A Multifunctional Zwitterion Electrolyte Additive for Highly Reversible Zinc Metal Anode.

Although zinc metal anode is promising for zinc-ion batteries (ZIBs) owing to high energy density, its reversibility is significantly obstructed by uncontrolled dendrite growth and parasitic reactions. Optimizing electrolytes is a facile yet effective method to simultaneously address these issues. Herein, 2-(N-morpholino)ethanesulfonic acid (MES), a pH buffer as novel additive, is initially introduced into conventional ZnSO4 electrolyte to ensure a dendrite-free zinc anode surface, enabling a stable Zn/electrolyte interface, which is achieved by controlling the solvated sheath through H2O poor electric double layer (EDL) derived from zwitterionic groups. Moreover, this zwitterionic additive can balance localized H+ concentration of the electrolyte system, thus preventing parasitic reactions in damaging electrodes. DFT calculation proves that the MES additive has a strong affinity with Zn2+ and induces uniform deposition along (002) orientation. As a result, the Zn anode in MES-based electrolyte exhibits exceptional plating/stripping lifespan with 1600 h at 0.5 mA cm-2 (0.5 mAh cm-2) and 430 h at 5.0 mA cm-2 (5.0 mAh cm-2) while it maintains high coulombic efficiency of 99.8%. This work proposes an effective and facile approach for designing dendrite-free anode for future aqueous Zn-based storage devices.

Fluorine- and Acid-Free Strategy toward Scalable Fabrication of Two-Dimensional MXenes for Sodium-Ion Batteries.

MXenes are emerging 2D materials that have gained great attention because of their unique physical-chemical properties. However, the wide application of MXenes is prohibited by their high cost and environmentally harmful synthesis process. Here a fluoride- and acid-free physical vacuum distillation strategy is proposed to directly synthesize a series of MXenes. Specifically, by introducing a low-boiling-point element into MAX and subsequently evaporating A elements via physical vacuum distillation, fluoride-free MXenes (Ti3C2Tx, Nb2CTx, Nb4C3Tx, Ta2CTx, Ti2NTx, Ti3CNTx, etc.) are fabricated. This is a green and one-step process without any acid/alkaline involved and with all reactions inside a vacuum tube furnace, avoiding any contamination to external environments. Besides, the synthetic temperature is controlled to regulate the layered structures and specific surface areas of MXenes. Accordingly, the synthesized Ti3C2Tx MXene exhibits improved sodium storage performance. This method may provide an alternative for the scalable production of MXenes and other 2D materials.

Design of Robust, Lithiophilic, and Flexible Inorganic-Polymer Protective Layer by Separator Engineering Enables Dendrite-Free Lithium Metal Batteries with LiNi0.8 Mn0.1 Co0.1 O2 Cathode.

As a promising candidate for the high energy density cells, the practical application of lithium-metal batteries (LMBs) is still extremely hindered by the uncontrolled growth of lithium (Li) dendrites. Herein, a facile strategy is developed that enables dendrite-free Li deposition by coating highly-lithiophilic amorphous SiO microparticles combined with high-binding polyacrylate acid (SiO@PAA) on polyethylene separators. A lithiated SiO and PAA (lithiated-SiO/PAA) protective layer with synergistic flexible and robust features is formed on the Li metal anode via the in situ reaction to offer outstanding interfacial stability during long-term cycles. By suppressing the formation of dead Li and random Li deposition, reducing the side reaction, and buffering the volume changes during the lithium deposition and dissolution, such a protective layer realizes a dendrite-free morphology of Li metal anode. Furthermore, sufficient ionic conductivity, uniform lithium-ion flux, and interface adaptability is guaranteed by the lithiated-SiO and Li polyacrylate acid. As a result, Li metal anodes display significantly enhanced cycling stability and coulombic efficiency in Li||Li and Cu||Li cells. When the composite separator is applied in a full cell with a carbonate-based electrolyte and LiNi0.8 Mn0.1 Co0.1 O2 cathode, it exhibits three times longer lifespan than control cell at current density of 5 C.

Room-Temperature Liquid Metal Confined in MXene Paper as a Flexible, Freestanding, and Binder-Free Anode for Next-Generation Lithium-Ion Batteries.

Exploring flexible lithium-ion batteries is required with the ever-increasing demand for wearable and portable electronic devices. Selecting a flexible conductive substrate accompanying with closely coupled active materials is the key point. Here, a lightweight, flexible, and freestanding MXene/liquid metal paper is fabricated by confining 3 °C GaInSnZn liquid metal in the matrix of MXene paper without any binder or conductive additive. When used as anode for lithium-ion cells, it can deliver a high discharge capacity of 638.79 mAh g-1 at 20 mA g-1 . It also exhibits satisfactory rate capacities, with discharge capacities of 507.42, 483.33, 480.22, 452.30, and 404.47 mAh g-1 at 50, 100, 200, 500, and 1000 mA g-1 , respectively. The cycling performance is obviously improved by slightly reducing the charge-discharge voltage range. The composite paper also has better electrochemical performance than liquid metal coated Cu foil. This study proposes a novel flexible anode by a clever combination of MXene paper and low-melting point liquid metal, paving the way for next-generation lithium-ion batteries.

Ultrastable and High-Rate 2D Siloxene Anode Enabled by Covalent Organic Framework Engineering for Advanced Lithium-Ion Batteries.

Siloxene as a new type of 2D material has wide potential applications due to its special structure. Especially, as anode for lithium-ion batteries, siloxene shows promising prospect due to its small volume change and low diffusion pathway. However, the unstable solid electrolyte interphase and low electronic conductivity lead to the low Coulombic efficiency, poor rate capability, and limited cycling performance. To settle the problems, a thin porous covalent organic framework (COF) coating layer is designed by in situ growth on micro-sized siloxene. With the inherent ionic conductive and electrolyte compatible advantages of COF, the engineered siloxene demonstrates superior electrochemical performance with 96% capacity retention at 8 A g-1 for 1500 cycles.

One-Step, Vacuum-Assisted Construction of Micrometer-Sized Nanoporous Silicon Confined by Uniform Two-Dimensional N-Doped Carbon toward Advanced Li Ion and MXene-Based Li Metal Batteries.

With the advantages of a high theoretical capacity, proper working voltage, and abundant reserves, silicon (Si) is regarded as a promising anode for lithium-ion batteries. However, huge volume expansion and low electronic conductivity impede the commercialization of Si anodes. We devised a one-step, vacuum-assisted reactive carbon coating technique to controllably produce micrometer-sized nanoporous silicon confined by homogeneous N-doped carbon nanosheet frameworks (NPSi@NCNFs), achieved by the solid state reaction of a commercial bulk precursor and the subsequent evaporation of byproducts. The graphitization degree, C and N contents of the carbon shell, as well as the porosity of Si can be regulated by adjusting the synthetic conditions. A rational structure can mitigate volume expansion to maintain structural integrity, enhance electronic conductivity to facilitate charge transport, and serve as a protected layer to stabilize the solid electrolyte interphase. The NPSi@NCNF anode enables a stable cycling performance with 95.68% capacity retention for 4000 cycles at 5 A g-1. Furthermore, a flexible 2D/3D architecture is designed by conjugating NPSi@NCNFs with MXene. Lithiophilic NPSi@NCNFs homogenize Li nucleation and growth, evidenced by structural evolutions of MXene@NPSi@NCNF deposited Li. The application potential of NPSi@NCNFs and MXene@NPSi@NCNFs is estimated via assembling full cells with LiNi0.8Co0.1Mn0.1O2 and LiNi0.5Mn1.5O4 cathodes. This work offers a method for the rational design of alloy-based materials for advanced energy storage.

Highly Reversible Zn Metal Anodes Enabled by Freestanding, Lightweight, and Zincophilic MXene/Nanoporous Oxide Heterostructure Engineered Separator for Flexible Zn-MnO2 Batteries.

Aqueous zinc (Zn)-ion batteries are regarded as promising candidates for large-scale energy storage systems because of their high safety, low cost, and environmental benignity. However, the dendrite issue of Zn anode hinders their practical application. Herein, a freestanding, lightweight, and zincophilic MXene/nanoporous oxide heterostructure engineered separator is designed to stabilize a Zn metal anode. The nanoporous oxides prepared by a one-step vacuum distillation technique afford the advantages of large surface area, high porosity, and homogeneous porous structure. The zincophilic MXene@oxides layer can homogenize the electric field distribution, facilitate ion diffusion kinetics, reduce local current density, and promote even Zn ionic flux, which will regulate uniform Zn deposition and suppress side reactions. Accordingly, dendrite-free Zn anodes with stable cyclability are achieved for over 500 h at an ultrahigh area capacity of 10 mAh cm-2. Besides, flexible, long-lifespan, and high-rate N/S-doped three-dimensional MXene@MnO2||Zn full cells are constructed with the engineered separator. Moreover, this strategy can be successfully extended to lithium, sodium, potassium, and magnesium metal batteries, indicating that separator regulation is a universal approach to overcome the challenges of metal batteries.

Biofunctional hollow γ-MnO2 microspheres by a one-pot collagen-templated biomineralization route and their applications in lithium batteries.

γ-MnO2 nanomaterials play an essential role in the development of advanced electrochemical energy storage and conversion devices with versatile industrial applications. Herein, novel dandelion-like hollow microspheres of γ-MnO2 mesocrystals have been fabricated for the first time by a one-pot biomineralization route. Recombinant collagen with unique rod-like structure has been demonstrated as a robust template to tune the morphologies of γ-MnO2 mesocrystals, and a very low concentration of collagen can alter the nanostructures of γ-MnO2 from nanorods to microspheres. The as-prepared γ-MnO2 mesocrystals formed well-ordered hollow microspheres composed of delicate nanoneedle-like units. Among all the reported γ-MnO2 with various nanostructures, the γ-MnO2 microspheres showed the most prowess to maintain high discharge capacities after 100+ cycles. The superior electrochemical performance of γ-MnO2 likely results from its unique hierarchical micro-nano structure. Notably, the γ-MnO2 mesocrystals display high biocompatibility and cellular activity. Collagen plays a key dual role in mediating the morphology as well as endowing the biofunction of the γ-MnO2 mesocrystals. This environmentally friendly biomineralization approach using rod-like collagen as the template, provides unprecedented opportunity for the production of novel nanostructured metal oxides with superior biocompatibility and electrochemical performance, which have great potential in advanced implantable and wearable health-care electronic devices.

Scalable and Controllable Synthesis of Interface-Engineered Nanoporous Host for Dendrite-Free and High Rate Zinc Metal Batteries.

Rechargeable zinc (Zn)-ion batteries are regarded as highly prospective candidates for next-generation renewable and safe energy storage systems. However, the uncontrolled dendrite growth of the Zn anode impedes their practical application. Here, a scalable and controllable approach is developed for converting commercial titanium (Ti) foil to 3D porous Ti, which retains good resistance to corrosion, high electrical conductivity, and excellent mechanical properties. Benefiting from a spontaneous ultrathin zincophilic titanium dioxide (TiO2) interfacial layer and continuous 3D structure, the 3D porous Ti can act as an effective host to achieve a 3D Ti/Zn metal anode. By ensuring homogeneous nucleation, uniform current distribution, and volume change accommodation, the dendritic growth of 3D Ti/Zn metal anode is effectively inhibited with stable Zn plating/stripping up to 2000 h with low polarization. When conjugated with a 3D sulfur-doped Ti3C2Tx MXene@MnO2 nanotube cathode, a high rate and stable Zn cell is achieved with 95.46% capacity retention after 500 cycles at a high rate of 5 A g-1. This work may also be interesting for researches in porous metals and other battery systems.

High-Safety and Dendrite-Free Lithium Metal Batteries Enabled by Building a Stable Interface in a Nonflammable Medium-Concentration Phosphate Electrolyte.

Lithium metal anodes are promising for their high energy density and low working potential. However, high reactivity and dendrite growth of lithium metal lead to serious safety issues. Lithium dendrite may form "dead lithium" or pierce the separator, which will cause low efficiency and short-circuit inside the battery. A nonflammable phosphate-based electrolyte can effectively solve the flammability problem. Also, it shows poor compatibility with lithium metal anodes, resulting in an unstable solid electrolyte interface (SEI), which leads to dendrite growth and poor electrochemical performance. In this study, trimethyl phosphate is used to ensure the safety of lithium metal batteries. By adjusting the concentration of lithium salt and introducing fluoroethylene carbonate, a stable SEI layer is formed on the surface of the lithium metal anode and dendrite growth of the lithium metal anode is inhibited. Lithium metal batteries with a modified electrolyte achieved stable electrochemical plating/stripping, and the full cell has 93.4% capacity left and the coulombic efficiency is nearly 100%. In addition, the modified electrolyte can also enable reversible intercalation and de-intercalation of Li+ in the commercial graphite anode. This work may provide an alternative direction for the development of lithium metal batteries with high safety and high energy density.

Rational Design of Sulfur-Doped Three-Dimensional Ti3C2Tx MXene/ZnS Heterostructure as Multifunctional Protective Layer for Dendrite-Free Zinc-Ion Batteries.

Owing to its high theoretical capacity, appropriate working potential, abundant resource, intrinsic safety, and low cost, zinc (Zn) metal is regarded as one of the most promising anode candidates for aqueous batteries. However, the hazards caused by dendrite growth and side reactions impede its practical applications. Herein, to solve these problems, a protective heterogeneous layer composed of electronic conductive sulfur-doped three-dimensional (3D) MXene and ionic conductive ZnS on Zn anode is designed and constructed. The sulfur doping and the creation of a 3D structure on MXene are simultaneously achieved during the generation of ZnS. The sulfur-doped 3D MXene can effectively homogenize distribution of electric field, decrease local current density, and alleviate volume change. The ZnS can inhibit side reactions, promote uniform Zn2+ distribution, and accelerate Zn2+ migration. Consequently, a stable and dendrite-free Zn anode is achieved with notable cycling stability up to 1600 h and rate performance. The relationship between structure of protective layer and performance of Zn anode is also probed. With the protected Zn anode and freestanding sulfur-doped 3D MXene@MnO2 cathode, a high-energy, long cycling life, and high-rate full cell is obtained. This work may provide a direction for the design of practical Zn anodes and other metal-based battery systems.

High-Safety and High-Voltage Lithium Metal Batteries Enabled by a Nonflammable Ether-Based Electrolyte with Phosphazene as a Cosolvent.

The high reactivity between lithium metal and traditional carbonate electrolytes is a great obstacle to realize the long-term cycling ability of lithium metal batteries. Ether-based electrolytes have good stability toward lithium metal anodes. However, the oxidation stability of ether-based electrolytes is generally lower than 4 V, which limits the application of high-voltage (>4 V) cathodes and restricts the energy density. The high flammability of ether is another key issue that hinders the commercialization of ether-based electrolytes. To address these issues, herein, we report a high-voltage, nonflammable ether-based electrolyte with F-, N-, and P-rich hexafluorocyclotriphosphazene (HFPN) as a cosolvent. HFPN can not only act as a highly efficient flame-retarding agent but also form a dense and homogeneous solid electrolyte interphase (SEI) layer rich in LiF and Li3N on the lithium metal anode, which stabilizes the lithium/electrolyte interface and inhibits the formation of lithium dendrites. Moreover, the HFPN-based electrolyte has a wider potential window than 4 V. As a result, with this electrolyte, high-voltage lithium metal batteries exhibit a capacity retention of ∼95% after 100 cycles. This study may provide a new pathway for developing safe, high-energy, and dendrite-free lithium metal batteries.

Porous lithium cobalt oxide fabricated from metal-organic frameworks as a high-rate cathode for lithium-ion batteries.

Porous materials have many applications, such as energy storage, as catalysts and adsorption etc. Nevertheless, facile synthesis of porous materials remains a challenge. In this work, porous lithium cobalt oxide (LiCoO2) is fabricated directly from Co-based metal-organic frameworks (MOFs, ZIF-67) and lithium salt via a facile solid state annealing approach. The temperature affect on the microstructure of LiCoO2 is also investigated. The as-prepared LiCoO2 shows a uniform porous structure. As a cathode for a lithium-ion battery (LIB), the LiCoO2 delivers excellent stability and superior rate capability. The as-prepared porous LiCoO2 delivers a reversible capacity of 106.5 mA h g-1 at 2C and with stable capacity retention of 96.4% even after 100 cycles. This work may provide an alternative pathway for the preparation of porous materials with broader applications.

Controllable Phosphorylation Strategy for Free-Standing Phosphorus/Nitrogen Cofunctionalized Porous Carbon Monoliths as High-Performance Potassium Ion Battery Anodes.

A hard carbon material with free-standing porous structure and high contents of heteroatom functional groups is considered to be a potential anode for potassium-ion batteries (PIBs). Herein, a free-standing phosphorus/nitrogen cofunctionalized porous carbon monolith (denoted as PN-PCM) anode for PIBs is successfully fabricated via a supercritical CO2 foaming technology, followed by amidoximation, phosphorylation, and thermal treatment. Thanks to the synergistic effect of a three-dimensional macroporous open structure and high P/N contents of 6.19/5.74 at%, the PN-PCM anode delivers an excellent reversible specific capacity (396 mA h g-1 at 0.1 A g-1 after 300 cycles) with high initial Coulombic efficiency (63.6%), a great rate performance (168 mA h g-1 at 5 A g-1), and an ultralong cycling stability (218 mA h g-1 at 1 A g-1 after 3000 cycles). Theoretical calculations clarify that in a P/N cofunctionalized carbon, the P-C bonds devote more to enhancing the potassium storage via adsorption and improving electronic conductivity of carbon, while P-O bonds contribute more to enlarging the interlayer distance of carbon and reducing the ion diffusion barrier.

Two-Dimensional Silicon/Carbon from Commercial Alloy and CO2 for Lithium Storage and Flexible Ti3C2Tx MXene-Based Lithium-Metal Batteries.

Silicon has been considered as the most promising anode candidate for next-generation lithium-ion batteries. However, the fast capacity decay caused by huge volume expansion and low electronic conductivity limit the electrochemical performance. Herein, atomic distributed, air-stable, layer-by-layer-assembled Si/C (L-Si/C) is designed and in situ constructed from commercial micron-sized layered CaSi2 alloy with the greenhouse gas CO2. The inner structure of Si as well as the content and graphitization of C can be regulated by simply adjusting the reaction conditions. The rationally designed layered structure can enhance electronic conductivity and mitigate volume change without disrupting the carbon layer or destroying the solid electrolyte interface. Moreover, the single-layer Si and C can enhance lithium-ion transport in active materials. With these advantages, L-Si/C anode delivers an 82.85% capacity retention even after 3200 cycles and superior rate performance. The battery-capacitance dual-model mechanism is certified via quantitative kinetics measurement. Besides, the self-standing architecture is designed via assembling L-Si/C and MXene. Lithiophilic L-Si/C can guide homogeneous Li deposition with alleviated volume change. With the MXene/L-Si/C host for lithium-metal batteries, an ultralong life span up to 500 h in a carbonate-based electrolyte is achieved. A full cell with a high-energy 5 V LiNi0.5Mn1.5O4 cathode is constructed to verify the practicality of L-Si/C and MXene/L-Si/C. The rational design of a special layer structure may propose a strategy for other materials and energy storage systems.

Flexible and Freestanding Silicon/MXene Composite Papers for High-Performance Lithium-Ion Batteries.

Silicon has been developed as the exceptionally desirable anode candidate for lithium-ion batteries (LIBs), attributing to its highest theoretical capacity, low working potential, and abundant resource. However, large volume expansion and poor conductivity hinder its practical application. Herein, we fabricate flexible, freestanding, and binder-free silicon/MXene composite papers directly as anodes for LIBs. The Silicon/MXene composite papers are synthesized via covalently anchoring silicon nanospheres on the highly conductive networks based on MXene sheets by vacuum filtration. This unique architecture can accommodate large volume expansion, enhance conductivity of composites, prevent restacking of MXene sheets, offer additional active sites, and facilitate efficient ion transport, which exhibits superior electrochemical performance with a high capacity of 2118 mAh·g-1 at 200 mA·g-1 current density after 100 cycles, a steady cycling ability of 1672 mAh·g-1 at 1000 mA·g-1 after 200 cycles, and a rate performance of 890 mAh·g-1 at 5000 mA·g-1. This work may shed lights on the development of silicon-based anodes for LIBs.

Nonflammable Fluorinated Carbonate Electrolyte with High Salt-to-Solvent Ratios Enables Stable Silicon-Based Anode for Next-Generation Lithium-Ion Batteries.

High energy density and safety are two key factors for the development of next-generation lithium-ion batteries. Recently, silicon (Si) has attracted tremendous interest owing to its high theoretical capacity. However, the fast capacity decay triggered by huge volume change restricts its practical application. Moreover, higher energy density brings about more serious safety issues. To solve these problems, here we propose a safer high salt-to-solvent electrolyte that consisted of nonflammable mixture solvents of di-2,2,2-trifluoroethyl carbonate and fluoroethylene carbonate. It is revealed that this electrolyte could not only enhance the cycling stability toward the silicon nanoparticle (SiNPs) anode but also solve the safety hazards. A high initial reversible capacity of 2644 mAh g-1 and a low capacity fading rate (only 0.064% per cycle) after 300 cycles are delivered. The performance enhancement mechanism is further explored by electrochemical impedance spectroscopy, Fourier transform infrared, and scanning electron microscopy. This study may shed an inspiring light on the development of next-generation high-energy-density batteries.

Flexible and Free-Standing Ti3C2Tx MXene@Zn Paper for Dendrite-Free Aqueous Zinc Metal Batteries and Nonaqueous Lithium Metal Batteries.

Dendrite growth of metal anodes is one of the key hindrances for both secondary aqueous metal batteries and nonaqueous metal batteries. In this work, a freestanding Ti3C2Tx MXene@Zn paper is designed as both zinc metal anode and lithium metal anode host to address the issue. The binder-free Ti3C2Tx MXene@Zn paper exhibits merits of good mechanical flexibility, high electronic conductivity, hydrophilicity, and lithiophilicity. The crystal growth mechanism of Zn metal on common Zn foil and Ti3C2Tx MXene@Zn composite is also studied. It is found that the Ti3C2Tx MXene@Zn paper can effectively suppress the dendrite growth of Zn, enabling reversible and fast Zn plating/stripping kinetics in an aqueous electrolyte. Moreover, the Ti3C2Tx MXene@Zn paper can be used as a 3D host for a lithium metal anode. In this host, Zn is utilized as a nucleation agent to suppress the Li dendrite growth. The freestanding Ti3C2Tx MXene@Zn@Li anode exhibits superior reversibility with high Coulombic efficiency (97.69% over 600 cycles at 1.0 mA cm-2) and low polarization compared with the Cu@Li anode. These findings may be useful for the design of dendrite-free metal-based energy storage systems.

Novel Method of Fabricating Free-Standing and Nitrogen-Doped 3D Hierarchically Porous Carbon Monoliths as Anodes for High-Performance Sodium-Ion Batteries by Supercritical CO2 Foaming.

Sodium-ion batteries (SIBs), a promising candidate for large-scale energy storage systems, have recently attracted significant attention because of the low cost and high availability of the sodium resource. Hard carbon with a free-standing structure and plenty of active sites is considered to be the most potential anode material for SIBs. However, keeping a balance between the excellent performance and low cost for the large-scale commercial production of carbon anodes is still a great difficulty. Herein, a free-standing nitrogen-doped 3D hierarchically porous carbon monolith (denoted as 3DHPCM) anode for SIBs is successfully fabricated via a novel supercritical CO2 foaming technology and thermal treatment. Thanks to the tunable macro-meso-microporous and disordered structures, the 3DHPCM exhibits a high reversible specific capacity (281 mA h g-1 after 300 cycles at 50 mA g-1), superior rate performance (67 mA h g-1 at 10 A g-1), and excellent long-term cycling stability (175 mA h g-1 after 3000 cycles at 500 mA g-1). Remarkably, the 3DHPCM with such a high performance is fabricated via an environmentally friendly strategy from low-cost polyacrylonitrile and polymethyl methacrylate. Therefore, the strategy has great potential in practical application for fabricating high-performance hard carbon anodes and other composite electrodes for SIBs and more energy storage devices.

Scalable and Physical Synthesis of 2D Silicon from Bulk Layered Alloy for Lithium-Ion Batteries and Lithium Metal Batteries.

Owing to its distinctive structure and properties, 2D silicon (2DSi) has been widely applied in hydrogen storage, sensors, electronic device, catalysis, electrochemical energy storage, etc. However, scalable and low-cost fabrication of high-quality 2DSi remains a great challenge. In this work, a physical vacuum distillation method is designed to obtain high-quality 2DSi from a bulk layered calcium-silicon alloy. With this method, the lower boiling point calcium metal is evaporated to construct 2DSi and can be further recycled. The effect of vacuum conditions on morphology, components, and electrochemical properties is further explored. As an anode for lithium-ion batteries, the 2DSi delivers a stable cyclability of 835 mAh g-1 after 3000 cycles at 5000 mA g-1 (0.003025% capacity decay per cycle). The electrochemical performance enhancing mechanism is also probed. In addition, a 2D/2D flexible and binder-free paper by combining 2DSi with 2D MXene is constructed. As a lithiophilic nuclear agent for lithium metal anodes, the 2DSi can efficiently suppress the Li dendrite growth and reduce nucleation barriers, achieving a high Coulombic efficiency (98% at 1 mA cm-2, 97% at 2 mA cm-2) around 600 cycles and a long lifespan of 1000 h. The crystal growth difference of lithium metal on Cu foil and 2DSi is studied. This work may provide a pathway for green, low-cost, and scalable synthesis of 2D materials.