network of fibers generates uniform pores of ≈3 µm in diameter with a porosity of 80%, while the nitrate additive enhances lithiophilicity. This 3D host delivers an average coulombic efficiency of 99.36% at 1 mA cm−2 and 1 mAh cm−2 for over 860 cycles in half‐cell tests. Full cells containing an anode with 1.35‐fold excess lithium paired with LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes exhibit capacity retention of 80% over 176 cycles at C/2 under a lean electrolyte condition of 3 g Ah−1. This work provides a facile and scalable method to advance 3D lithium hosts closer to practical lithium‐metal batteries.

Metallic sodium (Na) has been regarded as one of the most attractive anodes for Na-based rechargeable batteries due to its high specific capacity, low working potential, and high natural abundance. However, several important issues hinder the practical application of the metallic Na anode, including its high reactivity with electrolytes, uncontrolled dendrite growth, and poor processability. Metal nitrates are common electrolyte additives used to stabilize the solid electrolyte interphase (SEI) on Na anodes, though they typically suffer from poor solubility in electrolyte solvents. To address these issues, a Na/NaNO3 composite foil electrode was fabricated through a mechanical kneading approach, which featured uniform embedment of NaNO3 in a metallic Na matrix. During the battery cycling, NaNO3 was reduced by metallic Na sustainably, which addressed the issue of low solubility of an SEI stabilizer. Due to the supplemental effect of NaNO3, a stable SEI with NaNxOy and Na3N species was produced, which allowed fast ion transport. As a result, stable electrochemical performance for 600 h was achieved for Na/NaNO3||Na/NaNO3 symmetric cells at a current density of 0.5 mA cm-2 and an areal capacity of 0.5 mAh cm-2. A Na/NaNO3||Na3V2(PO4)2O2F cell with active metallic Na of ∼5 mAh cm-2 at the anode showed stable cycling for 180 cycles. In contrast, a Na||Na3V2(PO4)2O2F cell only displayed less than 80 cycles under the same conditions. Moreover, the processability of the Na/NaNO3 composite foil was also significantly improved due to the introduction of NaNO3, in contrast to the soft and sticky pure metallic Na. Mechanical kneading of soft alkali metals and their corresponding nitrates provides a new strategy for the utilization of anode stabilizers (besides direct addition into electrolytes) to improve their electrochemical performance.