A New Strategy to Build a High‐Performance P′2‐Type Cathode Material through Titanium Doping for Sodium‐Ion Batteries

Herein, Ti⁴⁺ in P′2‐Na_0.67[(Mn_0.78Fe_0.22)_0.9Ti_0.1]O₂ is proposed as a new strategy for optimization of Mn‐based cathode materials for sodium‐ion batteries, which enables a single phase reaction during de‐/sodiation. The approach is to utilize the stronger Ti–O bond in the transition metal layers that can suppress the movements of Mn–O and Fe–O by sharing the oxygen with Ti by the sequence of Mn–O–Ti–O–Fe. It delivers a discharge capacity of ≈180 mAh g^?1 over 200 cycles (86% retention), with S‐shaped smooth charge–discharge curves associated with a small volume change during cycling. The single phase reaction with a small volume change is further confirmed by operando synchrotron X‐ray diffraction. The low activation barrier energy of ≈541 meV for Na⁺ diffusion is predicted using first‐principles calculations. As a result, Na_0.67[(Mn_0.78Fe_0.22)_0.9Ti_0.1]O₂ can deliver a high reversible capacity of ≈153 mAh g^?1 even at 5C (1.3 A g^?1), which corresponds to ≈85% of the capacity at 0.1C (26 mA g^?1). The nature of the sodium storage mechanism governing the ultrahigh electrode performance in a full cell with a hard carbon anode is elucidated, revealing the excellent cyclability and good retention (≈80%) for 500 cycles (111 mAh g^?1) at 5C (1.3 A g^?1).     

Novel Insoluble Organic Cathodes for Advanced Organic K‐Ion Batteries

Organic redox‐active molecules are inborn electrodes to store large‐radius potassium (K) ion. High‐performance organic cathodes are important for practical usage of organic potassium‐ion batteries (OPIBs). However, small‐molecule organic cathodes face serious dissolution problems against liquid electrolytes. A novel insoluble small‐molecule organic cathode [N,N′‐bis(2‐anthraquinone)]‐perylene‐3,4,9,10‐tetracarboxydiimide (PTCDI‐DAQ, 200 mAh g^?1) is initially designed for OPIBs. In half cells (1–3.8 V vs K⁺/K) using 1 m KPF₆ in dimethoxyethane (DME), PTCDI‐DAQ delivers a highly stable specific capacity of 216 mAh g^?1 and still holds the value of 133 mAh g^?1 at an ultrahigh current density of 20 A g^?1 (100 C). Using reduced potassium terephthalate (K₄TP) as the organic anode, the resulting K₄TP||PTCDI‐DAQ OPIBs with the electrolyte 1 m KPF₆ in DME realize a high energy density of maximum 295 Wh kg^?1_cathode (213 mAh g^?1_cathode × 1.38 V) and power density of 13 800 W Kg^?1_cathode (94 mAh g^?1 × 1.38 V @ 10 A g^?1) during the working voltage of 0.2–3.2 V. Meanwhile, K₄TP||PTCDI‐DAQ OPIBs fulfill the superlong lifespan with a stable discharge capacity of 62 mAh g^?1_cathode after 10 000 cycles and 40 mAh g^?1_cathode after 30 000 cycles (3 A g^?1). The integrated performance of PTCDI‐DAQ can currently defeat any cathode reported in K‐ion half/full cells.     

Copper Thiophosphate (Cu3PS4) as Electrode for Sodium‐Ion Batteries with Ether Electrolyte

Lithium and sodium thiophosphates (and related compounds) have recently attracted attention because of their potential use as solid electrolytes in solid‐state batteries. These compounds, however, exhibit only limited stability in practice as they react with the electrodes. The decomposition products partially remain redox active hence leading to excess capacity. The redox activity of thiophosphates is explicitly used to act as electrode for sodium‐ion batteries. Copper thiophosphate (Cu₃PS₄) is used as a model system. The storage behavior between 0.01 and 2.5 V versus Na⁺/Na is studied in half cells using different electrolytes with 1 m NaPF₆ in diglyme showing the best result. Cu₃PS₄ shows highly reversible charge storage with capacities of about 580 mAh g^?1 for more than 200 cycles @120 mA g^?1 and about 450 mAh g^?1 for 1400 cycles @1 A g^?1. The redox behavior is studied by operando X‐ray diffraction and X‐ray photoelectron spectroscopy. During initial sodiation, Cu₃PS₄ undergoes a conversion reaction including the formation of Cu and Na₂S. During cycling, the redox activity seems dominated by sulfur. Interestingly, the capacity of Cu₃PS₄ for lithium storage is smaller, leading to about 170 mAh g^?1 after 200 cycles. The results demonstrate that thiophosphates can lead to reversible charge storage over several hundred cycles without any notable capacity decay.     

Multicore–Shell Bi@N‐doped Carbon Nanospheres for High Power Density and Long Cycle Life Sodium‐ and Potassium‐Ion Anodes

Bismuth (Bi) is an attractive material as anodes for both sodium‐ion batteries (NIBs) and potassium‐ion batteries (KIBs), because it has a high theoretical gravimetric capacity (386 mAh g^?1) and high volumetric capacity (3800 mAh L^?1). The main challenges associated with Bi anodes are structural degradation and instability of the solid electrolyte interphase (SEI) resulting from the huge volume change during charge/discharge. Here, a multicore–shell structured Bi@N‐doped carbon (Bi@N‐C) anode is designed that addresses these issues. The nanosized Bi spheres are encapsulated by a conductive porous N‐doped carbon shell that not only prevents the volume expansion during charge/discharge but also constructs a stable SEI during cycling. The Bi@N‐C exhibits unprecedented rate capability and long cycle life for both NIBs (235 mAh g^?1 after 2000 cycles at 10 A g^?1) and KIBs (152 mAh g^?1 at 100 A g^?1). The kinetic analysis reveals the outstanding electrochemical performance can be attributed to significant pseudocapacitance behavior upon cycling.     

Interfacial Bonding of Metal‐Sulfides with Double Carbon for Improving Reversibility of Advanced Alkali‐Ion Batteries

Engineering interfacial properties of metal‐sulfides toward excellent electrochemical capability is imperative for advanced energy‐storage materials. However, they still suffer from an unclear mechanism of capacity fading, along with ineffective physical–chemical evolution. Herein, a highly‐effective Sb₂S₃ with double carbon is designed with interfacial Sb? C bonds and double carbon, which boosts promoting of ion transferring and alleviates the separation of both active phases (Sb, S). Through “voltage‐cutting” manners, the key elements of capacity improvement about phase transitions are further determined. As expected, even at 5.0 A g^?1, the lithium‐storage capacity remains about 674 mAh g^?1. Utilized as sodium ion battery (SIB) anode, the rate capacity still reaches up to 366 mAh g^?1 at 3.0 A g^?1, much larger than that of Sb₂S₃. Obtaining the full cell of Ni–Fe Prussian blue analog versus M‐Sb₂S₃@DC, the reversible capacity is 330 mAh g^?1 at 0.5 A g^?1. Supported by kinetic analysis, the excellent rate properties are determined by the surface‐controlling behaviors, mainly resulting from the decreased capacitive resistance and improved ion moving. Furthermore, the reassembling evolution of active phases is revealed in detail by ex situ techniques. This work is expected to offer significant insights into interfacial evolutions toward advanced energy‐storage systems.     

Walnut‐Like Multicore–Shell MnO Encapsulated Nitrogen‐Rich Carbon Nanocapsules as Anode Material for Long‐Cycling and Soft‐Packed Lithium‐Ion Batteries

Metal oxide‐based nanomaterials are widely studied because of their high‐energy densities as anode materials in lithium‐ion batteries. However, the fast capacity degradation resulting from the large volume expansion upon lithiation hinders their practical application. In this work, the preparation of walnut‐like multicore–shell MnO encapsulated nitrogen‐rich carbon nanocapsules (MnO@NC) is reported via a facile and eco‐friendly process for long‐cycling Li‐ion batteries. In this hybrid structure, MnO nanoparticles are uniformly dispersed inside carbon nanoshells, which can simultaneously act as a conductive framework and also a protective buffer layer to restrain the volume variation. The MnO@NC nanocapsules show remarkable electrochemical performances for lithium‐ion batteries, exhibiting high reversible capability (762 mAh g^?1 at 100 mA g^?1) and stable cycling life (624 mAh g^?1 after 1000 cycles at 1000 mA g^?1). In addition, the soft‐packed full batteries based on MnO@NC nanocapsules anodes and commercial LiFePO₄ cathodes present good flexibility and cycling stability.     

Understanding the Charge Storage Mechanism to Achieve High Capacity and Fast Ion Storage in Sodium‐Ion Capacitor Anodes by Using Electrospun Nitrogen‐Doped Carbon Fibers

Microporous nitrogen‐rich carbon fibers (HAT‐CNFs) are produced by electrospinning a mixture of hexaazatriphenylene‐hexacarbonitrile (HAT‐CN) and polyvinylpyrrolidone and subsequent thermal condensation. Bonding motives, electronic structure, content of nitrogen heteroatoms, porosity, and degree of carbon stacking can be controlled by the condensation temperature due to the use of the HAT‐CN with predefined nitrogen binding motives. The HAT‐CNFs show remarkable reversible capacities (395 mAh g^?1 at 0.1 A g^?1) and rate capabilities (106 mAh g^?1 at 10 A g^?1) as an anode material for sodium storage, resulting from the abundant heteroatoms, enhanced electrical conductivity, and rapid charge carrier transport in the nanoporous structure of the 1D fibers. HAT‐CNFs also serve as a series of model compounds for the investigation of the contribution of sodium storage by intercalation and reversible binding on nitrogen sites at different rates. There is an increasing contribution of intercalation to the charge storage with increasing condensation temperature which becomes less active at high rates. A hybrid sodium‐ion capacitor full cell combining HAT‐CNF as the anode and salt‐templated porous carbon as the cathode provides remarkable performance in the voltage range of 0.5–4.0 V (95 Wh kg^?1 at 0.19 kW kg^?1 and 18 Wh kg^?1 at 13 kW kg^?1).     

MoSe2‐Covered N,P‐Doped Carbon Nanosheets as a Long‐Life and High‐Rate Anode Material for Sodium‐Ion Batteries

MoSe₂ grown on N,P‐co‐doped carbon nanosheets is synthesized by a solvothermal reaction followed with a high‐temperature calcination. This composite has an interlayer spacing of MoSe₂ expanded to facilitate sodium‐ion diffusion, MoSe₂ immobilized on carbon nanosheets to improve charge‐transfer kinetics, and N and P incorporated into carbon to enhance its interaction with active species upon cycling. These features greatly improve the electrochemical performance of this composite, as compared to all the controls. It presents a specific capacity of 378 mAh g^?1 after 1000 cycles at 0.5 A g^?1, corresponding to 87% of the capacity at the second cycle. Ex situ Raman spectra and high‐resolution transmission electron microscopy images confirm that it is element Se, rather than MoSe₂, formed after the charging process. The interaction of the active species with modified carbon is simulated using density functional theory to explain this excellent stability. The superior rate capability, where the capacity at 15 A g^?1 equals ≈55% of that at 0.5 A g^?1, could be associated with the significant contribution of pseudocapacitance. By pairing with homemade Na₃V₂(PO₄)₃/C, this composite also exhibits excellent performances in full cells.     

Rambutan‐Like Hybrid Hollow Spheres of Carbon Confined Co3O4 Nanoparticles as Advanced Anode Materials for Sodium‐Ion Batteries

Transition metal oxides, possessing high theoretical specific capacities, are promising anode materials for sodium‐ion batteries. However, the sluggish sodiation/desodiation kinetics and poor structural stability restrict their electrochemical performance. To achieve high and fast Na storage capability, in this work, rambutan‐like hybrid hollow spheres of carbon confined Co₃O₄ nanoparticles are synthesized by a facile one‐pot hydrothermal treatment with postannealing. The hierarchy hollow structure with ultrafine Co₃O₄ nanoparticles embedded in the continuous carbon matrix enables greatly enhanced structural stability and fast electrode kinetics. When tested in sodium‐ion batteries, the hollow structured composite electrode exhibits an outstandingly high reversible specific capacity of 712 mAh g^?1 at a current density of 0.1 A g^?1, and retains a capacity of 223 mAh g^?1 even at a large current density of 5 A g^?1. Besides the superior Na storage capability, good cycle performance is demonstrated for the composite electrode with 74.5% capacity retention after 500 cycles, suggesting promising application in advanced sodium‐ion batteries.     

All‐Cellulose‐Based Quasi‐Solid‐State Sodium‐Ion Hybrid Capacitors Enabled by Structural Hierarchy

Na‐ion hybrid capacitors consisting of battery‐type anodes and capacitor‐style cathodes are attracting increasing attention on account of the abundance of sodium‐based resources as well as the potential to bridge the gap between batteries (high energy) and supercapacitors (high power). Herein, hierarchically structured carbon materials inspired by multiscale building units of cellulose from nature are assembled with cellulose‐based gel electrolytes into Na‐ion capacitors. Nonporous hard carbon anodes are obtained through the direct thermal pyrolysis of cellulose nanocrystals. Nitrogen‐doped carbon cathodes with a coral‐like hierarchically porous architecture are prepared via hydrothermal carbonization and activation of cellulose microfibrils. The reversible charge capacity of the anode is 256.9 mAh g^?1 when operating at 0.1 A g^?1 from 0 to 1.5 V versus Na⁺/Na, and the discharge capacitance of cathodes tested within 1.5 to 4.2 V versus Na⁺/Na is 212.4 F g^?1 at 0.1 A g^?1. Utilizing Na⁺ and ClO₄^? as charge carriers, the energy density of the full Na‐ion capacitor with two asymmetric carbon electrodes can reach 181 Wh kg^?1 at 250 W kg^?1, which is one of the highest energy devices reported until now. Combined with macrocellulose‐based gel electrolytes, all‐cellulose‐based quasi‐solid‐state devices are demonstrated possessing additional advantages in terms of overall sustainability.     

Three Electron Reversible Redox Reaction in Sodium Vanadium Chromium Phosphate as a High‐Energy‐Density Cathode for Sodium‐Ion Batteries

A sodium‐ion battery operating at room temperature is of great interest for large‐scale stationary energy storage because of its intrinsic cost advantage. However, the development of a high capacity cathode with high energy density remains a great challenge. In this work, sodium super ionic conductor‐structured Na₃V_2?xCr_x(PO₄)₃ is achieved through the sol–gel method; Na₃V_1.5Cr_0.5(PO₄)₃ is demonstrated to have a capacity of 150 mAh g^?1 with reversible three‐electron redox reactions after insertion of a Na⁺, consistent with the redox couples of V²⁺/³⁺, V³⁺/⁴⁺, and V⁴⁺/⁵⁺. Moreover, a symmetric sodium‐ion full cell utilizing Na₃V_1.5Cr_0.5(PO₄)₃ as both the cathode and anode exhibits an excellent rate capability and cyclability with a capacity of 70 mAh g^?1 at 1 A g^?1. Ex situ X‐ray diffraction analysis and in situ impedance measurements are performed to reveal the sodium storage mechanism and the structural evolution during cycling.     

A General Metal‐Organic Framework (MOF)‐Derived Selenidation Strategy for In Situ Carbon‐Encapsulated Metal Selenides as High‐Rate Anodes for Na‐Ion Batteries

On account of increasing demand for energy storage devices, sodium‐ion batteries (SIBs) with abundant reserve, low cost, and similar electrochemical properties have the potential to partly replace the commercial lithium‐ion batteries. In this study, a facile metal‐organic framework (MOF)‐derived selenidation strategy to synthesize in situ carbon‐encapsulated selenides as superior anode for SIBs is rationally designed. These selenides with particular micro‐ and nanostructured features deliver ultrastable cycling performance at high charge–discharge rate and demonstrate ultraexcellent rate capability. For example, the uniform peapod‐like Fe₇Se₈@C nanorods represent a high specific capacity of 218 mAh g^?1 after 500 cycles at 3 A g^?1 and the porous NiSe@C spheres display a high specific capacity of 160 mAh g^?1 after 2000 cycles at 3 A g^?1. The current simple MOF‐derived method could be a promising strategy for boosting the development of new functional inorganic materials for energy storage, catalysis, and sensors.     

Dual‐Doped Hematite Nanorod Arrays on Carbon Cloth as a Robust and Flexible Sodium Anode

Rechargeable batteries with flexibility can find tremendous applications in wearable and bendable electronics. One central mission for the advancement of such high‐performance batteries is the exploration of flexible anodes with electrochemical and mechanical robustness. Herein reported is a robust and flexible sodium‐ion anode based on self‐supported hematite nanoarray grown on carbon cloth. The ammonia treatment that results in dual doping of both nitrogen and low‐valent iron renders surface reactivity and electric conductivity to the material. The dual‐doped hematite arrays afford a robust activity for sodium storage, exhibiting reversible capacities of 895 and 382 mAh g^?1 at current rates of 0.1 and 5 A g^?1, respectively, or 615 and 356 mAh g^?1 by removing the contribution of the substrate. They also sustain 85% of the initial capacity upon 200 cycles at 0.2 A g^?1. To demonstrate the flexibility, full cells composed of a hematite array anode and Na₃V₂(PO₄)₃/C cathode are assembled. The cell is capable of affording an energy density of 201 Wh kg^?1 and sustaining repeated bending without performance decay, demonstrating a significant potential in practical application.     

General Synthesis of Dual Carbon‐Confined Metal Sulfides Quantum Dots Toward High‐Performance Anodes for Sodium‐Ion Batteries

Sponge‐like composites assembled by cobalt sulfides quantum dots (Co₉S₈ QD), mesoporous hollow carbon polyhedral (HCP) matrix, and a reduced graphene oxide (rGO) wrapping sheets are synthesized by a simultaneous thermal reduction, carbonization, and sulfidation of zeolitic imidazolate frameworks@GO precursors. Specifically, Co₉S₈ QD with size less than 4 nm are homogenously embedded within HCP matrix, which is encapsulated in macroporous rGO, thereby leading to the double carbon‐confined hierarchical composites with strong coupling effect. Experimental data combined with density functional theory calculations reveal that the presence of coupled rGO not only prevents the aggregation and excessive growth of particles, but also expands the lattice parameters of Co₉S₈ crystals, enhancing the reactivity for sodium storage. Benefiting from the hierarchical porosity, conductive network, structural integrity, and a synergistic effect of the components, the sponge‐like composites used as binder‐free anodes manifest outstanding sodium‐storage performance in terms of excellent stable capacity (628 mAh g^?1 after 500 cycles at 300 mA g^?1) and exceptional rate capability (529, 448, and 330 mAh g^?1 at 1600, 3200, and 6400 mA g^?1). More importantly, the synthetic method is very versatile and can be easily extended to fabricate other transition‐metal‐sulfides‐based sponge‐like composites with excellent electrochemical performances.     

Potassium Prussian Blue Nanoparticles: A Low‐Cost Cathode Material for Potassium‐Ion Batteries

Potassium‐ion batteries (KIBs) in organic electrolytes hold great promise as an electrochemical energy storage technology owing to the abundance of potassium, close redox potential to lithium, and similar electrochemistry with lithium system. Although carbon materials have been studied as KIB anodes, investigations on KIB cathodes have been scarcely reported. A comprehensive study on potassium Prussian blue K_0.220Fe[Fe(CN)₆]_0.805?4.01H₂O nanoparticles as a potential cathode material is for the first time reported. The cathode exhibits a high discharge voltage of 3.1–3.4 V, a high reversible capacity of 73.2 mAh g^?1, and great cyclability at both low and high rates with a very small capacity decay rate of ≈0.09% per cycle. Electrochemical reaction mechanism analysis identifies the carbon‐coordinated Fe^III/Fe^II couple as redox‐active site and proves structural stability of the cathode during charge/discharge. Furthermore, for the first time, a KIB full‐cell is presented by coupling the nanoparticles with commercial carbon materials. The full‐cell delivers a capacity of 68.5 mAh g^?1 at 100 mA g^?1 and retains 93.4% of the capacity after 50 cycles. Considering the low cost and material sustainability as well as the great electrochemical performances, this work may pave the way toward more studies on KIB cathodes and trigger future attention on rechargeable KIBs.     

Carbon Nanotubes Rooted in Porous Ternary Metal Sulfide@N/S‐Doped Carbon Dodecahedron: Bimetal‐Organic‐Frameworks Derivation and Electrochemical Application for High‐Capacity and Long‐Life Lithium‐Ion Batteries

Lithium ion battery is the predominant power source for portable electronic devices, electrical vehicles, and back‐up electricity storage units for clean and renewable energies. High‐capacity and long‐life electrode materials are essential for the next‐generation Li‐ion battery with high energy density. Here bimetal‐organic‐frameworks synthesis of Co_0.4Zn_0.19S@N and S codoped carbon dodecahedron is shown with rooted carbon nanotubes (Co‐Zn‐S@N‐S‐C‐CNT) for high‐performance Li‐ion battery application. Benefiting from the synergetic effect of two metal sulfide species for Li‐storage at different voltages, mesoporous dodecahedron structure, N and S codoped carbon overlayer and deep‐rooted CNTs network, the product exhibits a larger‐than‐theoretical reversible Li‐storage capacity of 941 mAh g^?1 after 250 cycles at 100 mA g^?1 and excellent high‐rate capability (734, 591, 505 mAh g^?1 after 500 cycles at large current densities of 1, 2, and 5 A g^?1 , respectively).     

Metal–Organic Framework (MOF) Derived Electrodes with Robust and Fast Lithium Storage for Li‐Ion Hybrid Capacitors

Hybrid metal–organic frameworks (MOFs) demonstrate great promise as ideal electrode materials for energy‐related applications. Herein, a well‐organized interleaved composite of graphene‐like nanosheets embedded with MnO₂ nanoparticles (MnO₂@C‐NS) using a manganese‐based MOF and employed as a promising anode material for Li‐ion hybrid capacitor (LIHC) is engineered. This unique hybrid architecture shows intriguing electrochemical properties including high reversible specific capacity 1054 mAh g^?1 (close to the theoretical capacity of MnO₂, 1232 mAh g^?1) at 0.1 A g^?1 with remarkable rate capability and cyclic stability (90% over 1000 cycles). Such a remarkable performance may be assigned to the hierarchical porous ultrathin carbon nanosheets and tightly attached MnO₂ nanoparticles, which provide structural stability and low contact resistance during repetitive lithiation/delithiation processes. Moreover, a novel LIHC is assembled using a MnO₂@C‐NS anode and MOF derived ultrathin nanoporous carbon nanosheets (derived from other potassium‐based MOFs) cathode materials. The LIHC full‐cell delivers an ultrahigh specific energy of 166 Wh kg^?1 at 550 W kg^?1 and maintained to 49.2 Wh kg^?1 even at high specific power of 3.5 kW kg^?1 as well as long cycling stability (91% over 5000 cycles). This work opens new opportunities for designing advanced MOF derived electrodes for next‐generation energy storage devices.     

Facile Spraying Synthesis and High‐Performance Sodium Storage of Mesoporous MoS2/C Microspheres

A facile one‐step spraying synthesis of MoS₂/C microspheres and their enhanced electrochemical performance as anode of sodium‐ion batteries is reported. An aerosol spraying pyrolysis without any template is employed to synthesize MoS₂/C microspheres, in which ultrathin MoS₂ nanosheets (≈2 nm) with enlarged interlayers (≈0.64 nm) are homogeneously embedded in mesoporous carbon microspheres. The as‐synthesized mesoporous MoS₂/C microspheres with 31 wt% carbon have been applied as an anode material for sodium ion batteries, demonstrating long cycling stability (390 mAh g^?1 after 2500 cycles at 1.0 A g^?1) and high rate capability (312 mAh g^?1 at 10.0 A g^?1 and 244 mAh g^?1 at 20.0 A g^?1). The superior electrochemical performance is due to the uniform distribution of ultrathin MoS₂ nanosheets in mesoporous carbon frameworks. This kind of structure not only effectively improves the electronic and ionic transport through MoS₂/C microspheres, but also minimizes the influence of pulverization and aggregation of MoS₂ nanosheets during repeated sodiation and desodiation.     

Face‐to‐Face Contact and Open‐Void Coinvolved Si/C Nanohybrids Lithium‐Ion Battery Anodes with Extremely Long Cycle Life

To develop high‐performance anode materials of lithium‐ion batteries (LIBs) instead of commercial graphite for practical applications, herein, a layer of silicon has been well‐anchored onto a 3D graphene/carbon nanotube (CNT) aerogels (CAs) framework with face‐to‐face contact and balanced open void by a simple chemical vapor deposition strategy. The engineered contact interface between CAs and Si creates high‐efficiency channels for the rapid electrons and lithium ions transport, and meanwhile, the balanced open‐void allows the free expansion of Si during cycling while maintaining high structural integrity due to the robust mechanical strength of 3D CAs framework. As a consequence, the as‐synthesized Si/CAs nanohybrids are highly stable anode materials for LIBs with a high reversible discharge capacity (1498 mAh g^?1 at 200 mA g^?1) and excellent rate capability (462 mAh g^?1 at 10 000 mA g^?1), which is much better than Si/graphene‐CNTs‐mixture (51 mAh g^?1 at 10 000 mA g^?1). More significantly, it is found that the Si/CAs nanohybrids display no obvious capacity decline even after 2000 cycles at a high current density of 10 000 mA g^?1. The present Si/CAs nanohybrids are one of the most stable Si‐based anode materials ever reported for LIBs to date.     

Solid‐State Plastic Crystal Electrolytes: Effective Protection Interlayers for Sulfide‐Based All‐Solid‐State Lithium Metal Batteries

All‐solid‐state lithium metal batteries (ASSLMBs) have attracted significant attention due to their superior safety and high energy density. However, little success has been made in adopting Li metal anodes in sulfide electrolyte (SE)‐based ASSLMBs. The main challenges are the remarkable interfacial reactions and Li dendrite formation between Li metal and SEs. In this work, a solid‐state plastic crystal electrolyte (PCE) is engineered as an interlayer in SE‐based ASSLMBs. It is demonstrated that the PCE interlayer can prevent the interfacial reactions and lithium dendrite formation between SEs and Li metal. As a result, ASSLMBs with LiFePO₄ exhibit a high initial capacity of 148 mAh g^?1 at 0.1 C and 131 mAh g^?1 at 0.5 C (1 C = 170 mA g^?1), which remains at 122 mAh g^?1 after 120 cycles at 0.5 C. All‐solid‐state Li‐S batteries based on the polyacrylonitrile‐sulfur composite are also demonstrated, showing an initial capacity of 1682 mAh g^?1. The second discharge capacity of 890 mAh g^?1 keeps at 775 mAh g^?1 after 100 cycles. This work provides a new avenue to address the interfacial challenges between Li metal and SEs, enabling the successful adoption of Li metal in SE‐based ASSLMBs with high energy density.