Current-Dependent Lithium Metal Growth Modes in “Anode-Free” Solid-State Batteries at the Cu|LLZO Interface

Controlling the lithium growth morphology in lithium reservoir-free cells (RFCs), so-called “anode-free” solid-state batteries, is of key interest to ensure stable battery operation. Despite several benefits of RFCs like improved energy density and easier fabrication, issues during the charging of the cell hinder the transition from lithium metal batteries with a lithium reservoir layer to RFCs. In RFCs, the lithium metal anode is plated during the first charging step at the interface between a metal current collector and the solid electrolyte, which is prone to highly heterogeneous growth instead of the desired homogeneous film-like growth. Herein, the lithium morphology during the first charging step in RFCs is explored as a function of current density and current collector thickness. Using operando scanning electron microscopy, an increase in the lithium particle density is observed with increasing current density at the Cu|Li_6.25Al_0.25La₃Zr₂O₁₂ interface. This observation is then applied to improve the area coverage of lithium by pulsed plating. It is also shown that thin current collectors (d = 100 nm) are unsuited for RFCs, as lithium whiskers penetrate them, resulting in highly heterogeneous interfaces. This suggests the use of thicker metal layers (several µm) to mitigate whisker penetration and facilitate homogeneous lithium plating.     

Compact 3D Copper with Uniform Porous Structure Derived by Electrochemical Dealloying as Dendrite‐Free Lithium Metal Anode Current Collector

The development of lithium (Li) metal anodes Li metal batteries faces huge challenges such as uncontrolled Li dendrite growth and large volume change during Li plating/stripping, resulting in severe capacity decay and high safety hazards. A 3D porous copper (Cu) current collector as a host for Li deposition can effectively settle these problems. However, constructing a uniform and compact 3D porous Cu structure is still an enormous challenge. Herein, an electrochemical etching method for Cu–Zinc (Zn) alloy is reported to precisely engrave a 3D Cu structure with uniform, smooth, and compact porous network. Such a continuous structure endows 3D Cu excellent mechanical properties and high electrical conductivity. The uniform and smooth pores with a large internal surface area ensures well dispersed current density for homogeneous Li metal deposition and accommodation. A smooth and stable solid electrolyte interphase is formed and meanwhile Li dendrites and dead Li are effectively suppressed. The Li metal anode conceived 3D Cu current collector can stably cycle for 400 h under an Li plating/stripping capacity of 1 mA h cm^?2 and a current density of 1 mA cm^?2. The Li@3D Cu||LiFePO₄ full cells present excellent cycling and rate performances. The electrochemical dealloying is a robust method to construct 3D Cu current collectors for dendrite‐free Li metal anodes.     

3D Flexible Carbon Felt Host for Highly Stable Sodium Metal Anodes

Sodium (Na) metal, which possesses a high theoretical capacity and the lowest electrochemical potential, is regarded as a promising anode material for Na–metal batteries. However, both Na dendrite growth and large volume change in cycling have severely impeded its practical applications. This study demonstrates that a 3D flexible carbon (C) felt which is already commercialized in large‐scale can be employed as a host for prestoring Na via a melt infusion strategy, through which a Na/C composite anode is obtained. The resulting anode exhibits a stable voltage profile and a small hysteresis over 120 cycles in carbonate‐based electrolytes in symmetrical cells owing to the fact that the metallic Na is confined in a conductive carbon felt host, which increases the Na⁺ deposition sites to lower the effective current density and render a uniform Na nucleation, restricting the dimension change in electrochemical cycling. More importantly, effective inhibition of Na dendrite growth and large volume change is achieved. When coupled with a Na_0.67Ni_0.33Mn_0.67O₂ cathode, the Na/C composite demonstrates a good suitability in full cells. This work provides an alternative option for the fabrication of stable Na metal anodes, which is of great significance for the practical applications of Na metal anodes in high‐energy‐density batteries.     

On the Reversibility and Fragility of Sodium Metal Electrodes

Metallic sodium is receiving renewed interest as a battery anode material because the metal is earth‐abundant, inexpensive, and offers a high specific storage capacity (1166 mAh g^?1 at ?2.71 V vs the standard hydrogen potential). Unlike metallic lithium, the case for Na as the anode in rechargeable batteries has already been demonstrated on a commercial scale in high‐temperature Na||S and Na||NiCl₂ secondary batteries, which increases interest. The reversibility of room temperature sodium anodes is investigated in galvanostatic plating/stripping reactions using in situ optical visualization and galvanostatic polarization measurements. It is discovered that electronic disconnection of mossy metallic Na deposits (“orphaning”) is a dominant source of anode irreversibility in liquid electrolytes. The disconnection is shown by means of direct visualization studies to be triggered by a root‐breakage process during the stripping cycle. As a further step toward electrode designs that are able to accommodate the fragile Na deposits, electrodeposition of Na is demonstrated in nonplanar electrode architectures, which provide continuous and morphology agnostic access to the metal at all stages of electrochemical cycling. On this basis, nonplanar Na electrodes are reported, which exhibit exceptionally high levels of reversibility (Coulombic efficiency >99.6% for 1 mAh cm^?2 Na throughput) in room‐temperature, liquid electrolytes.     

High‐Capacity All‐Solid‐State Sodium Metal Battery with Hybrid Polymer Electrolytes

All‐solid‐state sodium metal batteries (SSMBs) are of great interest for their high theoretical capacity, nonflammability, and relatively low cost owing partially to the abundance of sodium recourses. However, it is challenging to fabricate SSMBs because compared with their counterparts, which contain lithium metal, sodium metal is mechanically softer and more reactive toward the electrolyte. Herein, the synthesis and electrochemical properties of newly designed sodium‐containing hybrid network solid polymer electrolytes (SPEs) and their application in SSMBs are reported. The hybrid network is synthesized by controlled crosslinking of octakis(3‐glycidyloxypropyldimethylsiloxy)octasilsesquioxane and amine‐terminated polyethylene glycol in existence with sodium perchlorate (NaClO₄). Plating and stripping experiments using symmetric cells show prolonged cycle life of the SPEs, >5150 and 3550 h at current density of 0.1 and 0.5 mA cm^?2, respectively. The results for the first time show that the SPE|sodium metal interface migrates into the SPE phase upon cycling. SSMBs fabricated with the hybrid SPE sandwiched between sodium metal anode and bilayered δ‐Na_xV₂O₅ cathode exhibit record‐high specific capacity for solid sodium‐ion batteries of 305 mAh g^?1 and excellent Coulombic efficiency. This work demonstrates that the hybrid network SPEs are promising for SSMB applications.     

N‐Doped Graphene Modified 3D Porous Cu Current Collector toward Microscale Homogeneous Li Deposition for Li Metal Anodes

Lithium metal is the most promising anode material for high‐energy‐density batteries due to its high specific capacity of 3860 mAh g^?1 and low reduction potential of ?3.04 V versus standard hydrogen electrode. However, huge volume change, safety concerns, and low efficiency impede the practical applications of Li metal anodes. Herein, it is shown that the nitrogen‐doped graphene modified 3D porous Cu (3DCu@NG) current collector can mitigate the above problems. The N‐doped graphene, coating on the surface of 3D current collector, not only contributes to a uniform Li⁺ flux, but also leads to a scattered distribution of electrons throughout the surface, finally contributing to a uniform Li deposition and the improved electrochemical performance. In addition, the continuously porous structure of 3DCu@NG provides a space for the metallic Li deposition and could effectually accommodate the volume expansion during cycling. As a result, the Li‐3DCu@NG anode exhibits a high areal capacity of 4 mAh cm^?2, a high Li utilization of ≈98%, and an ultralow voltage hysteresis of ≈19 mV. The multifunctional N‐doped graphene modified 3D porous current collector promisingly provides a strategy for safe and high‐energy lithium metal anodes.     

High-Areal-Capacity and Long-Cycle-Life All-Solid-State Lithium-Metal Battery by Mixed-Conduction Interface Layer

The rapid growth of lithium dendrites has seriously hindered the development and practical application of high-energy-density all-solid-state lithium metal batteries (ASSLMBs). Herein, a soft carbon (SC)-nano Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) (with high ionic conductivity and diffusion coefficient) mixed ionic and electronic conducting interface layer is designed to promote the rapid migration of Li⁺ at the interfacial layer, induce the uniform deposition of lithium metal on nanoscale (nano) LLZTO ion-conducting network inside the interface layer, effectively suppress the growth of lithium dendrites, and significantly improve the electrochemical performance of ASSLMBs. LiZrO₂@LiCoO₂(LZO@LCO)/Li₆PS₅Cl(LPSCl)-nano LLZTO/Li ASSLMB achieves high current density (12.5 mA cm⁻²), ultra-high areal capacity (15 mAh cm⁻², corresponding to LZO@LCO mass loadings of 111.11 mg cm⁻²), and ultra-long cycle life (20 000 cycles). Therefore, the introduction of SC-nano LLZTO mixed conducting interface layer can greatly improve the interfacial stability between solid-state electrolyte (SSE) and lithium metal anode to enable dendrite-free ASSLMBs.     

In Situ Generation of Artificial Solid‐Electrolyte Interphases on 3D Conducting Scaffolds for High‐Performance Lithium‐Metal Anodes

Rational structure design of the current collector along with further engineering of the solid‐electrolyte interphases (SEI) layer is one of the most promising strategies to achieve uniform Li deposition and inhibit uncontrolled growth of Li dendrites. Here, a Li₂S layer as an artificial SEI with high compositional uniformity and high lithium ion conductivity is in situ generated on the surface of the 3D porous Cu current collector to regulate homogeneous Li plating/stripping. Both simulations and experiments demonstrate that the Li₂S protective layer can passivate the porous Cu skeleton and balance the transport rate of lithium ions and electrons, thereby alleviating the agglomerated Li deposition at the top of the electrode or at the defect area of the SEI layer. As a result, the modified current collector exhibits long‐term cycling of 500 cycles at 1 mA cm^?2 and stable electrodeposition capabilities of 4 mAh cm^?2 at an ultrahigh current density of 4 mA cm^?2. Furthermore, full batteries (LiFePO₄ as cathode) paired with this designed 3D anode with only ≈200% extra lithium show superior stability and rate performance than the batteries paired with lithium foil (≈3000% extra lithium). These explorations provide new strategies for developing high‐performance Li metal anodes.     

Sodium Plating from Na‐β″‐Alumina Ceramics at Room Temperature,Paving the Way for Fast‐Charging All‐Solid‐State Batteries

All‐solid‐state batteries with an alkali metal anode have the potential to achieve high energy density. However, the onset of dendrite formation limits the maximum plating current density across the solid electrolyte and prevents fast charging. It is shown that the maximum plating current density is related to the interfacial resistance between the solid electrolyte and the metal anode. Due to their high ionic conductivity, low electronic conductivity, and stability against sodium metal, Na‐β″‐alumina ceramics are excellent candidates as electrolytes for room‐temperature all‐solid‐state batteries. Here, it is demonstrated that a heat treatment of Na‐β″‐alumina ceramics in argon atmosphere enables an interfacial resistance <10 Ω cm² and current densities up to 12 mA cm^?2 at room temperature. The current density obtained for Na‐β″‐alumina is ten times higher than that measured on a garnet‐type Li₇La₃Zr₂O₁₂ electrolyte under equivalent conditions. X‐ray photoelectron spectroscopy shows that eliminating hydroxyl groups and carbon contaminations at the interface between Na‐β″‐alumina and sodium metal is key to reach such values. By comparing the temperature‐dependent stripping/plating behavior of Na‐β″‐alumina and Li₇La₃Zr₂O₁₂, the role of the alkali metal in governing interface kinetics is discussed. This study provides new insights into dendrite formation and paves the way for fast‐charging all‐solid‐state batteries.     

Fabrication of Hybrid Silicate Coatings by a Simple Vapor Deposition Method for Lithium Metal Anodes

Lithium metal anodes are highly promising for next‐generation rechargeable batteries. However, implication of lithium metal anodes is hampered by the unstable electrochemical behavior. Herein, the fabrication of hermetic coatings of hybrid silicate on lithium metal surface using a simple vapor deposition technique under the ambient condition is reported. Such coatings consist of a “hard” inorganic moiety that helps to suppress lithium dendrites and a “soft” organic moiety that enhances the toughness. Lithium metal batteries, including Li–LiFePO₄ and Li–S batteries, made with such coated anodes show significantly improved lifetime. This work provides a simple yet effective approach to stabilize lithium metal anodes for high‐performance lithium metal batteries.     

Vertically Aligned Lithiophilic CuO Nanosheets on a Cu Collector to Stabilize Lithium Deposition for Lithium Metal Batteries

Uncontrollable dendrite growth hinders the direct use of a lithium metal anode in batteries, even though it has the highest energy density of all anode materials. Achieving uniform lithium deposition is the key to solving this problem, but it is hard to be realized on a planar electrode surface. In this study, a thin lithiophilic layer consisting of vertically aligned CuO nanosheets directly grown on a planar Cu current collector is prepared by a simple wet chemical reaction. The lithiophilic nature of the CuO nanosheets reduces the polarization of the electrode, ensuring uniform Li nucleation and continuous smooth Li plating, which is difficult to realize on the normally used lithiophobic Cu current collector surface. The integration of the grown CuO arrays and the Cu current collector guarantees good electron transfer, and moreover, the vertically aligned channels between the CuO nanosheets guarantee fast ion diffusion and reduce the local current density. As a result, a high Columbic efficiency of 94% for 180 cycles at a current density of 1 mA cm^?2 and a prolonged lifespan of a symmetrical cell (700 h at 0.5 mA cm^?2) can be easily achieved, showing a simple but effective way to realize Li metal‐based anode stabilization.     

3D Vertically Aligned Li Metal Anodes with Ultrahigh Cycling Currents and Capacities of 10 mA cm−2/20 mAh cm−2 Realized by Selective Nucleation within Microchannel Walls

Although metallic lithium is regarded as the “Holy Grail” for next‐generation rechargeable batteries due to its high theoretical capacity and low overpotential, the uncontrollable Li dendrite growth, especially under high current densities and deep plating/striping, has inhibited its practical application. Herein, a 3D‐printed, vertically aligned Li anode (3DP‐VALi) is shown to efficiently guide Li deposition via a “nucleation within microchannel walls” process, enabling a high‐performance, dendrite‐free Li anode. Moreover, the microchannels within the microwalls are beneficial for promoting fast Li⁺ diffusion, supplying large space for the accommodation of Li during the plating/stripping process. The high‐surface‐area 3D anode design enables high operating current densities and high areal capacities. As a result, the Li–Li symmetric cells using 3DP‐VALi demonstrate excellent electrochemical performances as high as 10 mA cm^?2/10 mAh cm^?2 for 1500 h and 5 mA cm^?2/20 mAh cm^?2 for 400 h, respectively. Additionally, the Li–S and Li–LiFePO₄ cells using 3DP‐VALi anodes present excellent cycling stability up to 250 and 800 cycles at a rate of 1 C, respectively. It is believed that these new findings could open a new window for dendrite‐free metal anode design and pave the way toward energy storage devices with high energy/power density.     

Metal Sulfide‐Decorated Carbon Sponge as a Highly Efficient Electrocatalyst and Absorbant for Polysulfide in High‐Loading Li2S Batteries

Owing to its high theoretical specific capacity (1166 mA h g^?1) and particularly its advantage to be paired with a lithium‐metal‐free anode, lithium sulfide (Li₂S) is regarded as a much safer cathode for next‐generation advanced lithium–sulfur (Li–S) batteries. However, the low conductivity of Li₂S and particularly the severe “polysulfide shuttle” of lithium polysulfide (LiPS) dramatically hinder their practical application in Li–S batteries. To address such issues, herein a bifuctional 3D metal sulfide‐decorated carbon sponge (3DTSC), which is constructed by 1D carbon nanowires cross‐linked with 2D graphene nanosheets with high conductivity and polar 0D metal sulfide nanodots with efficient electrocatalytic activity and strong chemical adsorption capability for LiPSs, is presented. Benefiting from the well‐designed multiscale, multidimensional 3D porous nanoarchitecture with high conductivity, and efficient electrocatalytic and absorption ability, the 3DTSC significantly mitigates LiPS shuttle, improves the utilization of Li₂S, and facilitates the transport of electrons and ions. As a result, even with a high Li₂S loading of 8 mg cm^?2, the freestanding 3DTSC‐Li₂S cathode without a polymer binder and metallic current collector delivers outstanding electrochemical performance with a high areal capacity of 8.44 mA h cm^?2.     

Frogspawn‐Coral‐Like Hollow Sodium Sulfide Nanostructured Cathode for High‐Rate Performance Sodium–Sulfur Batteries

Room‐temperature (RT) sodium–sulfur (Na–S) batteries are attractive cost‐effective platforms as the next‐generation energy storage systems by using all earth‐abundant resources as electrode materials. However, the slow kinetics of Na–S chemistry makes it hard to achieve high‐rate performance. Herein, a facile and scalable approach has been developed to synthesize hollow sodium sulfide (Na₂S) nanospheres embedded in a highly hierarchical and spongy conductive carbon matrix, forming an intriguing architecture similar to the morphology of frogspawn coral, which has shown great potential as a cathode for high‐rate performance RT Na–S batteries. The shortened Na‐ion diffusion pathway benefits from the hollow structures together with the fast electron transfer from the carbon matrix contributes to high electrochemical reactivity, leading to superior electrochemical performance at various current rates. At high current densities of 1.4 and 2.1 A g^?1, high initial discharge capacities of 980 and 790 mAh g^?1_sulfur can be achieved, respectively, with reversible capacities stabilized at 600 and 400 mAh g^?1_sulfur after 100 cycles. As a proof of concept, a Na‐metal‐free Na–S battery is demonstrated by pairing the hollow Na₂S cathode with tin‐based anode. This work provides guidance on rational materials design towards the success of RT high‐rate Na–S batteries.     

A Coaxial‐Interweaved Hybrid Lithium Metal Anode for Long‐Lifespan Lithium Metal Batteries

Lithium (Li) metal is one of the most promising anode materials to construct next‐generation rechargeable batteries owing to its ultrahigh theoretical capacity and the lowest electrochemical potential. Unfortunately, practical application of Li metal batteries is severely hindered by short lifespan and safety concerns caused by Li dendrite growth during cycling. Herein, a coaxial‐interweaved hybrid Li metal anode is proposed for dendrite inhibition that significantly improves the cycling stability of Li metal batteries. The hybrid Li metal anode is fabricated by Li composition into a 3D interweaved scaffold, where each fiber of the interwoven scaffold is composed of a conductive skeleton and a coaxial lithiophilic layer modified on the surface. The coaxial‐interweaved structure endows the hybrid anode with favored Li affinity to guide uniform Li deposition, sufficient channels for ion transportation and electron conduction, and enhanced stability during Li plating and stripping. Consequently, the hybrid Li metal anode affords high Coulombic efficiency over 98.5% for 750 cycles with dendrite‐free morphologies in half cells and improved capacity retention of 80.1% after 100 cycles in LiFePO₄ full cells. The innovative coaxial‐interweaved hybrid Li metal anode demonstrates multiscale design strategy from lithiophilic modification to scaffold construction and promises the prospect of Li metal batteries for future applications.     

Graphitic Carbon Nitride Induced Micro‐Electric Field for Dendrite‐Free Lithium Metal Anodes

Uncontrolled dendrites resulting from nonuniform lithium (Li) nucleation/growth and Li volume expansion during charging cause serious safety problems for Li anode‐based batteries. Here the coating of nickel foam with graphitic carbon nitride (g‐C₃N₄) to have a 3D current collector (g‐C₃N₄@Ni foam) for dendrite‐free Li metal anodes is reported. The lithiophilic g‐C₃N₄ coupled with the 3D framework is demonstrated to be highly effective for promoting the uniform deposition of Li and suppressing the formation of dendrites. Both density functional theory calculations and experimental studies indicate the formation of a micro‐electric field resulting from the tri‐s‐triazine units of g‐C₃N₄, which induces numerous Li nuclei during the initial nucleation stage, effectively guiding the following Li growth on the 3D Ni foam to be well distributed. Furthermore, the 3D porous framework is favorable for absorbing any volume change and stabilizing the solid–electrolyte interphase layer during repeated Li plating/stripping. As such, a Li metal anode based on the g‐C₃N₄@Ni foam has a remarkable electrochemical performance with a high Coulombic efficiency (98% retention after 300 cycles), an ultralong lifespan up to 900 h, as well as a low overpotential (<15 mV at 1.0 mA cm^?2) at a Li deposition of 9.0 mA h cm^?2.     

The Role of Interlayer Chemistry in Li‐Metal Growth through a Garnet‐Type Solid Electrolyte

Securing the chemical and physical stabilities of electrode/solid‐electrolyte interfaces is crucial for the use of solid electrolytes in all‐solid‐state batteries. Directly probing these interfaces during electrochemical reactions would significantly enrich the mechanistic understanding and inspire potential solutions for their regulation. Herein, the electrochemistry of the lithium/Li₇La₃Zr₂O₁₂‐electrolyte interface is elucidated by probing lithium deposition through the electrolyte in an anode‐free solid‐state battery in real time. Lithium plating is strongly affected by the geometry of the garnet‐type Li₇La₃Zr₂O₁₂ (LLZO) surface, where nonuniform/filamentary growth is triggered particularly at morphological defects. More importantly, lithium‐growth behavior significantly changes when the LLZO surface is modified with an artificial interlayer to produce regulated lithium depositions. It is shown that lithium‐growth kinetics critically depend on the nature of the interlayer species, leading to distinct lithium‐deposition morphologies. Subsequently, the dynamic role of the interlayer in battery operation is discussed as a buffer and seed layer for lithium redistribution and precipitation, respectively, in tailoring lithium deposition. These findings broaden the understanding of the electrochemical lithium‐plating process at the solid‐electrolyte/lithium interface, highlight the importance of exploring various interlayers as a new avenue for regulating the lithium‐metal anode, and also offer insight into the nature of lithium growth in anode‐free solid‐state batteries.     

Manipulating Molecular Structure and Morphology to Invoke High‐Performance Sodium Storage of Copper Phosphide

Copper is used as current collector in rechargeable ion batteries due to its outstanding electronic conductivity and low cost. The intrinsic inactivity of copper, however, makes it a poor candidate for an electrode material without further structural modification. To fully utilize its high electronic conductivity, herein, the incorporation of heterogeneous phosphorus combined with building a unique 3D hollow structure is proposed. The as‐prepared copper phosphide hollow nanocubes deliver a stable capacity of 325 mAh·g^?1 at 50 mA·g^?1 and fast charging and discharging via pseudocapacitance behavior. The outstanding electrochemical performance is attributed to the synergetic effects of high electronic conductivity of copper and the high sodium storage capability of phosphorus. In addition, this facile synthesis method is also easily scaled up for practical applications. Thus, copper phosphide is a promising anode material for sodium ion batteries.     

Building Lithiophilic Ion‐Conduction Highways on Garnet‐Type Solid‐State Li+ Conductors

The integration of highly conductive solid‐state electrolytes (SSEs) into solid‐state cells is still a challenge mainly due to the high impedance existing at the electrolyte/electrode interface. Although solid‐state garnet‐based batteries have been successfully assembled with the assistance of an intermediate layer between the garnet and the Li metal anode, the slow discharging/charging rates of the batteries inhibits practical applications, which require much higher power densities. Here, a crystalline sulfonated‐covalent organic framework (COF) thin layer is grown on the garnet surface via a simple solution process. It not only significantly improves the lithiophilicity of garnet electrolytes via the lithiation of the COF layer with molten Li, but also creates effective Li⁺ diffusion “highways” between the garnet and the Li metal anode. As a result, the interfacial impedance of symmetric solid‐state Li cells is significantly decreased and the cells can be operated at high current densities up to 3 mA cm^?2, which is difficult to achieve with current interfacial modification technologies for SSEs. The solid‐state Li‐ion batteries using LiFePO₄ cathodes, Li anodes, and COF‐modified garnet electrolytes thus exhibit a significantly improved rate capability.     

Heteroatom‐Doped Mesoporous Hollow Carbon Spheres for Fast Sodium Storage with an Ultralong Cycle Life

Carbon materials have attracted significant attention as anode materials for sodium ion batteries (SIBs). Developing a carbon anode with long‐term cycling stability under ultrahigh rate is essential for practical application of SIBs in energy storage systems. Herein, sulfur and nitrogen codoped mesoporous hollow carbon spheres are developed, exhibiting high rate performance of 144 mA h g^?1 at 20 A g^?1, and excellent cycling durability under ultrahigh current density. Interestingly, during 7000 cycles at a current density of 20 A g^?1, the capacity of the electrode gradually increases to 180 mA h g^?1. The mechanisms for the superior electrochemical performance and capacity improvement of the cells are studied by electrochemical tests, ex situ transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Raman analysis of fresh and cycled electrodes. The unique and robust structure of the material can enhance transport kinetics of electrons and sodium ions, and maintain fast sodium storage from the capacitive process under high rate. The self‐rearrangement of the carbon structure, induced by continuous discharge and charge, lead to the capacity improvement with cycles. These results demonstrate a new avenue to design advanced anode materials for SIBs.