An Autotransferable g‐C3N4 Li+‐Modulating Layer toward Stable Lithium Anodes

Commercial deployment of lithium anodes has been severely impeded by the poor battery safety, unsatisfying cycling lifespan, and efficiency. Recently, building artificial interfacial layers over a lithium anode was regarded as an effective strategy to stabilize the electrode. However, the fabrications reported so far have mostly been conducted directly upon lithium foil, often requiring stringent reaction conditions with indispensable inert environment protection and highly specialized reagents due to the high reactivity of metallic lithium. Besides, the uneven lithium‐ion flux across the lithium surface should be more powerfully tailored via mighty interfacial layer materials. Herein, g‐C₃N₄ is employed as a Li⁺‐modulating material and a brand‐new autotransferable strategy to fabricate this interfacial layer for Li anodes without any inert atmosphere protection and limitation of chemical regents is developed. The g‐C₃N₄ film is filtrated on the separator in air using a common alcohol solution and then perfectly autotransferred to the lithium surface by electrolyte wetting during normal cell assembly. The abundant nitrogen species within g‐C₃N₄ nanosheets can form transient Li? N bonds to powerfully stabilize the lithium‐ion flux and thus enable a CE over 99% for 900 cycles and smooth deposition at high current densities and capacities, surpassing most previous works.     

Hierarchically Nanoporous 3D Assembly Composed of Functionalized Onion‐Like Graphitic Carbon Nanospheres for Anode‐Minimized Li Metal Batteries

Despite the recent attention for Li metal anode (LMA) with high theoretical specific capacity of ≈ 3860 mA h g^?1, it suffers from not enough practical energy densities and safety concerns originating from the excessive metal load, which is essential to compensate for the loss of Li sources resulting from their poor coulombic efficiencies (CEs). Therefore, the development of high‐performance LMA is needed to realize anode‐minimized Li metal batteries (LMBs). In this study, high‐performance LMAs are produced by introducing a hierarchically nanoporous assembly (HNA) composed of functionalized onion‐like graphitic carbon building blocks, several nanometers in diameter, as a catalytic scaffold for Li‐metal storage. The HNA‐based electrodes lead to a high Li ion concentration in the nanoporous structure, showing a high CE of ≈ 99.1%, high rate capability of 12 mA cm^?2, and a stable cycling behavior of more than 750 cycles. In addition, anode‐minimized LMBs are achieved using a HNA that has limited Li content ( ≈ 0.13 mg cm^?2), corresponding to 6.5% of the cathode material (commercial NCM622 ( ≈ 2 mg cm^?2)). The LMBs demonstrate a feasible electrochemical performance with high energy and power densities of ≈ 510 Wh kg_electrode^?1 and ≈ 2760 W kg_electrode^?1, respectively, for more than 100 cycles.     

Early Lithium Plating Behavior in Confined Nanospace of 3D Lithiophilic Carbon Matrix for Stable Solid‐State Lithium Metal Batteries

Considerable efforts are devoted to relieve the critical lithium dendritic and volume change problems in the lithium metal anode. Constructing uniform Li⁺ distribution and lithium “host” are shown to be the most promising strategies to drive practical lithium metal anode development. Herein, a uniform Li nucleation/growth behavior in a confined nanospace is verified by constructing vertical graphene on a 3D commercial copper mesh. The difference of solid‐electrolyte interphase (SEI) composition and lithium growth behavior in the confined nanospace is further demonstrated by in‐depth X‐ray photoelectron spectrometer (XPS) and line‐scan energy dispersive X‐ray spectroscopic (EDS) methods. As a result, a high Columbic efficiency of 97% beyond 250 cycles at a current density of 2 mA cm^?2 and a prolonged lifespan of symmetrical cell (500 cycles at 5 mA cm^?2) can be easily achieved. More meaningfully, the solid‐state lithium metal cell paired with the composite lithium anode and LiNi_0.5Co_0.2Mn_0.3O₂ (NCM) as the cathode also demonstrate reduced polarization and extended cycle. The present confined nanospace–derived hybrid anode can further promote the development of future all solid‐state lithium metal batteries.     

A 3D and Stable Lithium Anode for High‐Performance Lithium–Iodine Batteries

Lithium metal is considered as the most promising anode material due to its high theoretical specific capacity and the low electrochemical reduction potential. However, severe dendrite problems have to be addressed for fabricating stable and rechargeable batteries (e.g., lithium–iodine batteries). To fabricate a high‐performance lithium–iodine (Li–I₂) battery, a 3D stable lithium metal anode is prepared by loading of molten lithium on carbon cloth doped with nitrogen and phosphorous. Experimental observations and theoretical calculation reveal that the N,P codoping greatly improves the lithiophilicity of the carbon cloth, which not only enables the uniform loading of molten lithium but also facilitates reversible lithium stripping and plating. Dendrites formation can thus be significantly suppressed at a 3D lithium electrode, leading to stable voltage profiles over 600 h at a current density of 3 mA cm^?2. A fuel cell with such an electrode and a lithium–iodine cathode shows impressive long‐term stability with a capacity retention of around 100% over 4000 cycles and enhanced high‐rate capability. These results demonstrate the promising applications of 3D stable lithium metal anodes in next‐generation rechargeable batteries.     

Graphene Aerogels with Anchored Sub‐Micrometer Mulberry‐Like ZnO Particles for High‐Rate and Long‐Cycle Anode Materials in Lithium Ion Batteries

Graphene aerogels (GAs) anchoring hierarchical, mulberry‐like ZnO particles are fabricated in situ using a one‐step solvothermal reaction. The resulting composites can function as anodes in lithium ion batteries, where they exhibit a high capacity and cyclic stability. The reversible capacities obtained are 365, 320, and 230 mA h g^?1 at current densities of 1, 2, and 10 A g^?1. Their high reversible capacity is 445 mA h g^?1 at a current density of 1.6 A g^?1; this value is maintained even after the 500th cycle, The excellent electrochemical performance is attributed to strong oxygen bridges between ZnO and graphene, where C–O–Zn linkages provide a good pathway for electron transport during charge/discharge cycles. Additionally, the hierarchical structure of the ZnO microballs suppresses stacking among the graphene layers, allowing the GAs to accelerate the transport of lithium ions. Furthermore, the GA framework enhances the electrical conductivity and buffer any volume expansion.     

S‐Doped Carbon Fibers Uniformly Embedded with Ultrasmall TiO2 for Na+/Li+ Storage with High Capacity and Long‐Time Stability

Building a rechargeable battery with high capacity, high energy density, and long lifetime contributes to the development of novel energy storage devices in the future. Although carbon materials are very attractive anode materials for lithium‐ion batteries (LIBs), they present several deficiencies when used in sodium‐ion batteries (SIBs). The choice of an appropriate structural design and heteroatom doping are critical steps to improve the capacity and stability. Here, carbon‐based nanofibers are produced by sulfur doping and via the introduction of ultrasmall TiO₂ nanoparticles into the carbon fibers (CNF‐S@TiO₂). It is discovered that the introduction of TiO₂ into carbon nanofibers can significantly improve the specific surface area and microporous volume for carbon materials. The TiO₂ content is controlled to obtain CNF‐S@TiO₂‐5 to use as the anode material for SIBs/LIBs with enhanced electrochemical performance in Na⁺/Li⁺ storage. During the charge/discharge process, the S‐doping and the incorporation of TiO₂ nanoparticles into carbon fibers promote the insertion/extraction of the ions and enhance the capacity and cycle life. The capacity of CNF‐S@TiO₂‐5 can be maintained at ≈300 mAh g^?1 over 600 cycles at 2 A g^?1 in SIBs. Moreover, the capacity retention of such devices is 94%, showing high capacity and good stability.     

A Lightweight 3D Cu Nanowire Network with Phosphidation Gradient as Current Collector for High‐Density Nucleation and Stable Deposition of Lithium

Lithium metal anodes with high energy density are important for further development of next‐generation batteries. However, inhomogeneous Li deposition and dendrite growth hinder their practical utilization. 3D current collectors are widely investigated to suppress dendrite growth, but they usually occupy a large volume and increase the weight of the system, hence decreasing the energy density. Additionally, the nonuniform distribution of Li ions results in low utilization of the porous structure. A lightweight, 3D Cu nanowire current collector with a phosphidation gradient is reported to balance the lithiophilicity with conductivity of the electrode. The phosphide gradient with good lithiophilicity and high ionic conductivity enables dense nucleation of Li and its steady deposition in the porous structure, realizing a high pore utilization. Specifically, the homogenous deposition of Li leads to the formation of an oriented texture on the electrode surface at high capacities. A high mass loading (≈44 wt%) of Li with a capacity of 3 mAh cm^?2 and a high average Coulombic efficiency of 97.3% are achieved. A lifespan of 300 h in a symmetrical cell is obtained at 2 mA cm^?2, implying great potential to stabilize lithium metal.     

Microsphere‐Like SiO2/MXene Hybrid Material Enabling High Performance Anode for Lithium Ion Batteries

To address the non‐negligible volume expansion and the inherent poor electronic conductivity of silica (SiO₂) material, microsphere‐like SiO₂/MXene hybrid material is designed and successfully synthesized through the combination of the Stöber method and spray drying. The SiO₂ nanoparticles are firmly anchored on the laminated MXene by the bonding effect, which boosts the structural stability during the long‐term cycling process. The MXene matrix not only possesses high elasticity to buffer the volume variation of SiO₂ nanoparticles, but also promotes the transfer of electrons and lithium ions. Moreover, the microsphere wrapped with ductile MXene film reduces the specific surface area, relieves the side reactions, and enhances the coulombic efficiency. Therefore, superior electrochemical performance including high reversible capacity, outstanding cycle stability, high coulombic efficiency, especially in the first cycle, excellent rate capability as well as high areal capacity are acquired for SiO₂/MXene microspheres anode.     

A 3D Lithiophilic Mo2N‐Modified Carbon Nanofiber Architecture for Dendrite‐Free Lithium‐Metal Anodes in a Full Cell

The pursuit for high‐energy‐density batteries has inspired the resurgence of metallic lithium (Li) as a promising anode, yet its practical viability is restricted by the uncontrollable Li dendrite growth and huge volume changes during repeated cycling. Herein, a new 3D framework configured with Mo₂N‐mofidied carbon nanofiber (CNF) architecture is established as a Li host via a facile fabrication method. The lithiophilic Mo₂N acts as a homogeneously pre‐planted seed with ultralow Li nucleation overpotential, thus spatially guiding a uniform Li nucleation and deposition in the matrix. The conductive CNF skeleton effectively homogenizes the current distribution and Li‐ion flux, further suppressing Li‐dendrite formation. As a result, the 3D hybrid Mo₂N@CNF structure facilitates a dendrite‐free morphology with greatly alleviated volume expansion, delivering a significantly improved Coulombic efficiency of ≈99.2% over 150 cycles at 4 mA cm^?2. Symmetric cells with Mo₂N@CNF substrates stably operate over 1500 h at 6 mA cm^?2 for 6 mA h cm^?2. Furthermore, full cells paired with LiNi_0.8Co_0.1Mn_0.1O₂ (NMC811) cathodes in conventional carbonate electrolytes achieve a remarkable capacity retention of 90% over 150 cycles. This work sheds new light on the facile design of 3D lithiophilic hosts for dendrite‐free lithium‐metal anodes.     

Bimetal‐Organic‐Framework Derivation of Ball‐Cactus‐Like Ni‐Sn‐P@C‐CNT as Long‐Cycle Anode for Lithium Ion Battery

Metal phosphides are a new class of potential high‐capacity anodes for lithium ion batteries, but their short cycle life is the critical problem to hinder its practical application. A unique ball‐cactus‐like microsphere of carbon coated NiP₂/Ni₃Sn₄ with deep‐rooted carbon nanotubes (Ni‐Sn‐P@C‐CNT) is demonstrated in this work to solve this problem. Bimetal‐organic‐frameworks (BMOFs, Ni‐Sn‐BTC, BTC refers to 1,3,5‐benzenetricarboxylic acid) are formed by a two‐step uniform microwave‐assisted irradiation approach and used as the precursor to grow Ni‐Sn@C‐CNT, Ni‐Sn‐P@C‐CNT, yolk–shell Ni‐Sn@C, and Ni‐Sn‐P@C. The uniform carbon overlayer is formed by the decomposition of organic ligands from MOFs and small CNTs are deeply rooted in Ni‐Sn‐P@C microsphere due to the in situ catalysis effect of Ni‐Sn. Among these potential anode materials, the Ni‐Sn‐P@C‐CNT is found to be a promising anode with best electrochemical properties. It exhibits a large reversible capacity of 704 mA h g^?1 after 200 cycles at 100 mA g^?1 and excellent high‐rate cycling performance (a stable capacity of 504 mA h g^?1 retained after 800 cycles at 1 A g^?1). These good electrochemical properties are mainly ascribed to the unique 3D mesoporous structure design along with dual active components showing synergistic electrochemical activity within different voltage windows.     

Reactive Oxygen‐Doped 3D Interdigital Carbonaceous Materials for Li and Na Ion Batteries

Carbonaceous materials as anodes usually exhibit low capacity for lithium ion batteries (LIBs) and sodium ion batteries (SIBs). Oxygen‐doped carbonaceous materials have the potential of high capacity and super rate performance. However, up to now, the reported oxygen‐doped carbonaceous materials usually exhibit inferior electrochemical performance. To overcome this problem, a high reactive oxygen‐doped 3D interdigital porous carbonaceous material is designed and synthesized through epitaxial growth method and used as anodes for LIBs and SIBs. It delivers high reversible capacity, super rate performance, and long cycling stability (473 mA h g^?1after 500 cycles for LIBs and 223 mA h g^?1 after 1200 cycles for SIBs, respectively, at the current density of 1000 mA g^?1), with a capacity decay of 0.0214% per cycle for LIBs and 0.0155% per cycle for SIBs. The results demonstrate that constructing 3D interdigital porous structure with reactive oxygen functional groups can significantly enhance the electrochemical performance of oxygen‐doped carbonaceous material.     

Large‐Scale Modification of Commercial Copper Foil with Lithiophilic Metal Layer for Li Metal Battery

The application and development of lithium metal battery are severely restricted by the uncontrolled growth of lithium dendrite and poor cycle stability. Uniform lithium deposition is the core to solve these problems, but it is difficult to be achieved on commercial Cu collectors. In this work, a simple and commercially viable strategy is utilized for large‐scale preparation of a modified planar Cu collector with lithiophilic Ag nanoparticles by a simple substitution reaction. As a result, the Li metal shows a cobblestone‐like morphology with similar size and uniform distribution rather than Li dendrites. Interestingly, a high‐quality solid electrolyte interphase layer in egg shell‐like morphology with fast ion diffusion channels is formed on the interface of the collector, exhibiting good stability with long‐term cycles. Moreover, at the current density of 1 mA cm^?2 for 1 mAh cm^?2, the Ag modified planar Cu collector shows an ultralow nucleation overpotential (close to 0 mV) and a stable coulombic efficiency of 98.54% for more than 600 cycles as well as long lifespan beyond 900 h in a Li|Cu‐Ag@Li cell, indicating the ability of this method to realize stable Li metal batteries. Finally, full cells paired with LiNi_0.8Co_0.1Mn_0.1O₂ show superior rate performance and stability compared with those paired with Li foil.     

Penne‐Like MoS2/Carbon Nanocomposite as Anode for Sodium‐Ion‐Based Dual‐Ion Battery

The dual‐ion battery (DIB) system has attracted great attention owing to its merits of low cost, high energy, and environmental friendliness. However, the DIBs based on sodium‐ion electrolytes are seldom reported due to the lack of appropriate anode materials for reversible Na⁺ insertion/extraction. Herein, a new sodium‐ion based DIB named as MoS₂/C‐G DIB using penne‐like MoS₂/C nanotube as anode and expanded graphite as cathode is constructed and optimized for the first time. The hierarchical MoS₂/C nanotube provides expanded (002) interlayer spacing of 2H‐MoS₂, which facilitates fast Na⁺ insertion/extraction reaction kinetics, thus contributing to improved DIB performance. The MoS₂/C‐G DIB delivers a reversible capacity of 65 mA h g^?1 at 2 C in the voltage window of 1.0–4.0 V, with good cycling performance for 200 cycles and 85% capacity retention, indicating the feasibility of potential applications for sodium‐ion based DIBs.     

Ti3+ Self‐Doped Li4Ti5O12 Anchored on N‐Doped Carbon Nanofiber Arrays for Ultrafast Lithium‐Ion Storage

Omnibearing acceleration of charge/ion transfer in Li₄Ti₅O₁₂ (LTO) electrodes is of great significance to achieve advanced high‐rate anodes in lithium‐ion batteries. Here, a synergistic combination of hydrogenated LTO nanoparticles (H‐LTO) and N‐doped carbon fibers (NCFs) prepared by an electrodeposition‐atomic layer deposition method is reported. Binder‐free conductive NCFs skeletons are used as strong support for H‐LTO, in which Ti³⁺ is self‐doped along with oxygen vacancies in LTO lattice to realize enhanced intrinsic conductivity. Positive advantages including large surface area, boosted conductivity, and structural stability are obtained in the designed H‐LTO@NCF electrode, which is demonstrated with preeminent high‐rate capability (128 mAh g^?1 at 50 C) and long cycling life up to 10 000 cycles. The full battery assembled by H‐LTO@NCFs anode and LiFePO₄ cathode also exhibits outstanding electrochemical performance revealing an encouraging application prospect. This work further demonstrates the effectiveness of self‐doping of metal ions on reinforcing the high‐rate charge/discharge capability of batteries.     

Pine‐Needle‐Like Cu–Co Skeleton Composited with Li4Ti5O12 Forming Core–Branch Arrays for High‐Rate Lithium Ion Storage

High‐performance of lithium‐ion batteries (LIBs) rely largely on the scrupulous design of nanoarchitectures and smart hybridization of bespoke active materials. In this work, the pine‐needle‐like Cu–Co skeleton is reported to support highly active Li₄Ti₅O₁₂ (LTO) forming Cu–Co/LTO core–branch arrays via a united hydrothermal‐atomic layer deposition (ALD) method. ALD‐formed LTO layer is uniformly anchored on the pine‐needle‐like heterostructured Cu–Co backbone, which consists of branched Co nanowires (diameters in 20 nm) and Cu nanowires (250–300 nm) core. The designed Cu–Co/LTO core–branch arrays show combined advantages of large porosity, high electrical conductivity, and good adhesion. Due to the unique positive features, the Cu–Co/LTO electrodes are demonstrated with enhanced electrochemical performance including excellent high‐rate capacity (155 mAh g^?1 at 20 C) and noticeable long‐term cycles (144 mAh g^?1 at 20 C after 3000 cycles). Additionally, the full cell assembled with activated carbon positive electrode and Cu–Co/LTO negative electrode exhibits high power/energy densities (41.6 Wh kg^?1 at 7.5 kW kg^?1). The design protocol combining binder‐free characteristics and array configuration opens a new door for construction of advanced electrodes for application in high‐rate electrochemical energy storage.