High-capacity Sodium-ion Batteries Research Articles

Biomass-derived hard carbon material for high-capacity sodium-ion battery anode through structure regulation

Economical and environmentally friendly hard carbon materials are attractive options for high-performance sodium-ion battery anode materials. Biomass-derived hard carbon materials have good economic benefits and environmentally friendliness as anode materials for sodium-ion batteries. In this work, we propose a new hard carbon material prepared from agricultural waste olive shells through a simple and environmentally friendly process. The effects of high-temperature treatments and pre-carbonization strategies on the pore structure and graphitization degree of the hard carbon materials were investigated. Combined with electrochemical performance tests, the influence of structural changes on the sodium storage properties of the olive shell-derived hard carbon was revealed. Under the optimized conditions of carbonization temperature and pre-carbonization strategy, the OSHC-Air electrode exhibits excellent sodium storage capacity with 87 % capacity remaining after 1000 cycles at 1000 mA g−1. The assembled PB//OSHC-Air sodium-ion full cell exhibits a high capacity of 216 mAh g−1. Our research provides a potential candidate for commercial anode materials for high-capacity sodium-ion batteries.

Suppression of Adverse Phase Transition of Layered Oxide Cathode via Local Electronic Structure Regulation for High-Capacity Sodium-Ion Batteries.

Advancing the high-voltage stability of the O3-type layered cathodes for sodium-ion batteries is critical to boost their progress in energy storage applications. However, this type of cathode often suffers from intricate phase transition and structural degradation at high voltages (i.e., >4.0 V vs Na+/Na), resulting in rapid capacity decay. Here, we present a Li/Ti cosubstitution strategy to modify the electronic configuration of oxygen elements in the O3-type layered oxide cathode. This deliberate modulation simultaneously mitigates the phase transitions and counteracts the weakening of the shielding effect resulting from the extraction of sodium ions, thus enhancing the electrostatic bonding within the TM layer and inducing and optimizing the O3-OP2 phase transition occurring in the voltage range of 2.0-4.3 V. Consequently, the cosubstituted NaLi1/9Ni1/3Mn4/9Ti1/9O2 exhibits an astounding capacity of 161.2 mAh g-1 in the voltage range of 2.0-4.3 V at 1C, and stable cycling up to 100 cycles has been achieved. This work shows the impact mechanism of element substitution on interlayer forces and phase transitions, providing a crucial reference for the optimization of O3-type materials.

Novel multiphase nano Ni3Bi2S2/NiS anchored on graphite nanosheet for high-capacity sodium-ion battery anodes

In the context of scalable electrode production via ball-milling, achieving high cycling stability and electrochemical performance in bifunctional anodes for sodium ion batteries (SIBs) is crucial yet remains a significant challenge. To address these objectives, we have developed a unique hybrid anode nanocomposite characterized by its local multiphase nature. This composite involves the incorporation of novel ternary-Ni-Bi-S/binary-Ni-S nanomaterials onto exfoliated graphite nanosheets (Ni3Bi2S2/NiS-G) through a facile ball-milling process. Our combined experimental and theoretical investigations suggest that the interactions between graphite nanosheets and the layered structure of Ni3Bi2S2/NiS, along with the discharge products of Na2S, play pivotal roles in enhancing the Na+ diffusion rate and stability of the hierarchical configuration anode. Upon testing, the novel Ni3Bi2S2/NiS-G shows overwhelmingly higher electrochemical performance compared to the Ni3Bi2S2/NiS counterpart, the Ni3Bi2S2/NiS-G delivered a reversible capacity of 489.9 mAh/g at 0.2 A/g after 400 cycles, and displayed a high capacity of 387.3 and 339.6 mAh/g after 500 cycles at 1 A/g and 2 A/g, respectively, yielding a high capacity retention ratio of 84.8 % and 82.8 % of the 1st cycle. This work provided a novel approach for developing new bifunctional anode electrodes with high capacity and rate performance as well as superior cycling stability.

Double additive electrolyte solvation engineering to achieve long cycle and high capacity sodium-ion battery

Sodium-ion batteries are a promising energy storage system due to their rich sodium resources and many other advantages. However, its development is severely hampered by the electrolyte's low compatibility with the electrode contact. Herein, we propose a solvation control strategy with ethoxy (pentafluoro) cyclotriphosphazene (PFPN) and NaClO4 double additives to reconstruct the solvation structure of sodium ions in electrolytes. This enables the electrolyte to form a dense and stable solid electrolyte interlayer (SEI) and double-layer cathode electrolyte interphase (CEI) on the surface of the electrode material to achieve long-cycle and high-capacity sodium-ion batteries. PFPN can form a stable SEI rich in inorganic components at the anode interface. ClO4- can first reach the cathode surface to create a NaCl and polymer-like chain CEI with sodium ions and solvents, and then the PFPN derivatives are migrated to the cathode surface to open the ring and decompose, thus forming a double-layer stable CEI. Therefore, the PEDN electrolyte can simultaneously improve the interface stability of the battery's cathode and anode solid electrolyte. Hence, the capacity retention rate of the 4.5 Ah Na3Fe2(PO4)P2O7 (NFP)||hard carbon (HC) pouch cell after 2500 cycles at 1C is 88.26%.

Robust pseudocapacitive Na+ intercalation induced by MoS2 on active Mo2C current collector interface for high areal capacity sodium-ion batteries

Sodium-ion batteries (SIBs) have emerged as compelling alternatives in the realm of electrochemical energy devices, poised to substitute lithium-ion batteries (LIBs). The primary challenge encompasses not only the scarcity of anode materials exhibiting exceptional Na+ storage capacity but also the endeavor to achieve high areal capacity. To address this challenge, a comprehensive strategy is proposed that entails utilizing a highly conductive molybdenum dicarbide (Mo2C) current collector (denoted as CCM) as a supporting scaffold for the bottom-up growth of molybdenum disulfide nanosheets (MoS2, serving as the main active component) (denoted as CCM@MoS2). The CCM improves interfacial bonding with MoS2 nanosheets and offers additional capacity to accommodate the increased Na+ insertion activity. Both theoretical and kinetic analyses reveal that the enhanced Na+ storage properties primarily stem from favorable adsorption energy, reduced diffusion barrier, and intercalation pseudocapacitance due to the strong electronic interfacial interaction between active CCM and MoS2. Hence, the as-prepared optimized CCM@MoS2 electrode exhibits a superior areal capacity of 6.36 mAh cm−2 at 0.4 mA cm−2, excellent rate capability of 1.02 mAh cm−2 at 24 mA cm−2 and long cycle life up to 500 cycles at 4 mA cm−2. Interesting, our as-prepared CCM@MoS2 electrode shows better performance for Na+ storage than Li+ storage at higher current density, affirming the enhanced kinetics in our architecture. This work proposes a rational strategy to enhance the areal capacity and stability of MoS2-based anode for SIBs and beyond.

Deciphering multistep transformation mechanism of cobalt-vanadium bimetallic sulfides anode in sodium storage

Transition metal sulfides as a high specific capacity sodium-ion batteries (SIBs) anode which have been suffering from successive phase transitions bringing about stress changes, poor electronic conductivity and ineffective ion transport kinetics. Combining self-sacrificial templates and ion-exchange transition reaction mechanisms, herein, cobalt, vanadium bimetallic sulfides hollow nano-cubic boxes with nitrogen-doped nanocarbon coating layer (CoV2S4@NC) are designed to solve these symbiosis problems. With a combination of in-situ Raman, ex-situ XPS/TEM, and density-functional theory calculations, the synergistically coordination mechanism between cobalt and vanadium binary metal during multi-step conversion processes is responsible for the faster charge transfer kinetics and boosted Na+ pseudocapacitance storage capability. Furthermore, the hollow cubic structure combined with the carbon shell layer can release the internal stress during phase transitions and avoid the recurrent growth of SEI film by volume change during the electrochemical process, thus realizing a superior electrode/electrolyte interface. Thus, when used as anode materials for SIBs, the prepared anode materials display excellent electrochemical performance, delivering capacity of 492 mA h g−1 at a current density of 10 A g−1 and high capacity stability with 484 mAh g−1 after 1000 cycles at 5 A g−1. More importantly, the assembled full cell (Na3V2(PO4)3//CoV2S4@NC) also shows high capacity of 574 mAh g−1 with 94.7% capacity retention after 85 cycles, suggesting the potential application of bimetallic sulfides in SIBs.

Design of Ion Channel Confined Binary Metal Cu-Fe Selenides for All-Climate, High-Capacity Sodium Ion Batteries.

Exploring special anode materials with high capacity, stable structure, and extreme temperature feasibility remains a great challenge in secondary sodium based energy systems. Here, a bimetallic Cu-Fe selenide nanosheet with refined nanostructure providing confined internal ion transport channels are reported, in which the structure improves the pseudocapacitance and reduces the charge transfer resistance for making a significant contribution to accelerating the reaction dynamics. The CuFeSe2 nanosheets have a high initial specific capacity of 480.4mAhg-1 at 0.25Ag-1, showing impressively excellent rate performance and ultralong cycling life over 1000 cycles with 261.1mAhg-1 at 2.5Ag-1. Meanwhile, it exhibits a good sodium storage performance at extreme temperatures from -20°C to 50°C, supporting at least 500 cycles. Besides, the CuFeSe2||Na3V2(PO4)3/C full cell delivers a high specific capacity of 168.5mAhg-1 at 0.5Ag-1 and excellent feasibility for over 600 cycles long cycling. Additionally, the Na+ storage mechanisms are further revealed by ex situ X-ray diffraction (XRD) and in situ transmission electron microscopy (TEM) techniques. A feasible channelized structural design strategy is provided that inspires new instruction into the development of novel materials with high structural stability and low volume expansion rate toward the application of other secondary batteries.

Facilitating Synthesis of FeP/C@CoP Composites as High-Performance Anode Materials for Sodium-Ion Batteries

Low-cost, high-capacity sodium-ion batteries can help solve energy shortages and various environmental problems. Transition metal phosphides have a high theoretical capacity and a relatively low redox potential (vs. Na/Na+) and are therefore expected to be used as anodes for sodium-ion batteries. Herein, a heterostructure of a FeP/C@CoP composite with a robust structure, fast charge transfer and abundant active sites was rationally designed and synthesized by growing a Co-ZIFs nanoarray on Fe-MOFs and using a phosphiding process. Using this facilitated and cost-effective method, the FeP/CoP bimetal phosphide heterostructures were uniformly embedded into the carbon matrix, and the capacity and cycle stability were effectively improved. The specific capacity of the FeP/C@CoP was as high as 275.7 mA h g−1 at a high current density of 5 A g−1, and it was still as high as 321.9 mA h g−1 after 800 cycles at a current density of 1 A g−1. Cyclic voltammetry was used to perform the kinetic analysis, and it was determined that the FeP/C@CoP exhibited an obvious pseudocapacitive behavior during the charge–discharge process of up to 87.4% at a scan rate of 1 mv s−1. This work provides a facilitated method of synthesizing composites that can realize a viable strategy for high-performance energy storage.

Multiphase nano Co9S8/CoS encapsulated in N-doped carbon for high capacity sodium-ion battery anode

As anode materials for sodium-ion batteries (SIBs), transition metal sulfides (TMSs) have been widely explored due to their low cost, high theoretical capacity and rich redox reactions. However, poor cycling performance and capacity retention limit the application of materials. In this work, multiphase nano Co9S8/CoS encapsulated in N-doped carbon for high capacity SIBs anode is prepared via a facile two-step strategy: precipitation and heat treatment. When applied as anodes for SIBs, mass capacity of 389.2 mAh g−1 at 0.1 A g−1 after 60 cycles is obtained, and delivered ~300 mAh g−1 from 2nd to 300th cycle without depravation under 1.0 A g−1. In addition, according to the calculation of Na+ diffusion kinetics, it is evident that carbon encapsulation not only helps prevent electrolyte erosion but also enhances the DNa+ of the anode material. The high efficient strategy can be applied to synthesis of other multiphase analogues. Based on theoretical investigations, calculations of band gaps and rebuild energies for other TMSs (i.e., Cu7S4/Cu2S, FeS/Fe21.333O32/Fe3O4, MnS2/MnS, Ni3S2/Ni3C and cubic-ZnS/hexagonal-ZnS), as well as analysis of cyclic data, it can be concluded that Co9S8/CoS@NC material exhibits the highest conductivity and cycle stability.

P2/O3 Biphasic Layered Oxide Heterojunction: A Cathode for High-Capacity Sodium-Ion Batteries

P2/O3 Biphasic Layered Oxide Heterojunction: A Cathode for High-Capacity Sodium-Ion Batteries

The Future of Energy Storage: Detailed Description of Layered Structure and Porosity of Hard Carbons

The effort of commissioning green and renewable energy with the growing list of critical raw materials demands innovations in energy storage and conversion [1]. The research on sodium-ion batteries (SIBs) has proved promising for large-scale stationary energy storage. Therefore, the crucial need for material research for SIB applications has motivated the studies on hard carbon anodes that have shown high reversible capacity and low working potential[2]. Nevertheless, the exact sodium storage mechanism in hard carbons remains uncertain, inspiring the detailed study of the structure of non-graphitized carbons. Yet, the structure of hard carbons has no long-range order, which complicates the exact characterization. Thus, we present a study focusing on the chemically activated hard carbons' porous and graphite-like structures with complementary wide- and small-angle scattering methods (Figure 1). The current presentation examines the exact impact of the ratio of activating agents on the structure of hard carbons and how the structure affects the ability to store sodium ions. The studied materials were synthesized from D-glycose via hydrothermal carbonization and activated with zinc chloride with different ratios[3]. The evaluation of the layered structure of carbons from wide-angle x-ray scattering (WAXS) data was carried out with Ruland and Smarsly algorithm[4], which is more suitable for non-graphitic carbons than the typically used approaches. The porous structure was described with small-angle neutron scattering (SANS) data model-free analysis, combining Schiller, Mering, Perret, and Ruland approaches[5].This presentation reveals exciting results from the detailed data analysis that opens new perspectives to the material development for SIB hard carbon anodes. During activation of the hard carbon materials activated with zinc chloride with ratios 1:1.5 and 1:2 significant differences in the interlayer arrangement, pore sizes, and the degree of disorder appeared. The presented results indicate the role of different structural parameters on the charge-discharge plateau and sloping regions, guiding to the better understanding of the sodium storage mechanism in hard carbon anode. The presentation demonstrates the interpretation of the results with a focus on improving energy storage capability. It is discussed: is the detailed structural analysis for the non-graphitic carbons a comprehensive and new sight into the future of energy storage?[1] Critical Raw Materials for Strategic Technologies and Sectors in the EU A Foresight Study, (2020).[2] A. Adamson, R. Väli, M. Paalo, J. Aruväli, M. Koppel, R. Palm, E. Hark, J. Nerut, T. Romann, E. Lust, A. Jänes, Peat-Derived Hard Carbons for High Capacity Sodium-Ion Batteries: Synthesis and Characterization, ECS Meet. Abstr., MA2020-02 (2020) 78.[3] M. Härmas, T. Thomberg, A. Jänes, Effect of Zinc Chloride Activation on D-Glucose Derived Carbons Based Capacitors Performance in Ionic Liquid, J. Electrochem. Soc., 167 (2020) 080533.[4] W. Ruland, B. Smarsly, X-ray scattering of non-graphitic carbon: an improved method of evaluation, J. Appl. Crystallogr., 35 (2002) 624–633.[5] E. Härk, M. Ballauff, Carbonaceous Materials Investigated by Small-Angle X-ray and Neutron Scattering, C, 6 (2020) 82. Figure 1

Pseudocapacitive sodium-ion storage in one-dimensionally structured anatase TiO2 nanofiber anode for high performance sodium-ion batteries

Nanofibers provide high surface area to volume ratio, vectoral conduction, fast ionic diffusion, and short pathways for sodium ions. Titania nanofibers exhibit excellent electrochemical performance when used for sodium-ion storage. One-dimensional titania nanofiber was synthesized by an electrospinning process as an anode material for high capacity sodium-ion batteries. The electrochemical kinetics of titania nanofiber for sodium-ion storage were examined. Titania nanofiber exhibited pseudocapacitive capacitive properties with high rate performance, giving capacity of 97 mA h g−1 after 1000 cycles with a current density of 1000 mA g−1. Even when current rate returned to the initial current density of 50 mA g−1, titania nanofiber electrode capacity climbed to 206 mA h g−1 again without capacity fading, which indicated good rate performance, superior sodium insertion/extraction reaction, and high reversible capacity.

Boosting sodium-ion storage performance by tailoring intragranular porous WS2/C nanocomposites anode

Two-dimensional layered semiconducting materials, such as tungsten disulfide, have attracted significant research interest over the past few decades. With rational optimization of their chemical constitutions and regulation of electronic configurations, these materials can achieve commercial viability. Herein, the WS2/C hybrid was constructed by organic amine intercalation and in-situ pyrolysis. Intraparticle porous WS2/C was successfully synthesized by dissolving and etching. The specific surface area of the obtained WS2/C was significantly enhanced on the removal of WO3 through alkali etching, which facilitated the Na-insertion/extraction. Therefore, the obtained porous WS2/C composite delivered a high reversible capacity and improved cycle stability with 346.3 mAh g−1 over 80 cycles at 100 mA g−1. This work proposes an intragranular porous WS2/C composite electrode design which shows a superior sodium storage performance, improved electronic conductivity and enhanced reversible specific capacity. It is expected to present a novel insight for designing other high-capacity sodium-ion and other alkaline ion battery electrode materials.

Understanding dehydration of Prussian white: from material to aqueous processed composite electrodes for sodium-ion battery application

Understanding dehydration of Prussian white systems to enable processability of water-based electrodes for sustainable and high capacity sodium-ion batteries.

Polycrystalline Fe- and Sn-based sulfides for high-capacity sodium-ion battery anodes.

Nano-polycrystalline Sn2S3/Sn3S4/FeS/Fe7S8 sulfides anchored on graphene were synthesized via annealing SnS2 and Fe followed by homogeneously combining them with exfoliated graphite. When applied as an anode for a sodium-ion battery, the reversible capacity reached 863 mA h g-1 at 100 mA g-1. This facial materials synthesis method may be applied in various fields.

Antimony Nanobelt Asymmetric Membranes for High Capacity Sodium Ion Battery Anodes

The standard lithium-ion battery (LIB) using graphite electrodes has become exceedingly important in today’s world. Everything from electric cars to solar energy storage systems need these batteries, and the capabilities and progress of these devices rely on the steady advancement of battery technology. However, lithium is a scarce resource and is projected to run out with the ever-increasing demand we are placing on it. For this reason, we are investigating sodium ion batteries (SIB) as an alternative to LIB.While many methods have been studied to improve SIB capacities and lifespans, our method stands out by using antimony nanobelts incorporated into an asymmetric membrane structure as a high performance anode material for SIB due to its theoretical capacity of 660 mAh g-1 compared to hard carbon-based SIB (300 mAh g-1). In addition to the asymmetric membrane structure, we use a carbon coating around the membrane which can further improve performance and stability. Embedding these group V nanomaterials within an asymmetric membrane structure coated in carbon will accommodate the large volume expansion of Sb-based SIB anode, enhance mechanical strength, and prevent rapid capacity loss due to leaching of cracked materials.Herein, we demonstrate that the capacity and the cycling performance of SIB can be significantly improved over not only current SIB but also LIB. Preliminary results indicate that Sb nanobelts incorporated into an asymmetric membrane exhibit increased performance as a sodium-ion battery anode compared to Sb nanoparticle membranes, furthermore, dip coating the asymmetric membranes with a carbon based solution increases both capacity and cycling performance compared to membranes with no extra carbon coating. The batteries made using the dip coated Sb nanobelt asymmetric membranes show a specific capacity between 630 and 650 mAh g-1 with a capacity retention of 99.4 percent over 45 cycles and an initial capacity loss of only 14 percent. In addition to electrochemical tests, we have also characterized the samples using scanning electron microscopy, energy dispersive x-ray spectroscopy, thermal gravimetric analysis, powder x-ray diffraction spectroscopy, and RAMAN spectroscopy to identify and quantify the materials in the membranes and starting materials. Using these characterizations, we were able to confirm the chemical composition and morphology of the Sb and C in our membranes. Thereby a scalable and cost-effective method of increasing capacity of NIB, while maintaining relatively good life cycle longevity has been developed by our research laboratory.

Constructing nitrogen-doped porous carbon immobilized Co9S8 composite as high-performance anode material for sodium-ion batteries

Transition metal sulfides (TMSs) as anode materials deliver promising potential in achieving high-capacity sodium-ion batteries (SIBs). But the undesirable volume change for structure upon redox process always hinder the realization of satisfactory cycling stability and rate capability. Herein, a novel Co9S8/carbon composite (Co9S8 @NPC) with Co9S8 nanoparticles (NPs) immobilized into nitrogen-doped porous carbon networks was synthesized via the successive procedures of sol-gel, pyrolysis carbonization and in situ sulfidation and employed as anode material for SIBs. By virtue of the yielded porous feature, nitrogen-doping and space confinement of Co9S8 NPs in conductive carbon sheet networks, the Co9S8 @NPC is able to offer integrated merits of sufficient active sites, improved reaction dynamics and rigid structural stability for high-performance Na-storage. As a result, the assembled Co9S8 @NPC electrode possesses large initial discharge/charge capacities (752.5/325.3 mAh g−1 at 50 mA g−1), considerable rate capability (138.5 mAh g−1 at 3000 mA g−1) and high cycling stability (275.3 mAh g−1 at 50 mA g−1 after 100 cycles; 120.4 mAh g−1 at 500 mA g−1 after 3000 cycles). In order to uncover the diffusion and storage mechanism of Na+ ions in the electrode material, pseudocapacitive behavior, reaction dynamics and related theoretical simulation based on first-principles calculations are initially conducted. The facile synthesis strategy and desirable Na-storage performance might enable the Co9S8 @NPC composite great potential in advanced SIBs.

Tailoring Ultrafast and High-Capacity Sodium Storage via Binding-Energy-Driven Atomic Scissors.

Controllably tailoring alloying anode materials to achieve fast charging and enhanced structural stability is crucial for sodium-ion batteries with high rate and high capacity performance, yet remains a significant challenge owing to the huge volume change and sluggish sodiation kinetics. Here, a chemical tailoring tool is proposed and developed by atomically dispersing high-capacity Ge metal into the rigid and conductive sulfide framework for controllable reconstruction of GeS bonds to synergistically realize high capacity and high rate performance for sodium storage. The integrated GeTiS3 material with stable Ti-S framework and weak GeS bonding delivers high specific capacities of 678 mA h g-1 at 0.3 C over 100 cycles and 209 mA h g-1 at 32 C over 10000 cycles, outperforming most of the reported alloying type anode materials for sodium storage. Interestingly, in situ Raman, X-ray diffraction (XRD), and ex situ transmission electron microscopy (TEM) characterizations reveal the formation of well-dispersed Nax Ge confined in the rigid Ti-S matrix with suppressed volume change after discharge. The synergistically coupled alloying-conversion and surface-dominated redox reactions with enhanced capacitive contribution and high reaction reversibility by a binding-energy-driven atomic scissors method would break new ground on designing a high-rate and high-capacity sodium-ion batteries.

Ultrafast Synthesis of Layered Transition-Metal Oxide Cathodes from Metal-Organic Frameworks for High-Capacity Sodium-Ion Batteries.

Layered transition-metal oxides are promising candidate cathode materials for sodium-ion batteries due to their abundant raw materials and high theoretical capacity. Nevertheless, a long-time high-temperature heat treatment is required in traditional preparation methods, leading to low synthesis efficiency and waste of energy. Herein, an ultrafast preparation method of layered transition-metal oxides was proposed through minute calcination of metal-organic frameworks (MOFs). The homogeneous distribution of different atoms in MOFs allows fast phase transition during the calcination process. P'2-phase layered sodium manganese oxide was successfully obtained and demonstrated excellent electrochemical performance, with a high reversible capacity of 212 mA h g-1 and a cycling performance of 84% capacity retention after 100 cycles. Furthermore, this method can be expanded to a wide variety of MOF precursors and oxide electrode materials for different types of batteries. Our findings provide an efficient and cost-effective synthesis method for high-performance layered transition-metal oxide cathodes.

Confined Iterative Self-Assembly of Ultrathick Freestanding Electrodes with Vertically Aligned Channels for High Areal Capacity Sodium-Ion Batteries

Electrodes with a high areal capacity are critical for developing high-energy-density sodium-ion batteries (SIBs). The free-standing thick electrode is a promising candidate among the state-of-art electrodes, since it has the advantages of high areal mass, binder-free, current-collector-free, and no carbon additive; thus, the whole mass of the electrode is an active material that can contribute to capacity. However, enhancing areal density by introducing thick electrodes impinges on the transport of charge carriers including ions and electrons. Here we designed and synthesized an ultrathick (1500 μm) free-standing foam, which is a carbon framework with 1T-MoS2 nanosheets embedded in the vertically aligned channel wall. To tune the areal mass and morphology of the as-obtained foam, a confined iterative self-assembly strategy was proposed. The Na+ storage behavior was studied by using the as-obtained foam as a free-standing electrode against Na metal. Consequently, it displays good cycle stability even with a high areal mass of 20.74 mg cm–2 and delivers an astonishing reversible areal capacity of 19.75 mAh cm–2 at 0.01 A g–1, which greatly exceeds that of most sodium storage materials. The proposed confined iterative self-assembly strategy for fabricating thick electrodes opens new avenues for high areal capacity batteries.