Li Deposition Research Articles

Facile Polymer of Intrinsic Microporosity-Modified Separator with Quite-Low Loading for Enhanced-Performance Lithium Metal Batteries.

Lithium metal batteries (LMBs) using Li metals as anodes are conspicuous for high-energy-density energy-storage devices. However, the nonuniform deposition of Li+ ions leading to uncontrolled Li dendrite growth, which adversely affects electrochemical performance and safety, has impeded the practical application of lithium metal batteries (LMBs). Herein, PIM-1, a type of polymer of intrinsic microporosity (PIM), was utilized for surface engineering of conventional polyolefin separators. This process resulted in the formation of a continuous and homogeneous coating across the separator, facilitating uniform Li+ ion flux and deposition, and consequently reducing dendrite formation. Notably, the loading mass was quite low (0.6 g/m2) through the convenient dipping method. The intrinsic micropores and polar groups (cyano and ether groups) of PIM-1 greatly improved the electrolyte wettability and ionic conductivity of commercial polypropylene (PP) separators. And the PIM-1 coating guided Li+ flux to achieve uniform Li deposition. Moreover, the polar groups (cyano and ether groups) of PIM-1 are beneficial to the desolvation of Li+-solvates. As a result, the synergetic effect of uniform Li+ flux, desolvation, and enhanced mechanical strength of separators brings about considerable improvement in cycle life, suppression of Li dendrite, and Coulombic efficiency for LMBs. As this surface engineering is simple, relatively low-cost, and effective, this work provides fresh insights into separators for LMBs.

Surface fluorination of nickel nanowires enabling LiF-rich nanoscale solid electrolyte interface for stable lithium anodes

Lithium (Li) metal has become a research hotspot for anodes materials due to its ultra-high theoretical capacity and the lowest redox potential. However, the practical application of Li metal batteries is hampered by the formation of uncontrollable Li dendrites and the irreversible structural changes during long-term charge/discharge processes. Developing stable Li metal anode with uniform Li deposition is highly desirable. Herein, surface fluorination of nickel nanowires enabling LiF-rich nanoscale solid electrolyte interface was demonstrated for stable Li anodes. Free-standing three-dimensional (3D) nickel nanowires (NiNWs) current collector decorated with lithiophilic NiF2 nanosheets (NiNWs@NiF2) was constructed via a simple and scalable fluorination strategy. Theoretical and experimental analysis confirmed that the lithiophilic surface of NiF2 nanosheets could reduce the Li nucleation barrier, facilitating uniform Li ion deposition. The 3D conductive NiNWs network enabled fast electron transfer and mitigated volume changes during cycling. Additionally, a LiF-rich nanoscale solid electrolyte interface (SEI) layer formed between Li and the electrolyte significantly improved the interfacial stability. As a result, the as-assembled Li-NiNWs@NiF2 symmetrical cell provided a superior electrochemical performance, maintaining stability for 2500 h at 1.0 mA cm−2 and 900 h at 5.0 mA cm−2. Furthermore, the assembled Li-NiNWs@NiF2|| LiFePO4 (LFP) full cell demonstrated exceptional capacity retention of 93.9 % after 2000 cycles at a rate of 5C. Overall, the unique structure of NiNWs@NiF2 not only offers a straightforward method for designing a 3D lithiophilic host, but also provides the concept of interfacial engineering through the in-situ construction of an artificial LiF-rich nanoscale SEI layer.

Bonded Interface Enabled Durable Solid‐state Lithium Metal Batteries with Ultra‐low Interfacial Resistance of 0.25 Ω cm2

AbstractThe solid‐state batteries (SSBs) with Li anode present one of the most promising energy storage systems due to their enhanced energy density and safety. However, interfacial problems between Li anode and solid‐state electrolyte hinder the advancement of SSBs. Among them, insufficient solid‐solid interfacial contact is the main issue, which causes large resistance and hinders Li+ diffusion, leading to current distribution unevenness and lithium dendrites growth. To meet these challenges, a silver/carbon interlayer composed of ultrafine Ag nanoparticles (≈5 nm) grown on COOH‐CNTs (nano‐Ag@COOH‐CNTs) is constructed. In which, nano‐Ag is designed to guide homogeneous Li deposition, while CNTs substrate bonds with Li6.5La3Zr1.5Ta0.5O12 (LLZTO) electrolyte by reactions between ─COOH groups and LLZTO alkaline surface, thus transforming loose physical solid‐solid contact to chemical bonding contact. In addition, nano‐Ag is immobilized by CNTs, avoiding the migration of Li+ implanted nano‐Ag during cycling. Therefore, nano‐Ag@COOH‐CNTs interlayer can boost Li+ transport at LLZTO/Li interface and inhibit Li dendrites, achieving an ultra‐low interfacial resistance of 0.25 Ω cm2, a high critical current density of 1.7 mA cm−2 and a long cycling over 2155 h at 0.5 mA cm−2. The modified SSBs with LiNi0.83Co0.12Mn0.05O2 cathode cycles stably over 500 cycles. Moreover, high‐loading SSBs operate stably for 85 cycles.

Kelvin Probe Force Microscopy and Electrochemical Atomic Force Microscopy Investigations of Lithium Nucleation and Growth: Influence of the Electrode Surface Potential.

Lithium metal is promising for high-capacity batteries because of its high theoretical specific capacity of 3860 mAh g-1 and low redox potential of -3.04 V versus the standard hydrogen electrode. However, it encounters challenges, such as dendrite formation, which poses risks of short circuits and safety hazards. This study examines Li deposition using electrochemical atomic force microscopy (EC-AFM) and Kelvin probe force microscopy (KPFM). KPFM provides insights into local surface potential, while EC-AFM captures the surface response evolution to electrochemical reactions. We selectively removed metallic coatings from current collectors to compare lithium deposition on coated and exposed copper surfaces. Observations from the Ag-coated Cu (Ag/Cu), Pt-coated Cu (Pt/Cu), and Au-coated Cu (Au/Cu) samples revealed variations in lithium deposition. Ag/Cu and Au/Cu exhibited two-dimensional growth, whereas Pt/Cu exhibited three-dimensional growth, highlighting the impact of electrode materials on morphology. These insights advance the development of safer lithium metal batteries.

Unraveling the multilayer solid-electrolyte interphase in lithium batteries through depth-sensitive plasmon-enhanced Raman spectroscopy: A theoretical and experimental study

The solid-electrolyte interphase (SEI) plays a crucial role in determining the lithium deposition/dissolution behaviors, thus influencing the reversible operation of Li metal batteries renowned for their ultrahigh specific capacity. Recently, we developed a depth-sensitive plasmon-enhanced Raman spectroscopy (DS-PERS) method enabling the in situ and nondestructive characterization of the nanostructure and chemistry of SEI through synergistic plasmonic structures. However, a lack of comprehensive elucidation of the enhancement mechanisms has impeded a detailed understanding of the depth-resolved signal contributions. In this study, we integrate theoretical computations with experimental methodologies to systematically unravel the working principles of the synergistic plasmonic structures, demonstrating that hot spots can effectively detect Raman signals at key locations across various stages of SEI layer evolution. Following Li deposition, the hot spots transfer from the Cu interfaces to the Li interfaces. With the thickening of the deposited Li, the localized surface plasmon resonance of Cu is gradually shielded, leading to the disappearance of hot spots originated from Li-Li coupling. Subsequently, we propose the utilization of Cu@Li-multilayer shell-isolated nanoparticles to compensate and introduce new hot spots, thereby enhancing the depth sensitivity. Our work provides theoretical insights essential for achieving precise depth-resolved PERS characterization.

Lithiophilic Multichannel Layer to Simultaneously Control the Li-Ion Flux and Li Nucleation for Stable Lithium Metal Batteries.

Although the Li metal has been gaining attention as a promising anode material for the next-generation high-energy-density rechargeable batteries owing to its high theoretical specific capacity (3860 mAh g-1), its practical use remains challenging owing to inherent issues related to Li nucleation and growth. This paper reports the fabrication of a lithiophilic multichannel layer (LML) that enables the simultaneous control of Li nucleation and growth in Li-metal batteries. The LML, composed of lithiophilic ceramic composite nanoparticles (Ag-plated Al2O3 particles), is fabricated using the electroless plating method. This LML provides numerous channels for a uniform Li-ion diffusion on a nonwoven separator. Furthermore, the lithiophilic Ag on the Li metal anode surface facing the LML induces a low overpotential during Li nucleation, resulting in a dense Li deposition. The LML enables the LiNi0.8Co0.1Mn0.1O2|| Li cells to maintain a capacity higher than 75% after 100 cycles, even at high charge/discharge rates of 5.0 C at a cutoff voltage of 4.4 V, and achieve an ultrahigh energy density of 1164 Wh kg-1. These results demonstrate that the LML is a promising solution enabling the application of Li metal as an anode material in the next-generation Li-ion batteries.

Lithium surface engineering with in-situ generated Fe/Li2O/LiCl mixed electron/ion conductive layer for stable lithium metal batteries

The lithium metal batteries (LMBs) using metallic Li as anode with high-energy density have been prevailed in the field of energy storage, while the aggregation of Li dendrites and brittle solid state electrolyte interface (SEI) impede the development of Li anode. In this work, to regulate the interface of Li anode, a Fe/Li2O/LiCl mixed electron/ion conducting layer is in-situ generated on the surface of Li anode, which is derived from the electrochemical reaction between Li anode and Fe2O3/FeOCl coatings on commercial separator. The synergistic effect between electron conductive Fe and ion conductive Li2O/LiCl is beneficial to build up dense and uniform SEI and promote uniform Li+ flux, resulting in smooth Li deposition, which will further stabilize the Li metal surface and prolong the battery life of LMBs. Specifically, the symmetric Li||Li cells with Fe2O3/FeOCl can operate steadily for 600 h at 1 mAh cm−2 without obvious voltage polarization, and the corresponding full battery matched with S-PAN delivers capacity retention of 64.43 % at 500 mA g−1 after 350 cycles.

An ultrathin and robust single-ion conducting interfacial layer for dendrite-free lithium metal batteries

The practical application of rechargeable lithium metal batteries (LMBs) encounters significant challenges due to the notorious dendrite growth triggered by uneven Li deposition behaviors. In this work, a mechanically robust and single-ion-conducting interfacial layer, fulfilled by the strategic integration of flexible cellulose acetate (CA) matrix with rigid graphene oxide (GO) and LiF fillers (termed the CGL layer), is rationally devised to serve as a stabilizer for dendrite-free lithium (Li) metal batteries. The GCL film exhibits favorable mechanical properties with high modulus and flexibility that help to relieve interface fluctuations. More crucially, the electron-donating carbonyl groups (C=O) enriched in GCL foster a strengthened correlation with Li+, which availably aids the Li+ desolvation process and expedites facile Li+ mobility, yielding exceptional Li+ transference number of 0.87. Such single-ion conductive properties regulate rapid and uniform interfacial transport kinetics, mitigating the growth of Li dendrites and the decomposition of electrolytes. Consequently, stable Li anode with prolonged cycle stabilities and flat deposition morphologies are realized. The Li||LiFePO4 full cells with CGL protective layer render an outstanding cycling capability of 500 cycles at 3 C, and an ultrahigh capacity retention of 99.99% for over 220 cycles even under harsh conditions. This work affords valuable insights into the interfacial regulation for achieving high-performance LMBs.

Amphiphilic molecule-assisted perfluoro-alkanes electrolyte for low temperature lithium metal batteries

Low-temperature working is a big challenge for lithium metal batteries (LMBs), as the efficiency and dendrite growth problems are exacerbated at lower temperature, and meanwhile the impact of slow ion-transfer and difficult ion-desovation is intensified. Herein, the amphiphilic effect of hydrofluoroether was revealed, and fully utilized to construct a nonflammable perfluoro-alkanes electrolyte. With the well-regulated Li+ solvation and the purposedly tuned SEI, the electrolyte brought highly reversible Li deposition from − 60 °C to 60 °C. As a result, Li/LiFePO4 cell (1.5 mAh cm−2) with thin Li anode presented ultra-long cycling life. The work supplies a new design concept for low-temperature LMBs electrolyte.

Distribution of trace elements in growth zones and sectors of spodumene crystals (Pashki deposit, Nuristan, Afghanistan)

Regular distribution of several trace elements in spodumene crystals of the Pashki pegmatite Li deposits in Afghanistan (Nuristan province) is analyzed using secondary ion mass spectrometry (SIMS). Twenty seven local analyses of 19 elements were carried out in spodumene samples of different generations taken from pegmatites during feld works of 2023. We studied an early generation spodumene crystal from blocky spodumene-quartz-albite pegmatite and two late generation spodumene crystals including an euhedral crystal from a quartz core of pegmatite and a crystal extracted from a mineralized cavity together with quartz crystal, albite, and muscovite. It is found that the Fe, B, and Be content is signifcantly higher in the growth pyramid of the pinacoid face (010) than in the growth pyramid of the prism face (021). From early to late growth zones, the Be, B, Fe, and Mn content increases and the K, Rb and Ti content decreases. The heterogeneity of trace element composition of spodumene crystals thus mostly depends on their sectoriality, which is caused by different crystal chemical conditions of the incorporation of isomorphic trace elements into the mineral structure on faces parallel and perpendicular to the direction of pyroxene chains of Si–O tetrahedra along axis [001] rather than by their zonation. From early to late generations of spodumene, the content of most analyzed trace elements signifcantly decreases corresponding to the ideas about the change in the crystallization fractionation of elements during the evolution of the pegmatite process transiting from the closed to open physicochemical system.

Cyclability Investigation of Anode-Free Lithium-Metal Batteries

Lithium (Li) is a sought-after element for thrift, and considerable effort is being invested in conserving, reusing, and optimizing its chemical capabilities as a key material for energy storage systems. Anode-free lithium-metal batteries (AFLMB) provide the ability to utilize the exact amount of Li in the battery, thereby increasing both the specific capacity and safety of the battery. AFLMBs are widely recognized and investigated due to their promised benefits but have not yet become commercial, primarily because they suffer from uneven Li deposition. This issue results in Li dendrite formation, electrolyte consumption due to poor solid electrolyte interphase properties, and, generally, safety concerns. Overcoming these challenges would bring humanity one step closer to a desirable zero-carbon emission future, as more energy could be stored in less volume and weight. In this study, we examined an AFLMB system and investigated different physical and electrochemical factors to understand their effects on the nature of Li deposition/dissolution processes and on the cyclability of the battery. The effects of electrode architecture, cycling temperature, current density in the first charge, and salt composition on the battery were investigated using electrochemical impedance spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy.

A new type of clay-Li deposit: Fault-controlled hydrothermal alteration in southern Hubei Province, China

Clay-Li deposits are among the major Li deposits in the world and occur mainly in sedimentary and/or volcanic-sedimentary strata. The Li orebodies are generally stratiform and stratibound, and Li is mainly hosted in various clay minerals. Here, we report a new type of clay-Li deposit that occurs along fault zones developed in metasedimentary rocks with significant alteration, and Li is also hosted in clay minerals in the Jinyinshan area in Xianning, southern Hubei Province, China. The study area has no granitic rock outcrops, but approximately 15 km south is the Mufushan granite batholith, where large-scale rare metal mineralization, such as Li, Be, Nb and Ta granitic pegmatites, developed in the internal and outer contact zones of the granite batholith. In this study, high-Li clay minerals, including chlorite, kaolinite and smectite, were identified. The enrichment of Li is closely related to hydrothermal activity along the F9 fault in the region. Hydrothermal apatite coexisting with Li-clay in the orebody along the fault zone yielded an in situ U–Pb age of 135.2 ± 13.9 Ma, which is in good agreement with the ages of granites and Li-pegmatites around the Mufushan batholith. Petrographic, geochemical, and chronological evidence suggests that the ore-forming fluids and Li were likely sourced from the Mufushan granite batholith or a similar blind granite at the depth of the study area; that is, the granite-derived ore-forming fluids can travel long distances along fault zones, and during this pathway, Li from the metasedimentary rocks (i.e., the Lengjiaxi Group) may also have been leached by the fluids and contributed to the Li mineralization in the Jinyinshan clay-Li deposit. The close spatial relationships among different clay minerals indicate that fluid physical–chemical conditions (changes in temperature) may play a crucial role in controlling the formation of Li-rich clay minerals. Our study indicates that the Mufushan area has great potential for hydrothermal clay-Li mineralization occurring in the Lengjiaxi Group metasedimentary rocks around the Mufushan batholith.

Chemical Prelithiated 3D Lithiophilic/-Phobic Interlayer Enables Long-Term Li Plating/Stripping.

The up-to-date lifespan of zero-excess lithium (Li) metal batteries is limited to a few dozen cycles due to irreversible Li-ion loss caused by interfacial reactions during cycling. Herein, a chemical prelithiated composite interlayer, made of lithiophilic silver (Ag) and lithiophobic copper (Cu) in a 3D porous carbon fiber matrix, is applied on a planar Cu current collector to regulate Li plating and stripping and prevent undesired reactions. The Li-rich surface coating of lithium oxide (Li2O), lithium carboxylate (RCO2Li), lithium carbonates (ROCO2Li), and lithium hydride (LiH) is formed by soaking and directly heating the interlayer in n-butyllithium hexane solution. Although only a thin coating of ∼10 nm is created, it effectively regulates the ionic and electronic conductivity of the interlayer via these surface compounds and reduces defect sites by reactions of n-butyllithium with heteroatoms in the carbon fibers during formation. The spontaneously formed lithiophilic-lithiophobic gradient across individual carbon fiber provides homogeneous Li-ion deposition, preventing concentrated Li deposition. The porous structure of the composite interlayer eliminates the built-in stress upon Li deposition, and the anisotropically distributed carbon fibers enable uniform charge compensation. These features synergistically minimize the side reactions and compensate for Li-ion loss while cycling. The prepared zero-excess Li metal batteries could be cycled 300 times at 1.17 C with negligible capacity fading.

An Ultralight Composite Current Collector Enabling High-Energy-Density and High-Rate Anode-Free Lithium Metal Battery.

Anode-free lithium (Li) metal batteries are promising alternatives to current Li-ion batteries due to their advantages such as high energy density, low cost, and convenient production. However, the copper (Cu) current collector accounts for more than 25 wt% of the total weight of the anode-free battery without capacity contribution, which severely reduces the energy and power densities. Here, a new family of ultralight composite current collectors with a low areal density of 0.78mg cm-2, representing significant weight reduction of 49%-91% compared with the Cu-based current collectors for high-energy Li batteries, is presented. Rational molecular engineering of the polyacylsemicarbazide substrate enables enhanced interfacial interaction with the sputtered Cu layer, which results in excellent interfacial stability, flexibility, and safety for the obtained anode-free batteries. The battery-level energy density has been significantly improved by 36%-61%, and a maximum rate capability reaches 5 C (10mA cm-2) attributed to the homogeneous Li+ flux and smooth Li deposition on the nanostructured Cu layer. The results not only open a new avenue to improve the energy and power densities of anode-free batteries via composite current collector innovation but, in a broader context, provide a new paradigm to pursue high-performance, high-safety, and flexible batteries.

Tri-anions regulated solvation structure in intrinsically nonflammable phosphate-based electrolytes for stable lithium metal batteries

The cycling instability and unsafety blocked the application of lithium metal batteries (LMB). Nonflammable solvents are hoped to improve the security of LMB; however, employing these solvents will irreversibly damage the cycling stability owing to incompatibility with Li metal. Herein, we regulated solvation structures in triethyl phosphate (TEP) through a simple Tri-anions strategy to achieve cycling stability and safety of LMB. Molecular dynamic simulation demonstrates that the solvation structure is well adjusted which can induce a powerful inorganic-rich solid electrolyte interface (SEI) to circumvent parasitic reactions between TEP solvents and Li anode as well as promote uniformly Li deposition. As a result, Li/LiNi0.8Co0.1Mn0.1O2 (NCM 811) cell has a capacity retention of 98.6 % after 300 cycles and Li/LiFePO4 (LFP) cell retains 75 % after 700 cycles. The novel electrolyte is expected to offer a promising approach for improving high safety and high-electrochemical-performance LMB.

Rational design of polymer-based insulating scaffolds for high-capacity lithium metal batteries

Lithium metal is a promising anode material for next-generation high-energy–density secondary batteries. However, the uncontrolled growth of Li dendrites leads to infinite volume expansion and poor cycling stability. Herein, we propose a designable insulating polydopamine (PDA)-coated porous polytetrafluoroethylene (PTFE) scaffold. A porous PTFE (pPTFE) scaffold with micron-sized pores was fabricated, which provided bottom-up Li deposition owing to its insulating nature. Furthermore, the PDA-coated porous PTFE (PDA-pPTFE) scaffold provided internal space for Li growth and homogenized the Li-ion flux with abundant polar functional groups in the PDA, enabling “bottom-up” Li deposition within the scaffold without dendrite growth. This uniquely designed scaffold demonstrated excellent performance in half and symmetric cells with a small voltage hysteresis and dendrite-free Li plating. Moreover, when coupled with high-loading NCM cathodes (∼4 mA h cm−2), the PDA-pPTFE-based full cells exhibited stable cycling and rate performance, even with a low NP ratio of 1.0 at a rate of 1/3C, and exhibited a high energy density of 801 W h L−1. These results indicated the potential of the PDA-pPTFE scaffold as an anode material for highly stable next-generation rechargeable batteries.

In situ constructing fluorine/nitrogen-enriched interface on highly lithiophilic carbon fiber/MXene/ZnS skeleton for stable lithium anodes

Metallic lithium (Li) is an excellent electrode material for high-energy-density batteries; however, the continuous growth of Li dendrites and the poor deposited volume consistency of Li severely influence the stability of Li anodes. Herein, a LiF-Li3N/LiNxOy-enriched SEI is prepared in situ using a strongly lithiophilic 3D carbon fiber/MXene/ZnS (CMZ) skeleton. Multiscale in situ and ex situ characterizations reveal the mechanisms for Li nucleation and growth on the CMZ skeleton, proving that Li grows tightly over CMZ fibers. This behaviour is attributed to the CMZ skeleton, which provides abundant atomic-level active sites for the uniform and dense nucleation of Li. Electrochemical tests confirm that SEI enriched with LiF-Li3N/LiNxOy can effectively improve Li deposition kinetics, ensure uniform mass transfer and rapid migration of lithium ions in the SEI, and guarantee uniform growth of Li. Consequently, a half cell with a Li-CMZ electrode delivers a high Coulombic efficiency (99.83 %), an ultralong cycling life (17,860 h), and an excellent rate performance (30 mA cm−2). Moreover, full cells consisting of a Li-CMZ anode and different cathodes exhibit superior cycling stabilities. For Li-CMZ ‖ LiFePO4 pouch cell, 84 % capacity is maintained after 300 cycles at 1 C.

Revisiting porous foam Cu host based Li metal anode: The roles of lithiophilicity and hierarchical structure of three-dimensional framework

Lithium (Li) metal anode (LMA) is one of the most promising anodes for high energy density batteries. However, its practical application is impeded by notorious dendrite growth and huge volume expansion. Although the three-dimensional (3D) host can enhance the cycling stability of LMA, further improvements are still necessary to address the key factors limiting Li plating/stripping behavior. Herein, porous copper (Cu) foam (CF) is thermally infiltrated with molten Li-rich Li-zinc (Li-Zn) binary alloy (CFLZ) with variable Li/Zn atomic ratio. In this process, the LiZn intermetallic compound phase self-assembles into a network of mixed electron/ion conductors that are distributed within the metallic Li phase matrix and this network acts as a sublevel skeleton architecture in the pores of CF, providing a more efficient and structured framework for the material. The as-prepared CFLZ composite anodes are systematically investigated to emphasize the roles of the tunable lithiophilicity and hierarchical structure of the frameworks. Meanwhile, a thin layer of Cu-Zn alloy with strong lithiophilicity covers the CF scaffold itself. The CFLZ with high Zn content facilitates uniform Li nucleation and deposition, thereby effectively suppressing Li dendrite growth and volume fluctuation. Consequently, the hierarchical and lithiophilic framework shows low Li nucleation overpotential and highly stable Coulombic efficiency (CE) for 200 cycles in conventional carbonate based electrolyte. The full cell coupled with LiFePO4 (LFP) cathode demonstrates high cycle stability and rate performance. This work provides valuable insights into the design of advanced dendrite-free 3D LMA toward practical application.

Boosted Li+ transport ensured by high-entropy Prussian blue analogues with tuned PF6− adsorption for stable Li metal anode

The inhomogeneous lithium metal (Li) deposition and low lithium ion (Li+) mobility lead to the formation and growth of Li dendrites, which impede the desirable performance of Li metal batteries (LMBs) with high energy density in widely practical applications. Herein, a high-entropy MnCoNiCuZn-Prussian blue analogue (HE-PBA) is utilized to modify the commercial polypropylene separator (PP@HE-PBA), which will form an artificial protective layer on the surface of Li. The polar –CN groups of HE-PBA can enhance the wettability of PP to the electrolyte, while the movement of PF6− anions are flexibly tuned by the appropriate absorption ability and synergistic effect of multiple metal ions in HE-PBA. A high Li+ transference number of 0.69 is achieved, which can relieve the Li+ concentration polarization, regulate the Li+ flow, and realize the uniform Li deposition. With PP@HE-PBA, the Li||Li symmetric cells display durability up to 600 h in the ester-based electrolyte at 1 mA cm−2 for 1 mAh cm−2. Also, the PP@HE-PBA exhibits great potential in LMBs, where the Li4Ti5O12 (LTO) ||Li and sulfated polyacrylonitrile (S-PAN) ||Li batteries deliver superior cycling performance to those without PP@HE-PBA.

Defect-Mediated Faceted Lithium Nucleation on Carbon Composite Substrates.

The formation of uniform, nondendritic seeds is essential to realizing dense lithium (Li) metal anodes and long-life batteries. Here, we discover that faceted Li seeds with a hexagonal shape can be uniformly grown on carbon-polymer composite films. Our investigation reveals the critical role of carbon defects in serving as the nucleation sites for their formation. Tuning the density and spatial distribution of defects enables the optimization of conditions for faceted seed growth. Raman spectral results confirm that lithium nucleation indeed starts at the defect sites. The uniformly distributed crystalline seeds facilitate low-porosity Li deposition, effectively reducing Li pulverization during cycling and unlocking the fast-charging ability of Li metal batteries. At a 1 C rate, full cells using LiNi0.8Mn0.1Co0.1O2 cathode (4.5 mA h cm-2) paired with a lithium anode grown on carbon composite films achieve a 313% improvement in cycle life compared to baseline cells. Polymer composites with carbonaceous materials rich in defects are scalable, low-cost substrates for high-rate, high-energy-density batteries.