Hard Carbon Materials Research Articles

Study on the lignin-derived sp2–sp3 hybrid hard carbon materials and the feasibility for industrial production

Hard carbon has been widely used in anode of lithium/sodium ion battery, electrode of supercapacitor, and carbon molecular sieve for CO2 capture and hydrogen storage. In this study the lignin derived hard carbon products are investigated, and the conclusions are abstracted as follows. (1) The lignin derived hard carbon products consist of microcrystal units of sp2 graphene fragments, jointed by sp3 carbon atoms and forming sp2–sp3 hybrid hard carbon family. (2) From the lignin precursors to the sp2–sp3 hybrid hard carbon products, most carbon atoms retain their original electron configurations (sp2 or sp3) and keep their composition in lignin. (3) The architectures of lignin-derived hard carbon materials are closely dependent on the forms of their lignin precursors, and could be preformed by different pretreatment techniques. (4) The carbonization of lignin precursors follows the mechanism “carbonization in situ and recombination nearby”. (5) Due to the high carbon ratio and abundant active functional groups in lignin, new activation techniques could be developed for control of pore size and pore volume. In general lignin is an excellent raw material for sp2–sp3 hybrid hard carbon products, a green and sustainable alternative resource for phenolic resin, and industrial production for lignin derived hard carbon products would be feasible.

Carbons Derived from Regenerated Spherical Cellulose as Anodes for Li-Ion Batteries at Elevated Temperatures.

Biomass-based materials have emerged as a promising alternative to the conventional graphite anode in Li-ion batteries due to their renewability, low cost, and environmental friendliness. Therefore, a facile synthesis method for porous hard carbons based on cellulose acetate microspheres and bead cellulose is used, and their application as anode materials in Li-ion batteries is discussed. The resulting porous carbons exhibit promising electrochemical characteristics, including a reversible capacity of about 300 mAh g-1 at 0.1 C (37 mA g-1) after 50 cycles, and stable capacities up to 210 mAh g-1 over 1000 cycles at 1 C (372 mA g-1) in half-cells for cellulose acetate microspheres carbonised at 1200 °C. Moreover, at 60 °C cellulose-derived carbons show higher specific capacities than graphite (300 mAh g-1 vs 240 mAh g-1 at 1 C after 500 cycles), indicating their potential for use in high-temperature applications. The different charge storage mechanisms of the prepared hard carbon materials and graphite are observed. While capacity of graphite is mainly controlled by the Faradaic redox process, the cellulose-derived carbons combine Faradaic intercalation and capacitive charge adsorption.

Design and microwave absorption characteristics of porous lamellar hard carbon materials

Porous lamellar hard carbon structures were synthesized using the direct hard template strategy with phenolic resin as the C source and ZnO as the template. The porosity of the hard carbon materials is adeptly fine-tuned by regulating the ZnO nanoparticle content. Notably, the introduction of porosity to lamellar hard carbon materials is shown to have a significant impact on their microwave absorption properties. A porous lamellar hard carbon material with impressive microwave absorption performance is synthesized, culminating in an optimal reflection loss of −45 dB and an effective absorption bandwidth of 4.08 GHz, even at a minimal absorber thickness of ∼2.0 mm, with a mere 16.7% filling rate. These findings illustrate how the control of porosity provides a new design avenue for tailoring the absorption characteristics for microwave absorbers. This design approach will support the further development of versatile microwave absorption solutions, helping to address the prevalence of electromagnetic pollution.

Optimizing Synthesis Temperature for Lignin-Derived Hard Carbon Anode for High Cycling Capacity in Sodium-Ion Batteries

This comprehensive study sheds light on the promising potential of lignin-derived carbonaceous materials as sustainable and cost-effective anode materials for sodium-ion batteries, contributing to the development of eco-friendly energy storage technologies. Lignin, a complex and abundant biopolymer, undergoes a facile pyrolysis process to produce carbonaceous materials. The unique microstructure of lignin-derived carbon, characterized by a relatively high surface area and interconnected porous network, facilitates efficient sodium ion diffusion and accommodates volume changes during cycling. The effects of pre-treatment methods, carbonization conditions, and structural modifications of lignin on the electrochemical performance are systematically investigated. Furthermore, the electrochemical mechanisms underlying the sodiation/desodiation processes in lignin-derived carbon (LDC) based anodes are elucidated through advanced characterization techniques, including in situ spectroscopy and microscopy. Among the different hard carbon materials, pre-pyrolyzed lignin-derived carbon LDC-300–1400 (300 shows which pre-treatment pyrolysis temperature was used and 1400 is the post-pyrolysis temperature in °C) shows the most favourable outcomes, demonstrating a reversible capacity of 359 mAh g−1, 1st cycle coulombic efficiency of 81%, and good rate capabilities. Hydrothermally pre-treated LDCs show a slightly lower specific capacity value reaching up to 337 mAh g−1.

Tea‐Derived Sustainable Materials

AbstractThe 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 ultrahigh ICE of 90.8%. This remarkable ICE is attributed to the presence of an inorganic‐rich, thin, and robust solid electrolyte interface (SEI) layer. Furthermore, the material demonstrates excellent cycling stability, showing a capacity retention of 99.5% after 500 cycles at 280 mA g−1. Additionally, when it works as the anode material in a sodium‐ion full cell without presodiation, it reaches a high energy density of 212 Wh kg−1 and a superior stability, e.g., retaining 93.1 mAh g−1 after 1000 cycles at 1 A g−1 with a capacity retention of 91.3%. The sodium storage capacity of this material is primarily attributed to a combined adsorption‐intercalation/filling effect as confirmed by in situ XRD and ex situ Raman analyses. These findings make this biomass‐derived hard carbon material a promising candidate for commercial application of sodium‐ion batteries, achieving high performance at low cost.

Preparation of green high-performance biomass-derived hard carbon materials from bamboo powder waste.

Efficient energy storage systems are crucial for the optimal utilization of renewable energy. Sodium-ion batteries (SIBs) are considered potential substitutes for next-generation low-cost energy storage systems due to the low cost and abundance of sodium resources. However, the industrialization of SIBs faces a great challenge in terms of the anode. Hard carbon could be a promising anode material due to its high capacity and low cost which originates from biomass. This study used pre-treatment and template carbonization methods to extract a hard carbon material from a large amount of discarded biomass in bamboo powder waste. This material has a good initial Coulombic efficiency of 78.6 % and good cycling stability when applied to sodium ion batteries.Typically, the optimal hard carbon material is used as the anode to prepare sodium ion battery prototypes to demonstrate their potential applications. The anode exhibited excellent sodium storage performance with a reversible capacity of 303 mAh ⋅ g-1 at 1 C rate and good cycling performance, retaining 92.0 % of its capacity after 100 cycles. These results demonstrate that BPPHC is a promising candidate for anode material in sodium-ion batteries. This work suggests that bamboo powder could be a low-cost anode material for SIBs.

P-doped hard carbon material for anode of sodium ion battery was prepared by using polyphosphoric acid modified petroleum asphalt as precursor

The practical value of hard carbon anode in sodium ion batteries has garnered significant attention. Asphalt-derived hard carbon offers lower cost and scale advantages compared to expensive resin and bio-based hard carbon materials. However, the synthesis of asphalt-derived hard carbon with significantly enhanced reversible capacity remains challenging. This study focuses on synthesizing P-doped hard carbon material using polyphosphoric acid-modified petroleum asphalt as a precursor and the pre-oxidation method. Doping P elements in hard carbon induces deformation of the molecular layer structure within the pseudo-graphite domains, expanding graphite layer spacing and increasing the number of internal closed micropores, thereby enhancing the sodium storage capacity of the matrix. The reversible capacity of P-doped hard carbon (PHC-1300) increased from 240.3 mA h g−1 to 359.9 mA h g−1 during the initial charge-discharge cycle at a rate of 0.05 C compared to undoped hard carbon (HC-1300). Moreover, phosphate exhibits higher reduction ability than adjacent carbon atoms, generating electron holes that partially compensate for limited electron conduction capability in hard carbon material. The electronic conductivity of the material increases from 26.1114 S cm−1 to 36.6418 S cm−1, demonstrating a significant enhancement compared to high graphitized soft carbon (SC-1300).Therefore, the practical significance of employing this straightforward precursor modification method to prepare P-doped hard carbon warrants attention.

A molecular-scale regulation strategy for designing asphalt-based hard carbon for superior sodium storage

The asphalt-based hard carbon material prepared by the novel gradient pre-oxidation process exhibits a more disordered microstructure. Additionally, it demonstrates excellent cycling performance, laying an excellent foundation for future research.

Development and Prospect of Electrode Materials for Sodium Ion Batteries

Sodium-ion batteries, with the advantages of low cost and abundant resources, have become an effective complement to lithium-ion batteries in application scenarios such as large-scale energy storage systems and short-distance electric vehicles. Nevertheless, sodium-ion batteries generally lag behind lithium-ion batteries in energy density. The aim of this paper is to provide an overview of current research results on anode and cathode materials and to provide insights into the challenges faced by various materials, such as the deficiencies of hard carbon materials for the anode in terms of sodium storage capacity and stability at the solid electrolyte interface (SEI), and the poor air stability and susceptibility to phase transitions of layered oxides for the cathode. Further, the report proposes several innovative solutions with the goal of developing better sodium ion electrode materials. These strategies include, but are not limited to: improving the microstructure of hard carbon through nano-engineering techniques to enhance its sodium storage capacity; and employing surface coating or doping methods to improve the air stability of cathode materials. Through these research endeavors, this paper expect to provide a solid scientific foundation and new perspectives for the advancement and application expansion of sodium-ion battery technology.

Structural design of biomass-derived hard carbon anode materials for superior sodium storage via increasing crystalline cellulose and closing the open pores

Through the two-step acid treatment and two-stage heat treatment method proposed in this study, the properties of almond shells were efficiently modulated and transformed into hard carbon materials rich in closed pores and oxygen-containing groups.

Elucidating the Lithium-Ion Storage Mechanism in Insertion-Available Hard Carbon with Abundant Closed Porosity: Toward a Practical Material for Batteries

Traditionally, standard lithium-ion batteries (LIBs) are composed of a positive electrode made of metal oxides and a negative electrode made of highly crystallized graphite materials. Graphite materials, with a theoretical capacity of 372 mAh g-1, are chosen as the negative electrode because lithium-ion storage in graphite materials involves lithium-ion intercalation/de-intercalation between graphitic interlayers, a characteristic of faradaic reactions. During galvanostatic charge/discharge (GCD), long plateau regions at low voltages (e.g., 0-0.1 V (vs. Li+/Li)) resulting from multi-staged ion intercalation/de-intercalation are achieved. The low voltage of this intercalation/de-intercalation reaction contributes to enhancing the nominal voltage of LIBs, leading to a higher energy density of the battery.On the other hand, sodium-ion batteries (SIBs) have been extensively researched over the past 10 years as alternative to LIBs to compensate for the gradual scarcity of lithium metal resources. Hard carbon (HC) materials, also known as amorphous non-graphitizable carbons, were introduced to be the negative electrode material for SIBs, since most HCs exhibit very similar electrochemical responses in sodium-ion storage as lithium-ion storage in graphite materials.However, when examining the application of HC materials in lithium-ion storage, it becomes apparent that the development has been significantly limited over the past 20 years. Recent research primarily focuses on biomass-derived HCs and heteroatom-doping on these carbons. This type of HC is abundant in heteroatoms (e.g., N, P, and S) inherited from the intrinsic properties of biomass precursors. While high capacities and excellent rate capabilities are claimed for these biomass-derived HCs, the electrochemical responses of lithium-ion storage in these HCs often exhibit capacitive reactions with a completely sloping region on their GCD curves. Consequently, the miscalculation of capacities can be induced by assessing reversible capacities beyond excessively high voltages (> 1.5 V), even reaching 3 V. The appropriate working voltage window for HCs should be lower than 1.5 V to match with the positive electrodes. Thus, if reevaluating these HCs in a normal voltage window, the obtained reversible capacities are relatively small, due to the deficiency of faradaic reactions signified by the plateau region at low voltages on GCD curves. Additionally, very low initial coulombic efficiencies are often obtained for these highly defected and heteroatom-doped HCs, attributed to the vigorous consumption of electrolyte during the SEI layer formation on their defective sites. As a result, in this work, we introduce a straightforward method to fabricate hard carbon microbeads with tunable microporous structures by carbonizing cross-linked phenolic-formaldehyde (PF) resin spheres, produced through microwave-assisted suspension polymerization. The ultimate goal is to transform HC into a practical battery material for the negative electrode in LIBs, which must possess several abilities similar to graphite (i.e., reversible faradaic reactions with an obvious plateau region at low voltages on GCD curves, low surface area to suppress SEI formation, and good cycling stability). Additionally, the lithium-ion storage mechanism in HCs with varying open/closed porosity is carefully elucidated. By probing the porosity of HC with multiple gas (N2, O2, and CO2) adsorptions, a solid correlation between porous properties and electrochemical responses has been successfully established. As displayed in Figure 1, the results indicate that carbon porosity can change with carbonization temperature. With increasing temperatures, open pores are initially transformed into closed pores, and ultimately, non-porous properties are detected. The electrochemical behaviors in these HCs with distinct porosity differ significantly as demonstrated by GCD curves in Figure 2.It has been found that ultra-micro closed pores (<0.7 nm) are capable of providing confined spaces for lithium ions to be inserted/extracted, characterized as faradaic reactions. Therefore, a plateau region at low voltages can be acquired, leading to additional reversible capacities. Unlike some reported methods, such as holding at a constant voltage, charging/discharging at a very small current density, or overcharging to negative voltage regions, these faradaic reactions are easily unlocked at a current density of 50 mA g-1 in a safe voltage window of 0-0.12 V. As a result, the optimized HC delivers a total reversible capacity of 550 mAh g-1 at 50 mA g-1 in the voltage range of 0-1.5 V. The excellent rate capability and cycling stability of optimized HC are also confirmed. Furthermore, by the post-treatment with hydrogen-assisted reduction, the performance is further enhanced, achieving a reversible capacity of 574 mAh g-1 and an initial coulombic efficiency of 75%. These breakthrough outcomes provide valuable insights for the rational design of hard carbon materials. The optimized hard carbon could be a promising candidate for replacing traditional graphite materials in next-generation LIBs. Figure 1

Developing Tailor-Made Core-Shell Hard Carbon Materials As Anode Materials in Sodium Ion Batteries

The current strong interest in electromotive mobility and the need to transition to an energy grid with sustainable storage devices has led to a renewed interest in sodium ion batteries (SIBs). Hard carbons (HCs) are promising candidates for high-capacity negative electrode materials in SIBs. Their high capacities, however, are often accompanied with high irreversible capacity losses during the initial cycles.[1]Generally, large losses can be connected to irreversible reactions, e.g., the formation of the solid electrolyte interphase (SEI), during the initial sodiation of the HC-material. However, high irreversible capacity values are often in contradiction to the experimentally determined low surface area of the sample material.[1] A better understanding of the structure-property relationship should enable quantification and understanding of the potential of hard carbon materials for SIBs. Hence, the aim is to use analytical techniques to establish a correlation between the structure and the electrochemical characteristics of HC-materials. This has previously been difficult, in part because the sodium storage mechanism is not stoichiometric and due to the disordered structure of HCs.In order to tackle the aforementioned challenges, our approach is to explore whether a core-shell structure can separate sodium storage and solid electrolyte interphase formation. Thus, storage capacity and irreversible losses could be investigated and finally optimized separately. The synthesis of a selection of porous carbon structures serving as the core material, will be attempted. Simultaneously, sodium-conducting shell structures will be developed to allow for separation of sodium ions and electrolyte molecules. Subsequently, the combination of core and shell materials will be undertaken. These anodes should enable high capacities accompanied with low irreversible losses due to optimized SEI-formation.Literature:[1] Matsukawa, Y.; Linsenmann, F.; Plass, M. A.; Hasegawa, G.; Hayashi, K.; Fellinger, T.-P. Beilstein J. Nanotechnol. 2020, 11, 1217–1229.

Hard carbon-based electrode boosts the performance of a solid-state symmetric supercapacitor

Hard carbon materials have gained extensive utilization in energy storage systems because of their stable chemical properties, unique lamellar arrangement, and significant interlayer spacing. In this study, we present a novel porous carbon electrode based on hard carbon to enhance the performance of a solid-state symmetric supercapacitor. This electrode was fabricated through an efficient and straightforward synthetic approach using natural asphalt as the precursor. The resulting carbon electrode exhibits remarkable features including a large surface area (2334.48 m2 g−1), a well-distributed pore size (mesopore ratio of 16.04 %), an appropriate oxygen content (18.11 %), and a lamellar structure. As a result, the as-prepared carbon electrode demonstrates a high specific capacitance of 325.82 F g−1 at 0.5 A g−1, along with excellent rate capability, with coulombic efficiency ranging from 99.89 % at 0.5 A g−1 to 98.92 % at 10 A g−1. Moreover, the assembled symmetrical all-solid-state supercapacitor utilizing this electrode achieves an energy density of 18.91 Wh Kg−1, an equivalent series resistance of 0.820 Ω, a relaxation time of 9.0 s, and self-discharge performance lasting up to 72 h. Notably, owing to its large layer spacing (0.391 nm), the electric double layer capacitor contributes as much as 94 %, indicating favorable electrical double layer characteristics. Our work not only showcases a high-performance electrode material but also contributes to the expanded application of hard carbon.

Pre-Oxidation Strategy Transforming Waste Foam to Hard Carbon Anodes for Boosting Sodium Storage Performance.

Large reserves, high capacity, and low cost are the core competitiveness of disordered carbon materials as excellent anode materials for sodium-ion batteries (SIBs). And the existence and improper treatment of a large number of organic solid wastes will aggravate the burden on the environment, therefore, it is significant to transform wastes into carbon-based materials for sustainable energy utilization. Herein, a kind of hard carbon materials are reported with waste biomass-foam as the precursor, which can improve the sodium storage performance through pre-oxidation strategy. The introduction of oxygen-containing groups can promote structural cross-linking, and inhibit the melting and rearrangement of carbon structure during high-temperature carbonization that produces a disordered structure with a suitable degree of graphitization. Moreover, the micropore structure are also regulated during the high-temperature carbonization process, which is conducive to the storage of sodium ions in the low-voltage plateau region. The optimized sample as an electrode material exhibits excellent reversible specific capacity (308.0mAhg-1) and initial Coulombic efficiency (ICE, 90.1%). In addition, a full cell with the waste foam-derived hard carbon anode and a Na3V2(PO4)3 cathode is constructed with high ICE and energy density. This work provides an effective strategy to conversion the waste to high-value hard carbon anode for sodium-ion batteries.

Unveiling the impact of ultramicropores in carbonaceous electrode materials to boost surface-driven capacitive potassium ion storage in hybrid supercapacitors

Porous structure engineering has proven highly effective in enhancing the electrochemical performance of hard carbon anode materials in potassium ion hybrid supercapacitors (PIHCs). However, the relationship between the porous structure and the K+ storage behavior in these materials remains unclear, and requires further investigation. In this study, we prepare three types of carbon materials, namely micropore-dominated, ultramicropore/mesopore-mixed, and mesopore-dominated carbons, using ZnCl2 as salt template. We explore the impact of the (ultra)micropores and mesopores on the storage behavior of K+ ions in hard carbon anodes, and find that the ultramicropore volume plays a major role in enhancing the capacitive charge storage. A positive linear correlation between ultramicropore volume and capacitive K+ storage is identified for the first time. In addition, the mesopores enhance the K+ storage capacity by facilitating the transport of K+ ions and shortening their diffusion path. As a result, ultramicropore-enriched mesoporous carbon shows promise as anode material for PIHCs, achieving an energy density of 128 Wh kg−1, a power density of 9,536 W kg−1, and an outstanding capacity retention of 83.2% after 10,000 cycles at 1.0 A g−1. This study advances the fundamental understanding of porous structure design to enhance capacitive K+ storage in hard carbon materials.

Pretreatment Process Before Heat Pyrolysis of Plant‐based Precursors Paving Way for Fabricating High‐Performance Hard Carbon for Sodium‐Ion Batteries

AbstractThe increasing demand for sodium‐ion batteries has risen due to sodium resources that are inexpensive and abundant compared with its counterpart of lithium‐ion batteries. Development of anode materials with high performance is central issue for sodium‐ion batteries. Plant‐based hard carbon material is a promising anode material for sodium ion batteries due to its green preparation process, favorable ions transport channel, and special porous structure. Previous studies have not systematically correlated the material's inherent structure limitation with its electrochemical properties, resulting in a complex classification and a lack selection of pretreatment methods. In this review, the intrinsic limitations in the structure of plant‐based precursors are divided into four parts, including impure components, single chemical structure, uncontrollable crystalline texture, and irregular porous structure. The previous pretreatment methods are reclassified, including purification component aiming at plant‐based precursors, optimized structure, and precabornized process aiming at intermediate products. Furthermore, the pretreatment strategies are discussed according to the preferred structures of plant‐based hard carbon and the relationship between structure and performance is systematically expounded. This review provides deep understanding of the mechanism of pretreatment and a guide for selecting appropriate pretreatment strategies to optimize the structure of plant‐based hard carbon for sodium ion batteries.

S/N co-doped hierarchical porous carbon from lignite as high-performance anode for potassium-ion batteries

Because of their lower prices and exceptional physicochemical features, hard carbon materials have received a lot of interest in potassium ion batteries (PIBs). However, the slow K+ transport kinetics and significant volume expansion make the use of carbonaceous materials in PIBs anodes difficult. Here, S/N co-doped hierarchical porous carbon composites are designed as anodes for PIBs using lignite as raw material. The S/N co-doped carbon composites produced feature a hierarchical porous structure, which ensures structural resilience and speeds up ion/electronic transport. S/N co-doping in the carbon matrix not only creates an abundance of defects and active sites for K+, but it also increases the distance between layers, allowing for more accessible K+ intercalation/deintercalation. As a result, when used as anodes for PIBs, the obtained S/N co-doped hierarchical porous carbon composites have a large reversible capacity of 347.5 mAh g−1 after 100 cycles at 0.1 A g−1 with a capacity retention of up to 94 %, as well as excellent long cycle stability of 136 mAh g−1 after 1500 cycles at 1.0 A g−1.

The effect of thermal treatment temperature on the crystal structure and electrochemical performance of the coconut shell-based hard carbon

The demand for energy has been increased, and the supply of lithium-ion batteries (LIBs) can not meet the demand for energy storage. Sodium-ion batteries (SIBs) have become ideal alternative products because of their low cost and the similar charge and discharge mechanism with LIBs. Meanwhile, the hard carbon anode materials have made tremendous progress, and the hard carbon materials which have the advantages of rich resources, low cost, and high-safety have been widely studied. Herein, carbonized coconut shell was used as raw material for the preparation of hard carbon, and the relationship between thermal treatment temperature and the crystal structure and electrochemical performance was investigated. It is found that the hard carbon prepared at 1300 °C has the best specific capacity. At the current density of 100 mA/g, it can reach 224.36 mAh/g after 100 cycles. The hard carbon material prepared at 1200 °C has the best rate performance, which can reach 54.5 mAh/g at the current density of 2 A/g.

Macro-micro structure engineering of bio-spore-derived hard carbon as an efficient anode in sodium ion batteries

Elucidating the macro–micro structures of hard carbon is critical to address the issues of deficient Na+ storage capacity at the anode in Na+ ion batteries. Herein, hard carbon materials with various macro–micro structures were synthesized by pyrolyzing the spores of Calvatia Gigantea (SCG) as precursors treated by a coupling strategy with a dehydration process via concentrated H2SO4 treatment and the removal of inherent Si species by NaOH. Research results demonstrate that the process of concentrated H2SO4 pretreatment can induce the collapse of original hollow spheres of SCG to form specific hard carbon hollow hemispheres, while the NaOH leaching treatment can further modulate the microstructures of hard carbon. Attributed to the unique characteristics of specific hollow hemi-spherical morphology, ultra-low surface area, rich closed pore and appropriate layer spacing, the hard carbon not only exhibits outstanding specific capacity up to 500 mA h g−1 with a high initial Coulombic efficiency of 90.23 % for Na+ storage, but also presents excellent high-rate capability with 254.88 mA h g−1 at 5 A/g and cycling stability with a capacity retention rate of ≥80 % after 4102 cycles. The outstanding performance exceeds the vast majority of reported hard carbons for Na+ storage. Theoretical analysis further reveals that increasing closed pores constructed by distorted graphite-like layers together with proper lattice distance and curvature in hard carbon is essential to improve Na+ storage capacity. The coupling strategy of tuning the morphologies and microstructures of spore-derived hard carbon in the work provides new insights for developing advanced hard carbon with efficient Na+ storage performance.

Influence of Hard Carbon Materials Structure on the Performance of Sodium-Ion Batteries

Influence of Hard Carbon Materials Structure on the Performance of Sodium-Ion Batteries