Figure - available from: Advanced Materials
This content is subject to copyright. Terms and conditions apply.
In/ex situ characterization. a,b) In situ Raman spectra of HCM‐1300‐ZBE. c) In situ XRD of HCM‐1300‐ZBE during the first discharge−charge process at the 0.10 A g–1 at 293 K. d) Ex situ ²³Na MAS NMR of HCM‐1300 and HCM‐1300‐ZBE after discharging to 0.01 V. e) Na 1s of HCM‐1300‐ZBE at different voltages. f–h) O 1s of the HCM‐1300‐ZBE electrode at the stage of pristine and discharge to 0.90 V, 0.50 V states. i) Illustration of the sodium storage mechanism.
Source publication
Efficient electrode materials, that combine high power and high energy, are the crucial requisites of sodium-ion batteries (SIBs) which have unwrapped new possibilities in the areas of grid-scale energy storage. Hard carbons (HCs) are considered as the leading candidate anode materials for SIBs, however, the primary challenge of slow charge transfe...
Similar publications
The practical application of hard carbon in sodium‐ion batteries is limited by insufficient reversible capacity and low initial Coulombic efficiency (ICE), which are caused by the lack of active sites and unstable electrode/electrolyte interface. Herein, a biomass‐derived hard carbon material based on tea stems is proposed, which exhibits an ultrah...
The pore structure of hard carbon has an important influence on its sodium storage performance. In this study, Pitch‐derived hard carbons with different pore structures have been prepared via the combination of physical activation and vapor carbon coating. It reveals that the open pores favour the slope capacity while the closed pores can promote t...
Sodium batteries, encompassing sodium‐ion batteries (SIBs) and sodium metal batteries (SMBs), have emerged as a significant trend in the advancement of secondary batteries owing to the natural abundance and economical characteristics of sodium. Despite significant strides in enhancing the electrochemical performance of sodium batteries, understandi...
Single atomic metal (SAM) doping is reported as an effective strategy to promote the electrochemical property of carbon‐based anode materials for high‐power sodium‐ion batteries (SIBs). However, the effects of SAM with different configurations on solid electrolyte interphase (SEI) and energy storage mechanism of Na⁺ are not revealed. Herein, Cr sin...
Citations
... After decades of research, a consensus has been reached that closed pores having pore mouths being inaccessible to N 2 molecular probes are a prerequisite for increasing the ICE and the emergence of LPPs [8][9][10][11][12][13][14] . Zheng et al. demonstrated the critical role of closed pores below 1 nm in reducing the SEI thickness and increasing the reversible capacity 15 . ...
Closed pores are widely accepted as the critical structure for hard carbon negative electrodes in sodium-ion batteries. However, the lack of a clear definition and design principle of closed pores leads to the undesirable electrochemical performance of hard carbon negative electrodes. Herein, we reveal how the evolution of pore mouth sizes determines the solvation structure and thereby redefine the closed pores. The precise and uniform control of the pore mouth sizes is achieved by using carbon molecular sieves as a model material. We show when the pore mouth is inaccessible to N2 but accessible to CO2 molecular probes, only a portion of solvent shells is removed before entering the pores and contact ion pairs dominate inside pores. When the pore mouth is inaccessible to CO2 molecular probes, namely smaller than 0.35 nm, solvent shells are mostly sieved and dominated anion aggregates produce a thin and inorganic NaF-rich solid electrolyte interphase inside pores. Closed pores are accordingly redefined, and initial coulombic efficiency, cycling and low-temperature performance are largely improved. Furthermore, we show that intrinsic defects inside the redefined closed pores are effectively shielded from the interfacial passivation and contribute to the increased low-potential plateau capacity.
... Another approach to improving rate performance is optimizing the pore structure of hard carbon. Techniques such as catalyst addition [26], template-assisted methods [9,22,23], and chemical etching [20,21] can effectively regulate pore structure, offering comprehensive improvement in performance. However, these methods are often complex, timeconsuming, and require acid washing to remove templates or etching agents, leading to additional energy consumption and environmental pollution. ...
Hard carbon is a promising anode material for sodium-ion batteries (SIBs) due to its low cost, environmental friendliness, and potential for commercialization. However, its relatively low rate performance limits its application in fast-response energy storage systems, such as smart grids. In this study, bamboo-derived hard carbon was synthesized using a two-step process: low-temperature oxygen activation followed by high-temperature carbonization. Oxygen activation plays a key role in developing a mesoporous structure, enhancing the rate performance and capacity retention of the material. Additionally, oxygen-containing functional groups increase the interlayer spacing, improving intercalation capacity. The optimized anode, OEHC, achieved a reversible capacity of 316.41 mAh g⁻¹ at 0.1C, with high capacities of 210.98 mAh g⁻¹ at 2C and 102.25 mAh g⁻¹ at 5C. The mesoporous structure and oxygen-containing groups promote faster Na⁺ diffusion, reduce polarization effects, and improve kinetics at high rates, resulting in enhanced capacity retention. The preparation method is simple, efficient, and environmentally friendly, contributing to reducing the environmental impact of production.
... As the temperature further increases, there is a slight catalysis of partial graphitization of the HC. Concurrently, a bulk-etching phenomenon is observed within the graphitic layers by the reaction ZnO + C = Zn + CO↑, mostly producing metallic Zn, which can evaporate above 900°C [31]. Notably, this process results in the formation of plenty of small voids within HC, further impeding directed graphitization and generation of a large number of nanopores. ...
Hard carbons are promising anode materials for sodium‐ion batteries (SIBs), but they face challenges in balancing rate capability, specific capacity, and initial Coulombic efficiency (ICE). Direct pyrolysis of the precursor often fails to create a suitable structure for sodium‐ion storage. Molecular‐level control of graphitization with open channels for Na⁺ ions is crucial for high‐performance hard carbon, whereas closed pores play a key role in improving the low‐voltage (< 0.1 V) plateau capacity of hard carbon anodes for SIBs. However, creation of these closed pores presents significant challenges. This work proposes a zinc gluconate‐assisted catalytic carbonization strategy to regulate graphitization and create numerous nanopores simultaneously. As the temperature increases, trace amounts of zinc remain as single atoms in the hard carbon, featuring a uniform coordination structure. This mitigates the risk of electrochemically irreversible sites and enhances sodium‐ion transport rates. The resulting hard carbon shows an excellent reversible capacity of 348.5 mAh g⁻¹ at 30 mA g⁻¹ and a high ICE of 92.84%. Furthermore, a sodium storage mechanism involving “adsorption–intercalation–pore filling” is elucidated, providing insights into the pore structure and dynamic pore‐filling process.
... Modulation approaches have been developed for the design of HCs including pretreatment before the carbonization process, heteroelement doping, templating methods, and chemical etching/ deposition for pore regulation (28)(29)(30)(31)(32). As a typical example, Yang's group proposed sieving carbon with highly tunable nanopores with tightened pore entrances via chemical vapor deposition of methane on commercial porous carbon (23). ...
The practical application of Li metal anodes has been hindered by severely irreversible side reactions for low Coulombic efficiency, uncontrollable growth of Li dendrites, and large volume change. Herein, we report subnanopore-rich carbon spheres encapsulated with Sn single atoms (Sn/CS@SC) as a Li host to address these challenges. Owing to the high Li affinity of Sn single atoms, Sn/CS@SC can promote storage of quasi-metallic Li within the inner void space other than direct plating of metallic Li on the outer surface. Moreover, the subnanopores with a strong spatial confinement effect can prevent the penetration of ester electrolyte for reduced side reactions. As expected, the Sn/CS@SC host demonstrates a high Coulombic efficiency of 99.8% over 600 cycles. Moreover, a full cell using a prelithiated Sn/CS@SC anode and LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode shows high capacity retention (~80%) over 500 cycles at high current density.
... Different from graphite, hard carbon (HCs) materials with high specic capacities (z300 mA h g −1 ) and excellent cost-effectiveness are considered to be the most feasible anode materials of SIBs for further commercialization. 7 As typical eco-friendly resources, biomass has become a global hot topic of sustainable chemistry due to its great potential for practical application. In recent years, researchers are paying more attention to synthesis of hard carbon via abundant biomass-based materials instead of expensive inorganic materials, such as peat moss, 8 grapefruit peel, 9 nutshell, 10 reed straw, 11 cork, 12 and palm fruit calyx. ...
Optimized chemical pretreatment method facilitates the synthesis of biomass-based hard carbon with rich porosity at lower carbonization temps (900–1300 °C), yielding cost-effective and high-performance anode materials. The cypress-derived hard carbon (WC-1100) with hierarchical pores achieves a peak sodium ion storage of 307 mA h g⁻¹ at 0.1 A g⁻¹ with an impressive ICE of 82.5%.
... This may be due to zinc playing a catalytic role in graphitization. 26 An appropriate increase in graphitization degree is conducive to the interlayer intercalation of sodium ions. The FWHMs of BHC, BHC-Zn-81, BHC-Zn-41, and BHC-Zn-11 are 7.167, 5.045, 3.728, and 2.430, respectively. ...
Hard carbon is considered the most commercially viable anode material for sodium ion batteries due to its excellent sodium storage properties. However, the production cost of hard carbon is high, so optimizing the electrochemical performance of coal-derived hard carbon is adopted. However, due to the dense structure of coal, it is difficult to prepare closed pores inside the coal-derived hard carbon, which is not conducive to increasing capacity. Therefore, we propose Zn2(OH)2CO3 assisted ball milling pretreatment followed by carbonization to generate closed pores in coal-derived hard carbon. The reason for the formation of closed pores is that the uniform pores on the coal surface generated by the wear and etching of Zn2(OH)2CO3 are repaired at high temperatures. Via mechanism characterization, we verified that the plateau capacity is related to the filling of sodium ions in closed pores. Therefore, the as-prepared coal-derived hard carbon delivers a high capacity of 325.3 mA h g⁻¹ (plateau capacity accounting for 45.1%) at a current density of 0.03 A g⁻¹ with a capacity retention rate of 83.5% over 500 cycles. This work has demonstrated that reasonable pore design is an effective strategy to improve the electrochemical sodium storage performance of coal-derived hard carbon, providing an effective approach for the high value-added utilization of coal.
... As shown in Fig. S17, Bi/CNRs-15 displays a typical mesoporous structure with a specific surface area of 48.1 m 2 g −1 . The high porosity increases the contact areas between the electrolyte and electrode, and decreases the Na + diffusion distance, facilitating the rate performance of Bi/CNRs-15 [56]. ...
Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at − 20 °C or lower. However, the key capability of ultrafast charging at ultralow temperature for SIBs is rarely reported. Herein, a hybrid of Bi nanoparticles embedded in carbon nanorods is demonstrated as an ideal material to address this issue, which is synthesized via a high temperature shock method. Such a hybrid shows an unprecedented rate performance (237.9 mAh g⁻¹ at 2 A g⁻¹) at − 60 °C, outperforming all reported SIB anode materials. Coupled with a Na3V2(PO4)3 cathode, the energy density of the full cell can reach to 181.9 Wh kg⁻¹ at − 40 °C. Based on this work, a novel strategy of high-rate activation is proposed to enhance performances of Bi-based materials in cryogenic conditions by creating new active sites for interfacial reaction under large current.
Supplementary Information
The online version contains supplementary material available at 10.1007/s40820-024-01560-9.
... Benefiting from the ideal structure, CTSFS 1300 has excellent LT performance (Figure 1f). More importantly, Yin et al. found that the carbon p-band center upholds a linear relationship with both the Na + adsorption energy (Ea) and diffusion energy barrier (Eb), which can be readily manipulated by adjusting the physical parameters of the hard carbons Nanomaterials 2024, 14, 1604 5 of 32 (HCs) [42]. They synthesized HC microspheres with a well-regulated microstructure via the ZnO-assisted bulk etching method ( Figure 1g). ...
... The application of hard carbon in SIBs at LTs is still worth exploring. the hard carbons (HCs) [42]. They synthesized HC microspheres with a well-regulated microstructure via the ZnO-assisted bulk etching method ( Figure 1g). ...
Sodium-ion batteries (SIBs) have garnered significant interest due to their potential as viable alternatives to conventional lithium-ion batteries (LIBs), particularly in environments where low-temperature (LT) performance is crucial. This paper provides a comprehensive review of current research on LT SIBs, focusing on electrode materials, electrolytes, and operational challenges specific to sub-zero conditions. Recent advancements in electrode materials, such as carbon-based materials and titanium-based materials, are discussed for their ability to enhance ion diffusion kinetics and overall battery performance at colder temperatures. The critical role of electrolyte formulation in maintaining battery efficiency and stability under extreme cold is highlighted, alongside strategies to mitigate capacity loss and cycle degradation. Future research directions underscore the need for further improvements in energy density and durability and scalable manufacturing processes to facilitate commercial adoption. Overall, LT SIBs represent a promising frontier in energy storage technology, with ongoing efforts aimed at overcoming technical barriers to enable widespread deployment in cold-climate applications and beyond.
... 48−50 At the final stages, the disappearance of G peak originates from lithium-ion interactions between the adjacent metallic-like features of the carbon layers and the resonant phonon scattering process. 10 Meanwhile, the intensity of the D band is weakened and until it vanishes during the discharge process. This is attributed to the centers of diacetylenic triangular−like pores and sp 2 carbon breathing motion in the rings at edge planes occupied by the introduction of Li + . ...
Graphdiyne (GDY) is a promising anode for rechargeable batteries with high capacity, outstanding cyclic stability, and low diffusion energy. The unique structure of GDY endows distinctive mechanisms for metal-ion storage, and it is of great significance to further visualize the complex reaction kinetics of the redox process. Here, we systematically tracked the reaction kinetics and provided mechanistic insights into the lithium ions in the GDY to reveal the feature of the cation-π effect. It has been demonstrated that, unlike only one π bond in sp²-C, π electrons provided by one of the two alkynyl π bonds in sp-C can achieve proper interaction and speedy capture of lithium ions; thus, reversible Li–C coupling can be formed between electron-rich sp-C and lithium ions. In addition to interlayer intercalation in sp²-C regions, nanopores filling triangular-like cavities composed of highly conjugated sp-C contribute to the major capacity in flat voltage plateau regions. Therefore, a capture/pores filling-intercalation hybrid mechanism can be found in GDY. The coexistence of sp and sp² carbon enables GDY electrodes with rapid Li⁺ diffusion, high capacity of over 1435 mAh g–1, extraordinary rate capability, and cyclic stability for more than 10000 cycles at 10A g–1. These results provide guidance for developing advanced carbon electrodes with optimized reaction kinetics for rechargeable batteries.
... The material exhibited a high reversible capacity of 478 mAh g −1 and a high ICE of 88% in the first cycle at 25 mA g −1 . Yin et al [118] used phenolic resin as the precursor, introduced nanometer ZnO in the precursor synthesis stage and prepared porous hard carbon by one-step carbonization. At high temperatures, ZnO reacts with carbon to form gaseous Zn and carbon monoxide ( figure 7(a)). ...
With the continuous exploration of researchers in the field of sodium-ion batteries, the performance of these batteries has been greatly improved, and they have a wide range of application prospects in large-scale energy storage, traffic power and other fields. Hard carbon is the most important anode material for sodium-ion batteries. Although it has the advantages of low cost, stable structure and performance, it still has the problems of low initial Coulombic efficiency (ICE) and poor rate performance in application. In order to solve the problem of low ICE of hard carbon anode in sodium-ion batteries, in recent years the literature about hard carbon anode in sodium-ion batteries has been comprehensively reviewed. Based on the microstructure of hard carbon material, the causes of low ICE of hard carbon are analyzed. At the same time, from the point of view of material structure design and regulation, the current optimization strategies of hard carbon anode ICE are summarized, including the following aspects: optimization and improvement of the carbonization process, precursor screening and design, surface coating strategy, micro-pore structure control, catalytic carbonization strategy. We hope that this review will provide reference for further optimization of hard carbon properties and its large-scale application in sodium-ion batteries.
