2D Amorphous V2O5/Graphene Heterostructures for High‐Safety Aqueous Zn‐Ion Batteries with Unprecedented Capacity and Ultrahigh Rate Capability

Rechargeable aqueous zinc‐ion batteries (ZIBs) are appealing due to their high safety, zinc abundance, and low cost. However, developing suitable cathode materials remains a great challenge. Herein, a novel 2D heterostructure of ultrathin amorphous vanadium pentoxide uniformly grown on graphene (A‐V₂O₅/G) with a very short ion diffusion pathway, abundant active sites, high electrical conductivity, and exceptional structural stability, is demonstrated for highly reversible aqueous ZIBs (A‐V₂O₅/G‐ZIBs), coupling with unprecedented high capacity, rate capability, long‐term cyclability, and excellent safety. As a result, 2D A‐V₂O₅/G heterostructures for stacked ZIBs at 0.1 A g^?1 display an ultrahigh capacity of 489 mAh g^?1, outperforming all reported ZIBs, with an admirable rate capability of 123 mAh g^?1 even at 70 A g^?1. Furthermore, the new‐concept prototype planar miniaturized zinc‐ion microbatteries (A‐V₂O₅/G‐ZIMBs), demonstrate a high volumetric capacity of 20 mAh cm^?3 at 1 mA cm^?2, long cyclability; holding high capacity retention of 80% after 3500 cycles, and in‐series integration, demonstrative of great potential for highly‐safe microsized power sources. Therefore, the exploration of such 2D heterostructure materials with strong synergy is a reliable strategy for developing safe and high‐performance energy storage devices.     

Going beyond Intercalation Capacity of Aqueous Batteries by Exploiting Conversion Reactions of Mn and Zn electrodes for Energy‐Dense Applications

The recent trend in zinc (Zn) anode aqueous batteries has been to explore layered structures like manganese dioxides and vanadium oxides as Zn‐ion intercalation hosts. These structures, although novel, face limitations like their layered counterparts in lithium (Li)‐ion batteries, where the capacity is limited to the host's intercalation capacity. In this paper, a new strategy is proposed in enabling new generation of energy dense aqueous‐based batteries, where the conversion reactions of rock salt/spinel manganese oxides and carbon nanotube‐nested nanosized Zn electrodes are exploited to extract significantly higher capacity compared to intercalation systems. Accessing the conversion reactions allows to achieve high capacities of 750 mAh g^?1 (≈30 mAh cm^?2) from manganese oxide (MnO) and 810 mAh g^?1 (≈30 mAh cm^?2) from nanoscale Zn anodes, respectively. The high areal capacities help to attain unprecedented energy densities of 210 Wh per L‐cell and 320 Wh per kg‐total (398 Wh per kg‐active) from aqueous MnO|CNT‐Zn batteries, which allows an assessment of its viable use in a small‐scale automobile.     

Alkaline Polymer Membrane‐Based Ultrathin,Flexible, and High‐Performance Solid‐State Zn‐Air Battery

The increasing demand for portable and wearable electronics requires lightweight, thin, and highly flexible power sources, for example, flexible zinc‐air batteries (ZABs). The so‐far reported flexible ZAB devices mostly remain bulky, with a design consisting of two relatively thick substrates (e.g., carbon cloths and/or metal foams) and a gel electrolyte‐coated separator in between. Herein, an ultrathin (≈0.2 mm) solid‐state ZAB with high flexibility and performance is introduced by directly forming self‐standing active layers on each surface of an alkaline polymer membrane through an ink‐casting/hot‐pressing approach. A Fe/N‐doped 3D carbon with hierarchic pores and an interconnected network structure is used as cathode electrocatalyst, so that the backing gas‐diffusion layer (e.g., carbon cloth) can be abandoned. What is further, a microstructure‐modulating method to significantly increase the FeN₄ active sites for oxygen reduction reaction is developed, thus significantly boosting the performance of the ZAB. The assembled solid‐state ZAB manifests remarkable peak power density of 250 mW cm^?3 and high capacity of 150.4 mAh cm^?3 at 8.3 mA cm^?3, as well as excellent flexibility. The new design should provide valuable opportunity to the portable and wearable electronics.     

High‐Performance Reversible Aqueous Zn‐Ion Battery Based on Porous MnOx Nanorods Coated by MOF‐Derived N‐Doped Carbon

Rechargeable aqueous zinc‐ion batteries (ZIBs) have been emerging as potential large‐scale energy storage devices due to their high energy density, low cost, high safety, and environmental friendliness. However, the commonly used cathode materials in ZIBs exhibit poor electrochemical performance, such as significant capacity fading during long‐term cycling and poor performance at high current rates, which significantly hinder the further development of ZIBs. Herein, a new and highly reversible Mn‐based cathode material with porous framework and N‐doping (MnO_x@N‐C) is prepared through a metal–organic framework template strategy. Benefiting from the unique porous structure, conductive carbon network, and the synergetic effect of Zn²⁺ and Mn²⁺ in electrolyte, the MnO_x@N‐C shows excellent cycling stability, good rate performance, and high reversibility for aqueous ZIBs. Specifically, it exhibits high capacity of 305 mAh g^?1 after 600 cycles at 500 mA g^?1 and maintains achievable capacity of 100 mAh g^?1 at a quite high rate of 2000 mA g^?1 with long‐term cycling of up to 1600 cycles, which are superior to most reported ZIB cathode materials. Furthermore, insight into the Zn‐storage mechanism in MnO_x@N‐C is systematically studied and discussed via multiple analytical methods. This study opens new opportunities for designing low‐cost and high‐performance rechargeable aqueous ZIBs.     

Direct Growth of Flower‐Like δ‐MnO2 on Three‐Dimensional Graphene for High‐Performance Rechargeable Li‐O2 Batteries

A challenge still remains to develop high‐performance and cost‐effective air electrode for Li‐O₂ batteries with high capacity, enhanced rate capability and long cycle life (100 times or above) despite recent advances in this field. In this work, a new design of binder‐free air electrode composed of three‐dimensional (3D) graphene (G) and flower‐like δ‐MnO₂ (3D‐G‐MnO₂) has been proposed. In this design, graphene and δ‐MnO₂ grow directly on the skeleton of Ni foam that inherits the interconnected 3D scaffold of Ni foam. Li‐O₂ batteries with 3D‐G‐MnO₂ electrode can yield a high discharge capacity of 3660 mAh g^?1 at 0.083 mA cm^?2. The battery can sustain 132 cycles at a capacity of 492 mAh g^?1 (1000 mAh g_carbon ^?1) with low overpotentials under a high current density of 0.333 mA cm^?2. A high average energy density of 1350 Wh Kg^?1 is maintained over 110 cycles at this high current density. The excellent catalytic activity of 3D‐G‐MnO₂ makes it an attractive air electrode for high‐performance Li‐O₂ batteries.     

Hydrated Intercalation for High‐Performance Aqueous Zinc Ion Batteries

Aqueous zinc ion batteries (AZIBs) are steadily gaining attention based on their attractive merits regarding cost and safety. However, there are many obstacles to overcome, especially in terms of finding suitable cathode materials and elucidating their reaction mechanisms. Here, a mixed‐valence vanadium oxide, V₆O₁₃, that functions as a stable cathode material in mildly acidic aqueous electrolytes is reported. Paired with a zinc metal anode, this material exhibits performance metrics of 360 mAh g^?1 at 0.2 A g^?1, 92% capacity retention after 2000 cycles, and 145 mAh g^?1 at a current density of 24.0 A g^?1. A combination of experiments and density functional theory calculations suggests that hydrated intercalation, where water molecules are cointercalated with Zn ions upon discharge, accounts for the aforementioned electrochemical performance. This intercalation mechanism facilitates Zn ion diffusion throughout the host lattice and electrode–electrolyte interface via electrostatic shielding and concurrent structural stabilization. Through a correlation of experimental data and theoretical calculations, the promise of utilizing hydrated intercalation as a means to achieve high‐performance AZIBs is demonstrated.     

NaCa0.6V6O16·3H2O as an Ultra‐Stable Cathode for Zn‐Ion Batteries: The Roles of Pre‐Inserted Dual‐Cations and Structural Water in V3O8 Layer

Rechargeable aqueous batteries with Zn²⁺ as a working‐ion are promising candidates for grid‐scale energy storage because of their intrinsic safety, low‐cost, and high energy‐intensity. However, suitable cathode materials with excellent Zn²⁺‐storage cyclability must be found in order for Zinc‐ion batteries (ZIBs) to find practical applications. Herein, NaCa_0.6V₆O₁₆·3H₂O (NaCaVO) barnesite nanobelts are reported as an ultra‐stable ZIB cathode material. The original capacity reaches 347 mAh g^?1 at 0.1 A g^?1, and the capacity retention rate is 94% after 2000 cycles at 2 A g^?1 and 83% after 10 000 cycles at 5 A g^?1, respectively. Through a combined theoretical and experimental approach, it is discovered that the unique V₃O₈ layered structure in NaCaVO is energetically favorable for Zn²⁺ diffusion and the structural water situated between V₃O₈ layers promotes a fast charge‐transfer and bulk migration of Zn²⁺ by enlarging gallery spacing and providing more Zn‐ion storage sites. It is also found that Na⁺ and Ca²⁺ alternately suited in V₃O₈ layers are the essential stabilizers for the layered structure, which play a crucial role in retaining long‐term cycling stability.     

Graphene Wrapped FeSe2 Nano‐Microspheres with High Pseudocapacitive Contribution for Enhanced Na‐Ion Storage

Pseudocapacitance is a Faradaic process that involves surface or near surface redox reactions. Increasing the pseudocapacitive contribution is one of the most effective means to improve the rate performance of electrode materials. In this study, graphene oxide is used as a template to in situ synthesize burr globule‐like FeSe₂/graphene hybrid (B‐FeSe₂/G) using a facile one‐step hydrothermal method. Structural characterization demonstrates that graphene layers not only wrap the surfaces of FeSe₂ particles, but also stretch into the interior of these particles, as a result of which the unique nano‐microsphere structure is successfully established. When serving as anode material for Na‐ion batteries, B‐FeSe₂/G hybrid displays high electrochemical performance in the voltage range of 0.5–2.9 V. The B‐FeSe₂/G hybrid has high reversible capacity of 521.6 mAh·g^?1 at 1.0 A g^?1. Meanwhile, after 400 cycles, high discharge capacity of 496.3 mAh g^?1 is obtained at a rate of 2.5 A g^?1, with a high columbic efficiency of 96.6% and less than 1.0% loss of discharge capacity. Even at the ultrahigh rate of 10 A g^?1, a specific capacity of 316.8 mAh g^?1 can be achieved. Kinetic analyses reveal that the excellent performance of the B‐FeSe₂/G hybrid is largely attributed to the high pseudocapacitive contribution induced by the special nano‐micro structure.     

High‐Quality Graphene Microflower Design for High‐Performance Li–S and Al‐Ion Batteries

Poor quality and insufficient productivity are two main obstacles for the practical application of graphene in electrochemical energy storage. Here, high‐quality crumpled graphene microflower (GmF) for high‐performance electrodes is designed. The GmF possesses four advantages simultaneously: highly crystallized defect‐free graphene layers, low stacking degree, sub‐millimeter continuous surface, and large productivity with low cost. When utilized as carbon host for sulfur cathode, the GmF‐sulfur hybrid delivers decent areal capacities of 5.2 mAh cm^?2 at 0.1 C and 3.8 mAh cm^?2 at 0.5 C. When utilized as cathode of Al‐ion battery, the GmF affords a high capacity of 100 mAh g^?1 with 100% capacity retention after 5000 cycles and excellent rate capability from 0.1 to 20 A g^?1. This facile and large‐scale producible GmF represents a meaningful high‐quality graphene powder for practical energy storage technology. Meanwhile, this unique high‐quality graphene design provides an effective route to improve electrochemical properties of graphene‐based electrodes.     

Scaling Printable Zn–Ag2O Batteries for Integrated Electronics

Printed batteries are an emerging solution for integrated energy storage using low‐cost, high accuracy fabrication techniques. While several printed batteries have been previously shown, few have designed a battery that can be incorporated into an integrated device. Specifically, a fully printed battery with a small active electrode area (<1 cm²) achieving high areal capacities (>10 mAh cm^?2) at high current densities (1–10 mA cm^?2) has not been demonstrated, which represents the minimum form‐factor and performance requirements for many low‐power device applications. This work addresses these challenges by investigating the scaling limits of a fully printed Zn–Ag₂O battery and determining the electrochemical limitations for a mm²‐scale battery. Processed entirely in air, Zn–Ag₂O batteries are well suited for integration in typical semiconductor packaging flows compared to lithium‐based chemistries. Printed cells with electrodes as small as 1 mm² maintain steady operating voltages above (>1.4 V) at high current densities (1–12 mA cm^?2) and achieve the highest reported areal capacity for a fully printed battery at 11 mAh cm^?2. The findings represent the first demonstration of a small, packaged, fully printed Zn–Ag₂O battery with high areal capacities at high current densities, a crucial step toward realizing chip‐scale energy storage for integrated electronic systems.     

In Situ Assembly of 2D Conductive Vanadium Disulfide with Graphene as a High‐Sulfur‐Loading Host for Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries are deemed to be one of the most promising energy storage technologies because of their high energy density, low cost, and environmental benignancy. However, existing drawbacks including the shuttling of intermediate polysulfides, the insulating nature of sulfur, and the considerable volume change of sulfur cathode would otherwise result in the capacity fading and unstable cycling. To overcome these challenges, herein an in situ assembly route is presented to fabricate VS₂/reduced graphene oxide nanosheets (G–VS₂) as a sulfur host. Benefiting from the 2D conductive and polar VS₂ interlayered within a graphene framework, the obtained G–VS₂ hybrids can effectively suppress the polysulfide shuttling, facilitate the charge transport, and cushion the volume expansion throughout the synergistic effect of structural confinement and chemical anchoring. With these advantageous features, the obtained sulfur cathode (G–VS₂/S) can deliver an outstanding rate capability (≈950 and 800 mAh g^?1 at 1 and 2 C, respectively) and an impressive cycling stability at high rates (retaining ≈532 mAh g^?1 after 300 cycles at 5 C). More significantly, it enables superior cycling performance of high‐sulfur‐loading cathodes (achieving an areal capacity of 5.1 mAh cm^?2 at 0.2 C with a sulfur loading of 5 mg cm^?2) even at high current densities.     

Novel Graphene Hydrogel/B‐Doped Graphene Quantum Dots Composites as Trifunctional Electrocatalysts for Zn−Air Batteries and Overall Water Splitting

Herein, a facile, one‐step hydrothermal route to synthesize novel all‐carbon‐based composites composed of B‐doped graphene quantum dots anchored on a graphene hydrogel (GH‐BGQD) is demonstrated. The obtained GH‐BGQD material has a unique 3D architecture with high porosity and large specific surface area, exhibiting abundant catalytic active sites of B‐GQDs as well as enhanced electrolyte mass transport and ion diffusion. Therefore, the prepared GH‐BGQD composites exhibit a superior trifunctional electrocatalytic activity toward the oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction with excellent long‐term stability and durability comparable to those of commercial Pt/C and Ir/C catalysts. A flexible solid‐state Zn–air battery using a GH‐BGQD air electrode achieves an open‐circuit voltage of 1.40 V, a stable discharge voltage of 1.23 V for 100 h, a specific capacity of 687 mAh g^?1, and a peak power density of 112 mW cm^?2. Also, a water electrolysis cell using GH‐BGQD electrodes delivers a current density of 10 mA cm^?2 at cell voltage of 1.61 V, with remarkable stability during 70 h of operation. Finally, the trifunctional GH‐BGQD catalyst is employed for water electrolysis cell powered by the prepared Zn–air batteries, providing a new strategy for the carbon‐based multifunctional electrocatalysts for electrochemical energy devices.     

One‐Step Synthesis of 2‐Ethylhexylamine Pillared Vanadium Disulfide Nanoflowers with Ultralarge Interlayer Spacing for High‐Performance Magnesium Storage

Rechargeable magnesium batteries (RMBs) are attractive candidates for large‐scale energy storage owing to the high theoretical specific capacity, rich earth abundance, and good safety characteristics. However, the development of desirable cathode materials for RMBs is constrained by the high polarity and slow intercalation kinetics of Mg²⁺ ions. Herein, it is demonstrated that 2‐ethylhexylamine pillared vanadium disulfide nanoflowers (expanded VS₂) with enlarged interlayer distances exhibit greatly boosted electrochemical performance as a cathode material in RMBs. Through a one‐step solution‐phase synthesis and in situ 2‐ethylhexylamine intercalation process, VS₂ nanoflowers with ultralarge interlayer spacing are prepared. A series of ex situ characterizations verify that the cathode of expanded VS₂ nanoflowers undergoes a reversible intercalation reaction mechanism, followed by a conversion reaction mechanism. Electrochemical kinetics analysis reveal a relatively fast Mg‐ion diffusivity of expanded VS₂ nanoflowers in the order of 10^?11–10^?12 cm² s^?1, and the pseudocapacitive contribution is up to 64% for the total capacity at 1 mV s^?1. The expanded VS₂ nanoflowers show highly reversible discharge capacity (245 mAh g^?1 at 100 mA g^?1), good rate capability (103 mAh g^?1 at 2000 mA g^?1), and stable cycling performance (90 mAh g^?1 after 600 cycles at 1000 mA g^?1).     

Achieving High‐Voltage and High‐Capacity Aqueous Rechargeable Zinc Ion Battery by Incorporating Two‐Species Redox Reaction

Herein, a two‐species redox reaction of Co(II)/Co(III) and Fe(II)/Fe(III) incorporated in cobalt hexacyanoferrate (CoFe(CN)6) is proposed as a breakthrough to achieve jointly high‐capacity and high‐voltage aqueous Zn‐ion battery. The Zn/CoFe(CN)₆ battery provides a highly operational voltage plateau of 1.75 V (vs metallic Zn) and a high capacity of 173.4 mAh g^?1 at current density of 0.3 A g^?1, taking advantage of the two‐species redox reaction of Co(II)/Co(III) and Fe(II)/Fe(III) couples. Even under extremely fast charge/discharge rate of 6 A g^?1, the battery delivers a sufficiently high discharge capacity of 109.5 mAh g^?1 with its 3D opened structure framework. This is the highest capacity delivered among all the batteries using Prussian blue analogs (PBAs) cathode up to now. Furthermore, Zn/CoFe(CN)₆ battery achieves an excellent cycling performance of 2200 cycles without any capacity decay at coulombic efficiency of nearly 100%. One further step, a sol–gel transition strategy for hydrogel electrolyte is developed to construct high‐performance flexible cable‐type battery. With the strategy, the active materials can adequately contact with electrolyte, resulting in improved electrochemical performance (≈18.73% capacity increase) and mechanical robustness of the solid‐state device. It is believed that this study optimizes electrodes by incorporating multi redox reaction species for high‐voltage and high‐capacity batteries.     

Partially Reduced Holey Graphene Oxide as High Performance Anode for Sodium‐Ion Batteries

The current Na⁺ storage performance of carbon‐based materials is still hindered by the sluggish Na⁺ ion transfer kinetics and low capacity. Graphene and its derivatives have been widely investigated as electrode materials in energy storage and conversion systems. However, as anode materials for sodium‐ion batteries (SIBs), the severe π–π restacking of graphene sheets usually results in compact structure with a small interlayer distance and a long ion transfer distance, thus leading to low capacity and poor rate capability. Herein, partially reduced holey graphene oxide is prepared by simple H₂O₂ treatment and subsequent low temperature reduction of graphene oxide, leading to large interlayer distance (0.434 nm), fast ion transport, and larger Na⁺ storage space. The partially remaining oxygenous groups can also contribute to the capacity by redox reaction. As anode material for SIBs, the optimized electrode delivers high reversible capacity, high rate capability (365 and 131 mAh g^?1 at 0.1 and 10 A g^?1, respectively), and good cycling performance (163 mAh g^?1 after 3000 cycles at a current density of 2 A g^?1), which is among the best reported performances for carbon‐based SIB anodes.     

Synergy Between Metal Oxide Nanofibers and Graphene Nanoribbons for Rechargeable Lithium‐Oxygen Battery Cathodes

The challenges for rechargeable lithium‐oxygen batteries of low practical capacity and poor round‐trip efficiency urgently demand effective cathode materials to overcome the limitations. However, the synergy between the multiple active materials is not well understood. Here, findings of the synergistic effect between electrospun zinc oxide (ZnO) nanofibers and graphene nanoribbons (GNRs) unzipped from carbon nanotubes (CNTs) as cathode materials in rechargeable lithium‐oxygen batteries are described. Furthermore, the overpotentials and discharge capacities are tuned by the surface defect states of ZnO nanofibers and Pt nanocrytals in GNRs. It is observed that the optimized zinc oxide nanofibers hybridized with GNRs achieved a high reversible capacity of 6300 mAh g^‐1_carbon and enhanced stable cyclability under specific 50% of full discharge capacities. This report demonstrates that the ZnO nanofibers with a high degree of defects and hydrophilicity of the surface may be a promising cathode component for rechargeable lithium‐oxygen batteries and the optimum synergy between ZnO nanofibers and GNRs can balance the discharge capacity and cycle life.     

Molecular Engineering of Monodisperse SnO2 Nanocrystals Anchored on Doped Graphene with High‐Performance Lithium/Sodium‐Storage Properties in Half/Full Cells

The fabrication of ultrasmall and high‐content SnO₂ nanocrystals anchored on doped graphene can endow SnO₂ with superior electrochemical properties. Herein, an effective strategy, involving molecular engineering of a layer‐by‐layer assembly technique, is proposed to homogeneously anchor SnO₂ nanocrystals on nitrogen/sulfur codoped graphene (NSGS), which serves as an advanced anode material in lithium/sodium‐ion batteries (LIBs/SIBs). Benefiting from novel design and specific structure, the optimized NSGS for LIBs displays high initial capacity (2123.9 mAh g^?1 at 0.1 A g^?1), long‐term cycling performance (only 0.8% loss after 500 cycles), and good rate capability (477.4 mAh g^?1 at 5 A g^?1). In addition, the optimized NSGS for SIBs also delivers high initial capacity (791.7 mAh g^?1 at 0.1 A g^?1) and high reversible capacity (180.2 mAh g^?1 after 500 cycles at 0.5 A g^?1). Meanwhile, based on the detailed analysis of phase transition and electrochemical reaction kinetics, the reaction mechanisms of NSGS in LIBs and SIBs as well as the distinction in LIBs/SIBs are clearly articulated. Notably, to further explore the practical application, Li/Na⁺ full cells are also assembled by coupling the optimized NSGS anode with LiCoO₂ and Na₃V₂(PO₄)₃/C cathodes, respectively.     

Hierarchical Zn–Co–S Nanowires as Advanced Electrodes for All Solid State Asymmetric Supercapacitors

A facile two‐step strategy is developed to design the large‐scale synthesis of hierarchical, unique porous architecture of ternary metal hydroxide nanowires grown on porous 3D Ni foam and subsequent effective sulfurization. The hierarchical Zn–Co–S nanowires (NWs) arrays are directly employed as an electrode for supercapacitors application. The as‐synthesized Zn–Co–S NWs deliver an ultrahigh areal capacity of 0.9 mA h cm^?2 (specific capacity of 366.7 mA h g^?1) at a current density of 3 mA cm^?2, with an exceptional rate capability (≈227.6 mA h g^?1 at a very high current density of 40 mA cm^?2) and outstanding cycling stability (≈93.2% of capacity retention after 10 000 cycles). Most significantly, the assembled Zn–Co–S NWs//Fe₂O₃@reduced graphene oxide asymmetric supercapacitors with a wide operating potential window of ≈1.6 V yield an ultrahigh volumetric capacity of ≈1.98 mA h cm^?3 at a current density of 3 mA cm^?2, excellent energy density of ≈81.6 W h kg^?1 at a power density of ≈559.2 W kg^?1, and exceptional cycling performance (≈92.1% of capacity retention after 10 000 cycles). This general strategy provides an alternative to design the other ternary metal sulfides, making it facile, free‐standing, binder‐free, and cost‐effective ternary metal sulfide‐based electrodes for large‐scale applications in modern electronics.     

An Air‐Stable Densely Packed Phosphorene–Graphene Composite Toward Advanced Lithium Storage Properties

Phosphorene, monolayer or few‐layer black phosphorus (BP), has recently triggered strong scientific interest for lithium/sodium ion batteries (LIBs/SIBs) applications. However, there are still challenges regarding large‐scale fabrication, poor air stability. Herein, we report the high‐yield synthesis of phosphorene with good crystallinity and tunable size distributions via liquid‐phase exfoliation of bulk BP in formamide. Afterwards, a densely packed phosphorene–graphene composite (PG‐SPS, a packing density of 0.6 g cm^?3) is prepared by a simple and easily up‐scalable spark plasma sintering (SPS) process. When working as anode materials of LIBs, PG‐SPS exhibit much improved first‐cycle Coloumbic efficiency (60.2%) compared to phosphorene (11.5%) and loosely stacked phosphorene–graphene composite (34.3%), high specific capacity (1306.7 mAh g^?1) and volumetric capacity (256.4 mAh cm^?3), good rate capabilities (e.g., 415.0 mAh g^?1 at 10 A g^?1) as well as outstanding long‐term cycling life (91.9% retention after 800 cycles at 10 A g^?1). Importantly, excellent air stability of PG‐SPS over the 60 days observation in maintaining its high Li storage properties can be achieved. On the contrary, 95.2% of BP in PG sample was oxidized after only 10 days exposure to ambience, leading to severe degradation of electrochemical properties.     

Nonwoven rGO Fiber‐Aramid Separator for High‐Speed Charging and Discharging of Li Metal Anode

Li metal, which has a high theoretical specific capacity and low redox potential, is considered to the most promising anode material for next‐generation Li ion‐based batteries. However, it also exhibits a disadvantageous solid electrolyte interphase (SEI) layer problem that needs to be resolved. Herein, an advanced separator composed of reduced graphene oxide fiber attached to aramid paper (rGOF‐A) is introduced. When rGOF‐A is applied, F^? anions, generated from the decomposition of the LiPF₆ electrolyte during the SEI layer formation process form semi‐ionic C? F bonds along the surface of rGOF. As Li⁺ ions are plated, the “F‐doped” rGO surface induces the formation of LiF, which is known as a component of a chemically stable SEI, therefore it helps the Li metal anode to operate stably at a high current of 20 mA cm^?2 with a high capacity of 20 mAh cm^?2. The proposed rGOF‐A separator successfully achieves a stable SEI layer that could resolve the interfacial issues of the Li metal anode.