Reconstruction of Conformal Nanoscale MnO on Graphene as a High‐Capacity and Long‐Life Anode Material for Lithium Ion Batteries

To tackle the issue of inferior cycle stability and rate capability for MnO anode materials in lithium ion batteries, a facile strategy is explored to prepare a hybrid material consisting of MnO nanocrystals grown on conductive graphene nanosheets. The prepared MnO/graphene hybrid anode exhibits a reversible capacity as high as 2014.1 mAh g^?1 after 150 discharge/charge cycles at 200 mA g^?1, excellent rate capability (625.8 mAh g^?1 at 3000 mA g^?1), and superior cyclability (843.3 mAh g^?1 even after 400 discharge/charge cycles at 2000 mA g^?1 with only 0.01% capacity loss per cycle). The results suggest that the reconstruction of the MnO/graphene electrodes is intrinsic due to conversion reactions. A long‐term stable nanoarchitecture of graphene‐supported ultrafine manganese oxide nanoparticles is formed upon cycling, which yields a long‐life anode material for lithium ion batteries. The lithiation and delithiation behavior suggests that the further oxidation of Mn(II ) to Mn(IV ) and the interfacial lithium storage upon cycling contribute to the enhanced specific capacity. The excellent rate capability benefits from the presence of conductive graphene and a short transportation length for both lithium ions and electrons. Moreover, the as‐formed hybrid nanostructure of MnO on graphene may help achieve faster kinetics of conversion reactions.     

Ever‐Increasing Pseudocapacitance in RGO–MnO–RGO Sandwich Nanostructures for Ultrahigh‐Rate Lithium Storage

Lithium ion batteries have attained great success in commercialization owing to their high energy density. However, the relatively delaying discharge/charge severely hinders their high power applications due to intrinsically diffusion‐controlled lithium storage of the electrode. This study demonstrates an ever‐increasing surface redox capacitive lithium storage originating from an unique microstructure evolution during cycling in a novel RGO–MnO–RGO sandwich nanostructure. Such surface pseudocapacitance is dynamically in equilibrium with diffusion‐controlled lithium storage, thereby achieving an unprecedented rate capability (331.9 mAh g^?1 at 40 A g^?1, 379 mAh g^?1 after 4000 cycles at 15 A g^?1) with outstanding cycle stability. The dynamic combination of surface and diffusion lithium storage of electrodes might open up possibilities for designing high‐power lithium ion batteries.     

Bamboo‐Like Hollow Tubes with MoS2/N‐Doped‐C Interfaces Boost Potassium‐Ion Storage

Potassium‐ion batteries (KIBs) are new‐concept of low‐cost secondary batteries, but the sluggish kinetics and huge volume expansion during cycling, both rooted in the size of large K ions, lead to poor electrochemical behavior. Here, a bamboo‐like MoS₂/N‐doped‐C hollow tubes are presented with an expanded interlayer distance of 10 Å as a high‐capacity and stable anode material for KIBs. The bamboo‐like structure provides gaps along axial direction in addition to inner cylinder hollow space to mitigate the strains in both radial and vertical directions that ultimately leads to a high structural integrity for stable long‐term cycling. Apart from being a constituent of the interstratified structure the N‐doped‐C layers weave a cage to hold the potassiation products (polysulfide and the Mo nanoparticles) together, thereby effectively hindering the continuing growth of solid electrolyte interphase in the interior of particles. The density functional theory calculations prove that the MoS₂/N‐doped‐C atomic interface can provide an additional attraction toward potassium ion. As a result, it delivers a high capacity at a low current density (330 mAh g^?1 at 50 mA g^?1 after 50 cycles) and a high‐capacity retention at a high current density (151 mAh g^?1 at 500 mA g^?1 after 1000 cycles).     

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.     

Layered P2‐Type K0.65Fe0.5Mn0.5O2 Microspheres as Superior Cathode for High‐Energy Potassium‐Ion Batteries

Potassium‐ion batteries have been regarded as the potential alternatives to lithium‐ion batteries (LIBs) due to the low cost, earth abundance, and low potential of K (?2.936 vs standard hydrogen electrode (SHE)). However, the lack of low‐cost cathodes with high energy density and long cycle life always limits its application. In this work, high‐energy layered P2‐type hierarchical K_0.65Fe_0.5Mn_0.5O₂ (P2‐KFMO) microspheres, assembled by the primary nanoparticles, are fabricated via a modified solvent‐thermal method. Benefiting from the unique microspheres with primary nanoparticles, the K⁺ intercalation/deintercalation kinetics of P2‐KFMO is greatly enhanced with a stabilized cathodic electrolyte interphase on the cathode. The P2‐KFMO microsphere presents a highly reversible potassium storage capacity of 151 mAh g^?1 at 20 mA g^?1, fast rate capability of 103 mAh g^?1 at 100 mA g^?1, and long cycling stability with 78% capacity retention after 350 cycles. A full cell with P2‐KFMO microspheres as cathode and hard carbon as anode is constructed, which exhibits long‐term cycling stability (>80% of retention after 100 cycles). The present high‐performance P2‐KFMO microsphere cathode synthesized using earth‐abundant elements provides a new cost‐effective alternative to LIBs for large‐scale energy storage.     

Nitrogen‐Doped Graphene Ribbon Assembled Core–Sheath MnO@Graphene Scrolls as Hierarchically Ordered 3D Porous Electrodes for Fast and Durable Lithium Storage

Graphene scroll is an emerging 1D tubular form of graphitic carbon that has potential applications in electrochemical energy storage. However, it still remains a challenge to composite graphene scrolls with other nanomaterials for building advanced electrode configuration with fast and durable lithium storage properties. Here, a transition‐metal‐oxide‐based hierarchically ordered 3D porous electrode is designed based on assembling 1D core–sheath MnO@N‐doped graphene scrolls with 2D N‐doped graphene ribbons. In the resulting architecture, porous MnO nanowires confined in tubular graphene scrolls are mechanically isolated but electronically well‐connected, while the interwoven graphene ribbons offer continuous conductive paths for electron transfer in all directions. Moreover, the elastic graphene scrolls together with enough internal voids are able to accommodate the volume expansion of the enclosed MnO. Because of these merits, the as‐built electrode manifests ultrahigh rate capability (349 mAh g^?1 at 8.0 A g^?1; 205 mAh g^?1 at 15.0 A g^?1) and robust cycling stability (812 mAh g^?1 remaining after 1000 cycles at 2.0 A g^?1) and is the most efficient MnO‐based anode ever reported for lithium‐ion batteries. This unique multidimensional and hierarchically ordered structure design is believed to hold great potential in generalizable synthesis of graphene scrolls composited with oxide nanowires for mutifuctional energy storage.     

Few‐Layer MoSe2 Nanosheets with Expanded (002) Planes Confined in Hollow Carbon Nanospheres for Ultrahigh‐Performance Na‐Ion Batteries

Sodium‐ion batteries (SIBs) are considered as a promising alternative to lithium‐ion batteries, due to the abundant reserves and low price of Na sources. To date, the development of anode materials for SIBs is still confronted with many serious problems. In this work, encapsulation‐type structured MoSe₂@hollow carbon nanosphere (HCNS) materials assembled with expanded (002) planes few‐layer MoSe₂ nanosheets confined in HCNS are successfully synthesized through a facile strategy. Notably, the interlayer spacing of the (002) planes is expanded to 1.02 nm, which is larger than the intrinsic value of pristine MoSe₂ (0.64 nm). Furthermore, the few‐layer nanosheets are space‐confined in the inner cavity of the HCNS, forming hybrid MoSe₂@HCNS structures. When evaluated as anode materials for SIBs, it shows excellent rate capabilities, ultralong cycling life with exceptional Coulombic efficiency even at high current density, maintaining 501 and 471 mA h g^?1 over 1000 cycles at 1 and 3 A g^?1, respectively. Even when cycled at current densities as high as 10 A g^?1, a capacity retention of 382 mA h g^?1 can be achieved. The expanded (002) planes, 2D few‐layer nanosheets, and unique carbon shell structure are responsible for the ultralong cycling and high rate performance.     

Temperature‐Mediated Engineering of Graphdiyne Framework Enabling High‐Performance Potassium Storage

Graphdiyne (GDY), an emerging type of carbon allotropes, possesses fascinating electrical, chemical, and mechanical properties to readily spark energy applications in the realm of Li‐ion and Na‐ion batteries. Nevertheless, rational design of GDY architectures targeting advanced K‐ion storage has rarely been reported to date. Herein, the first example of synthesizing GDY frameworks in a scalable fashion to realize superb potassium storage for high‐performance K‐ion battery (KIB) anodes is showcased. To begin with, first principles calculations provide theoretical guidances for analyzing the intrinsic potassium storage capability of GDY. Meanwhile, the specific capacity is predicted to be as high as 620 mAh g^?1, which is considerably augmented as compared with graphite (278 mAh g^?1). Experimental tests then reveal that prepared GDY framework indeed harvests excellent electrochemical performance as a KIB anode, achieving high specific capacity (≈505 mAh g^?1 at 50 mA g^?1), outstanding rate performance (150 mAh g^?1 at 5000 mA g^?1) and favorable cycling stability (a high capacity retention of over 90% after 2000 cycles at 1000 mA g^?1). Furthermore, kinetic analysis reveals that capacitive effect mainly accounts for the K‐ion storage, with operando Raman spectroscopy/ex situ X‐ray photoelectron spectroscopy identifying good electrochemical reversibility of GDY.     

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.     

A Composite of Carbon‐Wrapped Mo2C Nanoparticle and Carbon Nanotube Formed Directly on Ni Foam as a High‐Performance Binder‐Free Cathode for Li‐O2 Batteries

Cathode design is indispensable for building Li‐O₂ batteries with long cycle life. A composite of carbon‐wrapped Mo₂C nanoparticles and carbon nanotubes is prepared on Ni foam by direct hydrolysis and carbonization of a gel composed of ammonium heptamolybdate tetrahydrate and hydroquinone resin. The Mo₂C nanoparticles with well‐controlled particle size act as a highly active oxygen reduction reactions/oxygen evolution reactions (ORR/OER) catalyst. The carbon coating can prevent the aggregation of the Mo₂C nanoparticles. The even distribution of Mo₂C nanoparticles results in the homogenous formation of discharge products. The skeleton of porous carbon with carbon nanotubes protrudes from the composite, resulting in extra voids when applied as a cathode for Li‐O₂ batteries. The batteries deliver a high discharge capacity of ≈10 400 mAh g^?1 and a low average charge voltage of ≈4.0 V at 200 mA g^?1. With a cutoff capacity of 1000 mAh g^?1, the Li‐O₂ batteries exhibit excellent charge–discharge cycling stability for over 300 cycles. The average potential polarization of discharge/charge gaps is only ≈0.9 V, demonstrating the high ORR and OER activities of these Mo₂C nanoparticles. The excellent cycling stability and low potential polarization provide new insights into the design of highly reversible and efficient cathode materials for Li‐O₂ batteries.     

Facile Preparation of High‐Content N‐Doped CNT Microspheres for High‐Performance Lithium Storage

Herein, high‐content N‐doped carbon nanotube (CNT) microspheres (HNCMs) are successfully synthesized through simple spray drying and one‐step pyrolysis. HNCM possesses a hierarchically porous architecture and high‐content N‐doping. In particular, HNCM800 (HNCM pyrolyzed at 800 °C) shows high nitrogen content of 12.43 at%. The porous structure derived from well‐interconnected CNTs not only offers a highly conductive network and blocks diffusion of soluble lithium polysulfides (LiPSs) in physical adsorption, but also allows sufficient sulfur infiltration. The incorporation of N‐rich CNTs provides strong chemical immobilization for LiPSs. As a sulfur host for lithium–sulfur batteries, good rate capability and high cycling stability is achieved for HNCM/S cathodes. Particularly, the HNCM800/S cathode delivers a high capacity of 804 mA h g^?1 at 0.5 C after 1000 cycles corresponding to low fading rate (FR) of only 0.011% per cycle. Remarkably, the cathode with high sulfur loading of 6 mg cm^?2 still maintains high cyclic stability (capacity of 555 mA h g^?1 after 1000 cycles, FR 0.038%). Additionally, CNT/Co₃O₄ microspheres are obtained by the oxidation of CNTs/Co in the air. The as‐prepared CNT/Co₃O₄ microspheres are employed as an anode for lithium‐ion batteries and present excellent cycling performance.     

Stable Cycling of Phosphorus Anode for Sodium‐Ion Batteries through Chemical Bonding with Sulfurized Polyacrylonitrile

Sodium‐ion batteries are attracting increasing interests as a promising alternative to lithium‐ion batteries due to the abundant resource and low cost of sodium. Despite phosphorus (P) has extremely high theoretical capacity of 2595 mAh g^?1, its wide application for sodium‐ion battery is highly hampered by its fast capacity fading and low Coulombic efficiency as a result of large volume change upon cycling. Herein, a robust phosphorus anode with long cycle life for sodium‐ion battery via hybridization with functional conductive polymer is presented. To this end, the polyacrylonitrile is first dehydrogenated by sulfur via a facile thermal treatment, forming a conductive main chain embedded with C–S–S moieties. This functional conductive polymer enables the formation of P? S bonds between phosphorus and functional conductive matrix, leading to a robust electrode that can accommodate the large volume change upon substantial volume change in cycling. Consequently, this hybrid anode delivers a high capacity of ≈1300 mAh g^?1 at a current density of 520 mA g^?1 with high Coulombic efficiency (>99%) and good cycling performance (91% capacity retention after 100 cycles).     

Lithium Accommodation in a Redox‐Active Covalent Triazine Framework for High Areal Capacity and Fast‐Charging Lithium‐Ion Batteries

The synthesis of a new type of redox‐active covalent triazine framework (rCTF) material, which is promising as an anode for Li‐ion batteries, is reported. After activation, it has a capacity up to ≈1190 mAh g^?1 at 0.5C with a current density of 300 mA g^?1 and a high cycling stability of over 1000 discharge/charge cycles with a stable Coulombic efficiency in an rCTF/Li half‐cell. This rCTF has a high rate performance, and at a charging rate of 20C with a current density of 12 A g^?1 and it functions well for over 1000 discharge/charge cycles with a reversible capacity of over 500 mAh g^?1. By electrochemical analysis and theoretical calculations, it is found that its lithium‐storage mechanism involves multi‐electron redox‐reactions at anthraquinone, triazine, and benzene rings by the accommodation of Li. The structural features and progressively increased structural disorder of the rCTF increase the kinetics of infiltration and significantly shortens the activation period, yielding fast‐charging Li‐ion half and full cells even at a high capacity loading.     

Covalently Tethered Polyoxometalate–Pyrene Hybrids for Noncovalent Sidewall Functionalization of Single‐Walled Carbon Nanotubes as High‐Performance Anode Material

A covalently tethered polyoxometalate (POM)–pyrene hybrid (Py–SiW₁₁) is utilized for the noncovalent functionalization of single‐walled carbon nanotubes (SWNTs). The resulting SWNTs/Py–SiW₁₁ nanocomposite shows that both SiW₁₁ and pyrene moieties could interact with SWNTs without causing any chemical decomposition. When used as anode material in lithium‐ion batteries, the SWNTs/Py–SiW₁₁ nanocomposite exhibits higher discharge capacities, and better rate capacity and cycling stability than the individual components. When the current density is 0.5 mA cm^?2, the nanocomposite exhibits the initial discharge capacity of 1569.8 mAh g^?1, and a high discharge capacity of 580 mAh g^?1 for up to 100 cycles.     

Few‐Layered SnS2 on Few‐Layered Reduced Graphene Oxide as Na‐Ion Battery Anode with Ultralong Cycle Life and Superior Rate Capability

Na‐ion Batteries have been considered as promising alternatives to Li‐ion batteries due to the natural abundance of sodium resources. Searching for high‐performance anode materials currently becomes a hot topic and also a great challenge for developing Na‐ion batteries. In this work, a novel hybrid anode is synthesized consisting of ultrafine, few‐layered SnS₂ anchored on few‐layered reduced graphene oxide (rGO) by a facile solvothermal route. The SnS₂/rGO hybrid exhibits a high capacity, ultralong cycle life, and superior rate capability. The hybrid can deliver a high charge capacity of 649 mAh g^?1 at 100 mA g^?1. At 800 mA g^?1 (1.8 C), it can yield an initial charge capacity of 469 mAh g^?1, which can be maintained at 89% and 61%, respectively, after 400 and 1000 cycles. The hybrid can also sustain a current density up to 12.8 A g^?1 (≈28 C) where the charge process can be completed in only 1.3 min while still delivering a charge capacity of 337 mAh g^?1. The fast and stable Na‐storage ability of SnS₂/rGO makes it a promising anode for Na‐ion batteries.     

A Robust Ion‐Conductive Biopolymer as a Binder for Si Anodes of Lithium‐Ion Batteries

Binders have been reported to play a key role in improving the cycle performance of Si anode materials of lithium‐ion batteries. In this study, the biopolymer guar gum (GG) is applied as the binder for a silicon nano­particle (SiNP) anode of a lithium‐ion battery for the first time. Due to the large number of polar hydroxyl groups in the GG molecule, a robust interaction between the GG binder and the SiNPs is achieved, resulting in a stable Si anode during cycling. More specifically, the GG binder can effectively transfer lithium ions to the Si surface, similarly to polyethylene oxide solid electrolytes. When GG is used as a binder, the SiNP anode can deliver an initial discharge capacity as high as 3364 mAh g^?1, with a Coulombic efficiency of 88.3% at the current density of 2100 mA g^?1, and maintain a capacity of 1561 mAh g^?1 after 300 cycles. The study shows that the electrochemical performance of the SiNP anode with GG binder is significantly improved compared to that of a SiNP anode with a sodium alginate binder, and it demonstrates that GG is a promising binder for Si anodes of lithium‐ion batteries.     

Ti3+ Self‐Doped Dark Rutile TiO2 Ultrafine Nanorods with Durable High‐Rate Capability for Lithium‐Ion Batteries

Dark‐colored rutile TiO₂ nanorods doped by electroconducting Ti³⁺ have been obtained uniformly with an average diameter of ≈7 nm, and have been first utilized as anodes in lithium‐ion batteries. They deliver a high reversible specific capacity of 185.7 mAh g^?1 at 0.2 C (33.6 mA g^?1) and maintain 92.1 mAh g^?1 after 1000 cycles at an extremely high rate 50 C with an outstanding retention of 98.4%. Notably, the coulombic efficiency of Ti³⁺–TiO₂ has been improved by approximately 10% compared with that of pristine rutile TiO₂, which can be mainly attributed to its prompt electron transfer because of the introduction of Ti³⁺. Again the synergetic merits are noticed when the promoted electronic conductivity is combined with a shortened Li⁺ diffusion length resulting from the ultrafine nanorod structure, giving rise to the remarkable rate capabilities and extraordinary cycling stabilities for applications in fast and durable charge/discharge batteries. It is of great significance to incorporate Ti³⁺ into rutile TiO₂ to exhibit particular electrochemical characteristics triggering an effective way to improve the energy storage properties.     

Hierarchical NiS2 Modified with Bifunctional Carbon for Enhanced Potassium‐Ion Storage

Potassium‐ion batteries (PIBs) are currently drawing increased attention as a promising alternative to lithium‐ion batteries (LIBs) owing to the abundant resource and low cost of potassium. However, due to the large ionic radius size of K⁺, electrode material that can stably maintain K⁺ insertion/deintercalation is still extremely inadequate, especially for anode material with a satisfactory reversible capacity. As an attempt, nitrogen/carbon dual‐doped hierarchical NiS₂ is introduced as the electrode material in PIBs for the first time. Considering that the introduction of the carbon layer effectively alleviates the volume expansion of the material itself, further improves the electronic conductivity, and finally accelerates the charge transfer of K⁺, not surprisingly, NiS₂ decorated with the bifunctional carbon (NiS₂@C@C) material electrode shows excellent potassium storage performances. When utilized as a PIB anode, it delivers a high reversible capacity of 302.7 mAh g^?1 at 50 mA g^?1 after 100 cycles. The first coulombic efficiency is 78.6% and rate performance is 151.2 mAh g^?1 at 1.6 A g^?1 of the NiS₂@C@C, which are also notable. Given such remarkable electrochemical properties, this work is expected to provide more possibilities for the reasonable design of advanced electrode materials for metal sulfide potassium ion batteries.     

Iron Fluoride–Carbon Nanocomposite Nanofibers as Free‐Standing Cathodes for High‐Energy Lithium Batteries

The development of low‐cost, high‐energy cathodes from nontoxic, broadly available resources is a big challenge for the next‐generation rechargeable lithium or lithium‐ion batteries. As a promising alternative to traditional intercalation‐type chemistries, conversion‐type metal fluorides offer much higher theoretical capacity and energy density than conventional cathodes. Unfortunately, these still suffer from irreversible structural degradation and rapid capacity fading upon cycling. To address these challenges, here a versatile and effective strategy is harnessed for the development of metal fluoride–carbon (C) nanocomposite nanofibers as flexible, free‐standing cathodes. By taking iron trifluoride (FeF₃) as a successful example, assembled FeF₃–C/Li cells with a high reversible FeF₃ capacity of 550 mAh g^?1 at 100 mA g^?1 (three times that of traditional cathodes, such as lithium cobalt oxide, lithium nickel cobalt aluminum oxide, and lithium nickel cobalt manganese oxide) and excellent stability (400+ cycles with little‐to‐no degradation) are demonstrated. The promising characteristics can be attributed to the nanoconfinement of FeF₃ nanoparticles, which minimizes the segregation of Fe and LiF upon cycling, the robustness of the electrically conductive C network and the prevention of undesirable reactions between the active material and the liquid electrolyte using the composite design and electrolyte selection.     

Optimization of Von Mises Stress Distribution in Mesoporous α‐Fe2O3/C Hollow Bowls Synergistically Boosts Gravimetric/Volumetric Capacity and High‐Rate Stability in Alkali‐Ion Batteries

Hollow structures are often used to relieve the intrinsic strain on metal oxide electrodes in alkali‐ion batteries. Nevertheless, one common drawback is that the large interior space leads to low volumetric energy density and inferior electric conductivity. Here, the von Mises stress distribution on a mesoporous hollow bowl (HB) is simulated via the finite element method, and the vital role of the porous HB structure on strain‐relaxation behavior is confirmed. Then, N‐doped‐C coated mesoporous α‐Fe₂O₃ HBs are designed and synthesized using a multistep soft/hard‐templating strategy. The material has several advantages: (i) there is space to accommodate strains without sacrificing volumetric energy density, unlike with hollow spheres; (ii) the mesoporous hollow structure shortens ion diffusion lengths and allows for high‐rate induced lithiation reactivation; and (iii) the N‐doped carbon nanolayer can enhance conductivity. As an anode in lithium‐ion batteries, the material exhibits a very high reversible capacity of 1452 mAh g^?1 at 0.1 A g^?1, excellent cycling stability of 1600 cycles (964 mAh g^?1 at 2 A g^?1), and outstanding rate performance (609 mAh g^?1 at 8 A g^?1). Notably, the volumetric specific capacity of composite electrode is 42% greater than that of hollow spheres. When used in potassium‐ion batteries, the material also shows high capacity and cycle stability.