High‐Performance,Low‐Cost,and Dense‐Structure Electrodes with High Mass Loading for Lithium‐Ion Batteries

Lithium‐ion batteries have undergone a remarkable development in the past 30 years. However, conventional electrodes are insufficient for the ever‐increasing demand of high‐energy batteries. Here, reported is a thick electrode with a dense structure, as an alternative to the commonly recognized porous framework. A low‐temperature sintering technology with the aid of aqueous solvent, high pressure, and an ion‐conductive additive is originally developed for preparing the LiCoO₂ (LCO)/Li₄Ti₅O₁₂ (LTO) dense‐structure electrode as the representative cathode/anode material. The 400 µm thick cathode with 110 mg cm^?2 mass loading achieves a high specific capacity of 131.2 mAh g^?1 with a good capacity retention of 96% over 150 cycles, far exceeding the commercial counterpart (≈40 µm) of 54.1 mAh g^?1 with 39%. The ultrathick electrode of 1300 µm thickness presents a remarkable area capacity of 28.6 mAh cm^?2 that is 16 times that of the commercial electrode. The full cell based on the dense electrodes delivers an extremely high areal capacity of 14.4 mAh cm^?2. The ion‐diffusion coefficients of the densely sintered electrodes increase by nearly three orders of magnitude. This design opens up a new avenue for scalable and sustainable material manufacturing towards various practical applications.     

Intercalated Electrolyte with High Transference Number for Dendrite‐Free Solid‐State Lithium Batteries

Solid‐state lithium (Li) batteries using solid electrolytes and Li anodes are highly desirable because of their high energy densities and intrinsic safety. However, low ambient‐temperature conductivity and poor interface compatibility of solid electrolytes as well as Li dendrite formation cause large polarization and poor cycling stability. Herein, a high transference number intercalated composite solid electrolyte (CSE) is prepared by the combination of a solution‐casting and hot‐pressing method using layered lithium montmorillonite, poly(ethylene carbonate), lithium bis(fluorosulfonyl)imide, high‐voltage fluoroethylene carbonate additive, and poly(tetrafluoroethylene) binder. The electrolyte presents high ionic conductivity (3.5 × 10^?4 S cm^?1), a wide electrochemical window (4.6 V vs Li⁺/Li), and high ionic transference number (0.83) at 25 °C. In addition, a 3D Li anode is also fabricated via a facile thermal infusion strategy. The synergistic effect of high transference number intercalated electrolyte and 3D Li anode is more favorable to suppress Li dendrites in a working battery. The solid‐state batteries based on LiFePO₄ (Al₂O₃ @ LiNi_0.5Co_0.2Mn_0.3O₂), CSE, and 3D Li deliver admirable cycling stability with discharge capacity 145.9 mAh g^?1 (150.7 mAh g^?1) and capacity retention 91.9% after 200 cycles at 0.5 C (92.0% after 100 cycles at 0.2 C) at 25 °C. This work affords a splendid strategy for high‐performance solid‐state battery.     

Dual‐Salt Mg‐Based Batteries with Conversion Cathodes

Mg batteries as the most typical multivalent batteries are attracting increasing attention because of resource abundance, high volumetric energy density, and smooth plating/stripping of Mg anodes. However, current limitations for the progress of Mg batteries come from the lack of high voltage electrolytes and fast Mg‐insertable structure prototypes. In order to improve their energy or power density, hybrid systems combining Li‐driven cathode reaction with Mg anode process appear to be a potential solution by bypassing the aforementioned limitations. Here, FeS _x (x = 1 or 2) is employed as conversion cathode with 2–4 electron transfers to achieve a maximum energy density close to 400 Wh kg^?1, which is comparable with that of Li‐ion batteries but without serious dendrite growth and polysulphide dissolution. In situ formation of solid electrolyte interfaces on both sulfide and Mg electrodes is likely responsible for long‐life cycling and suppression of S‐species passivation at Mg anodes. Without any decoration on the cathode, electrolyte additive, or anode protection, a reversible capacity of more than 200 mAh g^?1 is still preserved for Mg/FeS₂ after 200 cycles.     

A Lithium‐Sulfur Battery with a High Areal Energy Density

The battery community has recently witnessed a considerable progress in the cycle lives of lithium‐sulfur (Li‐S) batteries, mostly by developing the electrode structures that mitigate fatal dissolution of lithium polysulfides. Nonetheless, most of the previous successful demonstrations have been based on limited areal capacities. For realistic battery applications, however, the chronic issues from both the anode (lithium dendrite growth) and the cathode (lithium polysulfide dissolution) need to be readdressed under much higher loading of sulfur active material. To this end, the current study integrates the following three approaches in a systematic manner: 1) the sulfur electrode material with diminished lithium polysulfide dissolution by the covalently bonded sulfur‐carbon microstructure, 2) mussel‐inspired polydopamine coating onto the separator that suppresses lithium dendrite growth by wet‐adhesion between the separator and Li metal, and 3) addition of cesium ions (Cs⁺) to the electrolyte to repel incoming Li ions and thus prevent Li dendrite growth. This combined strategy resolves the long‐standing problems from both electrodes even under the very large sulfur‐carbon composite loading of 17 mg cm^?2 in the sulfur electrode, enabling the highest areal capacity (9 mAh cm^?2) to date while preserving stable cycling performance.     

Fluoroethylene Carbonate Additives to Render Uniform Li Deposits in Lithium Metal Batteries

Lithium (Li) metal has been considered as an important substitute for the graphite anode to further boost the energy density of Li‐ion batteries. However, Li dendrite growth during Li plating/stripping causes safety concern and poor lifespan of Li metal batteries (LMB). Herein, fluoroethylene carbonate (FEC) additives are used to form a LiF‐rich solid electrolyte interphase (SEI). The FEC‐induced SEI layer is compact and stable, and thus beneficial to obtain a uniform morphology of Li deposits. This uniform and dendrite‐free morphology renders a significantly improved Coulombic efficiency of 98% within 100 cycles in a Li | Cu half‐cell. When the FEC‐protected Li metal anode matches a high‐loading LiNi_0.5Co_0.2Mn_0.3O₂ (NMC) cathode (12 mg cm^?2), a high initial capacity of 154 mAh g^?1 (1.9 mAh cm^?2) at 180.0 mA g^?1 is obtained. This LMB with conversion‐type Li metal anode and intercalation‐type NMC cathode affords an emerging energy storage system to probe the energy chemistry of Li metal protection and demonstrates the material engineering of batteries with very high energy density.     

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.     

Creating Effective Nanoreactors on Carbon Nanotubes with Mechanochemical Treatments for High‐Areal‐Capacity Sulfur Cathodes and Lithium Anodes

Li‐S batteries can potentially deliver high energy density and power, but polysulfide shuttle and lithium dendrite formations on Li metal anode have been the major hurdle. The polysulfide shuttle becomes severe particularly when the areal loading of the active material (sulfur) is increased to deliver the high energy density and the charge/discharge current density is raised to deliver high power. This study reports a novel mechanochemical method to create trenches on the surface of carbon nanotubes (CNTs) in free‐standing 3D porous CNT sponges. Unique spiral trenches are created by pressures during the chemical treatment process, providing polysulfide‐philic surfaces for cathode and lithiophilic surfaces for anode. The Li‐S cells made from manufacturing‐friendly sulfur‐sandwiched cathodes and lithium‐infused anodes using the mechanochemically treated electrodes exhibit a strikingly high areal capacity as high as 13.3 mAh cm^?2, which is only marginally reduced even with a tenfold increase in current density (16 mA cm^?2), demonstrating both high “cell‐level” energy density and power. The outstanding performance can be attributed to the significantly improved reaction kinetics and lowered overpotentials coming from the reduced interfacial resistance and charge transfer resistance at both cathodes and anodes. The trench–wall CNT sponge simultaneously tackles the most critical problems on both the cathodes and anodes of Li‐S batteries, and this method can be utilized in designing new electrode materials for energy storage and beyond.     

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.     

Sodium Storage Behavior in Natural Graphite using Ether‐based Electrolyte Systems

This work reports that natural graphite is capable of Na insertion and extraction with a remarkable reversibility using ether‐based electrolytes. Natural graphite (the most well‐known anode material for Li–ion batteries) has been barely studied as a suitable anode for Na rechargeable batteries due to the lack of Na intercalation capability. Herein, graphite is not only capable of Na intercalation but also exhibits outstanding performance as an anode for Na ion batteries. The graphite anode delivers a reversible capacity of ≈150 mAh g^?1 with a cycle stability for 2500 cycles, and more than 75 mAh g^?1 at 10 A g^?1 despite its micrometer‐size (≈100 μm). An Na storage mechanism in graphite, where Na⁺‐solvent co‐intercalation occurs combined with partial pseudocapacitive behaviors, is revealed in detail. It is demonstrated that the electrolyte solvent species significantly affect the electrochemical properties, not only rate capability but also redox potential. The feasibility of graphite in a Na full cell is also confirmed in conjunction with the Na_1.5VPO_4.8F_0.7 cathode, delivering an energy of ≈120 Wh kg^?1 while maintaining ≈70% of the initial capacity after 250 cycles. This exceptional behavior of natural graphite promises new avenues for the development of cost‐effective and reliable Na ion batteries.     

Hexafluoroisopropyl Trifluoromethanesulfonate-Driven Easily Li+ Desolvated Electrolyte to Afford Li||NCM811 Cells with Efficient Anode/Cathode Electrolyte Interphases

Solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI) with optimized components and structures are considered to be crucial for lithium-ion batteries. Here, gradient lithium oxysulfide (Li₂SO_x, x = 0, 3, 4)/uniform lithium fluoride (LiF)-type SEI is designed in situ by using hexafluoroisopropyl trifluoromethanesulfonate (HFPTf) as electrolyte additive. HFPTf is more likely to be reduced on the surface of Li anode in electrolytes due to its high reduction potential. Moreover, HFPTf can make Li⁺ desolvated easily, leading to the increase in the flux of Li⁺ on the surface of Li anode to avoid the growth of Li dendrites. Thus, the cycling stability of Li||Li symmetric cells is improved to be 1000 h at 0.5 mA cm⁻². In addition, HFPTf-contained electrolyte could make Li||NCM811 batteries with a capacity retention of 70% after 150 cycles at 100 mA g⁻¹, which is attributed to the formation of uniform and stable CEI on the cathode surface for hindering the dissolvation of metal ions from the cathode. This study provides effective insights on the strong ability of additives to adjust electrolytes in “one phase and two interphases” (electrolyte and SEI/CEI).     

Adiponitrile (C6H8N2): A New Bi‐Functional Additive for High‐Performance Li‐Metal Batteries

Rechargeable batteries with a Li metal anode and Ni‐rich Li[Ni_xCo_yMn_1?x?y]O₂ cathode (Li/Ni‐rich NCM battery) have been emerging as promising energy storage devices because of their high‐energy density. However, Li/Ni‐rich NCM batteries have been plagued by the issue of the thermodynamic instability of the Li metal anode and aggressive surface chemistry of the Ni‐rich cathode against electrolyte solution. In this study, a bi‐functional additive, adiponitrile (C₆H₈N₂), is proposed which can effectively stabilize both the Li metal anode and Ni‐rich NCM cathode interfaces. In the Li/Ni‐rich NCM battery, the addition of 1 wt% adiponitrile in 0.8 m LiTFSI + 0.2 M LiDFOB + 0.05 M LiPF₆ dissolved in EMC/FEC = 3:1 electrolyte helps to produce a conductive and robust Li anode/electrolyte interface, while strong coordination between Ni⁴⁺ on the delithiated Ni‐rich cathode and nitrile group in adiponitrile reduces parasitic reactions between the electrolyte and Ni‐rich cathode surface. Therefore, upon using 1 wt% adiponitrile, the Li/full concentration gradient Li[Ni_0.73Co_0.10Mn_0.15Al_0.02]O₂ battery achieves an unprecedented cycle retention of 75% over 830 cycles under high‐capacity loading of 1.8 mAh cm^?2 and fast charge–discharge time of 2 h. This work marks an important step in the development of high‐performance Li/Ni‐rich NCM batteries with efficient electrolyte additives.     

Solvation Engineering Enables High-Voltage Lithium Ion and Metal Batteries Operating Under −50 and 80 °C

Extreme temperatures (<-20 °C or >50 °C) would seriously impair the performance of lithium batteries through deteriorating bulk ion transport and electrode interfaces. Here, a rational design of weak solvent and anti-solvent combination is presented for wide-temperature electrolytes. The weak solvent provides accelerated desolvation kinetics of Li⁺ around the anode region, while the anti-solvent not only functions as an antifreeze agent for smooth ion migration at low temperatures but also interacts with the weak solvent to boost the formation of ionic aggregates. The weak and anti-solvent electrolyte (WAE) exerts excellent compatibility with both lithium metal and graphite. Under −40 °C, Li anode delivers 98.5% Coulombic efficiency and graphite outputs capacity over 230 mAh g^-1. Lithium-ion/metal batteries by pairing graphite anode with LiCoO₂ cathode with a negative to positive capacity ratio of 0.75 can realize steady operation at −50 °C with an average coulombic efficiency of 99.9%. Lithium metal batteries with 4.2 mAh cm^-2 high LiCoO₂ cathode loading and 50 µm thin lithium anode deliver 73.8% capacity output at −40 °C. Besides, the cells are stable up to 80 °C with an average coulombic efficiency of 99.7%. This research demonstrates a relatively loose Li⁺ solvation environment in WAE systems and provides wide-temperature electrolyte for high-performance lithium ion and metal batteries.     

A Soft Lithiophilic Graphene Aerogel for Stable Lithium Metal Anode

The lithium metal anode is one of the most promising anodes for next‐generation high‐energy‐density batteries. However, the severe growth of Li dendrites and large volume expansion leads to rapid capacity decay and shortened lifetime, especially in high current density and high capacity. Herein, a soft 3D Au nanoparticles@graphene hybrid aerogel (Au? GA) as a lithiophilic host for lithium metal anode is proposed. The large surface area and interconnected conductive pathways of the Au? GA significantly decrease the local current density of the electrode, enabling uniform Li deposition. Furthermore, the 3D porous structure effectively accommodates the large volume expansion during Li plating/stripping, and the Li_xAu alloy serves as a solid solution buffer layer to completely eliminate the Li nucleation over‐potential. Symmetric cells can stably cycle at 8 mA cm^?2 for 8 mAh cm^?2 and exhibit ultra‐long cycling: 1800 h at 2 mA cm^?2 for 2 mAh cm^?2, and 1200 h at 4 mA cm^?2 for 4 mAh cm^?2, with low over‐potential. Full cells assemble with a Cu@Au? GA? Li anode and LiFePO₄ cathode, can sustain a high rate of 8 C, and retain a high capacity of 59.6 mAh g^?1 after 1100 cycles at 2 C.     

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.     

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.     

Freestanding Metallic 1T MoS2 with Dual Ion Diffusion Paths as High Rate Anode for Sodium‐Ion Batteries

This work studies for the first time the metallic 1T MoS₂ sandwich grown on graphene tube as a freestanding intercalation anode for promising sodium‐ion batteries (SIBs). Sodium is earth‐abundant and readily accessible. Compared to lithium, the main challenge of sodium‐ion batteries is its sluggish ion diffusion kinetic. The freestanding, porous, hollow structure of the electrode allows maximum electrolyte accessibility to benefit the transportation of Na⁺ ions. Meanwhile, the metallic MoS₂ provides excellent electron conductivity. The obtained 1T MoS₂ electrode exhibits excellent electrochemical performance: a high reversible capacity of 313 mAh g^?1 at a current density of 0.05 A g^?1 after 200 cycles and a high rate capability of 175 mAh g^?1 at 2 A g^?1. The underlying mechanism of high rate performance of 1T MoS₂ for SIBs is the high electrical conductivity and excellent ion accessibility. This study sheds light on using the 1T MoS₂ as a novel anode for SIBs.     

Excellent Cycling Stability of Sodium Anode Enabled by a Stable Solid Electrolyte Interphase Formed in Ether‐Based Electrolytes

Sodium‐ion batteries have been considered one of the most promising power sources beyond Li‐ion batteries. Although the Na metal anode exhibits a high theoretical capacity of 1165 mAh g^?1, its application in Na batteries is largely hindered by dendrite growth and low coulombic efficiency. Herein, it is demonstrated that an electrolyte consisting of 1 m sodium tetrafluoroborate in tetraglyme can enable excellent cycling efficiency (99.9%) of a Na metal anode for more than 1000 cycles. This high reversibility of a Na anode can be attributed to a stable solid electrolyte interphase formed on the Na surface, as revealed by cryogenic transmission electron microscopy and X‐ray photoelectron spectroscopy (XPS). These electrolytes also enable excellent cycling stability of Na||hard‐carbon cells and Na||Na_2/3Co_1/3Mn_2/3O₂ cells at high rates with very high coulombic efficiencies.     

A Flexible 3D Multifunctional MgO‐Decorated Carbon Foam@CNTs Hybrid as Self‐Supported Cathode for High‐Performance Lithium‐Sulfur Batteries

One of the critical challenges to develop advanced lithium‐sulfur (Li‐S) batteries lies in exploring a high efficient stable sulfur cathode with robust conductive framework and high sulfur loading. Herein, a 3D flexible multifunctional hybrid is rationally constructed consisting of nitrogen‐doped carbon foam@CNTs decorated with ultrafine MgO nanoparticles for the use as advanced current collector. The dense carbon nanotubes uniformly wrapped on the carbon foam skeletons enhance the flexibility and build an interconnected conductive network for rapid ionic/electronic transport. In particular, a synergistic action of MgO nanoparticles and in situ N‐doping significantly suppresses the shuttling effect via enhanced chemisorption of lithium polysulfides. Owing to these merits, the as‐built electrode with an ultrahigh sulfur loading of 14.4 mg cm^?2 manifests a high initial areal capacity of 10.4 mAh cm^?2, still retains 8.8 mAh cm^?2 (612 mAh g^?1 in gravimetric capacity) over 50 cycles. The best cycling performance is achieved upon 800 cycles with an extremely low decay rate of 0.06% at 2 C. Furthermore, a flexible soft‐packaged Li‐S battery is readily assembled, which highlights stable electrochemical characteristics under bending and even folding. This cathode structural design may open up a potential avenue for practical application of high‐sulfur‐loading Li‐S batteries toward flexible energy‐storage devices.     

Tailored Redox Kinetics,Electronic Structures and Electrode/Electrolyte Interfaces for Fast and High Energy‐Density Potassium‐Organic Battery

Potassium‐organic batteries have a great potential for applications in large‐scale electricity grids and electric vehicles because of their low cost and sustainability. However, their inferior cycle stability and more importantly low energy density under fast discharge/charge process of organic cathodes limit their applications. This work introduces a simple polymerization processing which enables comprehensive tuning of redox kinetics, electronic structures, and electrode/electrolyte interfaces of the polymer cathodes. With this approach, a potassium‐organic battery with an impressive energy density of 113 Wh kg^?1 at a high power of 35.2 kW kg^?1 is shown which corresponds to a high current density of 147 C and a fully discharge within 10 s. The battery also has impressive cycling stability that a 100% Columbic efficiency is maintained and shows negligible capacity degradation after 1000 cycle at a high current density of 7.35 C. Using the polymer cathode and a dipotassium terephthalate anode, a full battery with superior energy density and cycling stability is demonstrated among all reported all‐organic full potassium ion batteries.     

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.