High Proportion of Active Nitrogen-Doped Hard Carbon Based on Mannich Reaction as Anode Material for High-Performance Sodium-Ion Batteries

Biomass-based carbon material for next-generation sodium-ion batteries: insights and SWOT evaluation

In recent years, energy storage has significantly transitioned from lithium to sodium ion due to sodium's abundance and economical and optimal redox potential. Biomass-based carbon anode materials are extensively studied in sodium-ion batteries because of their economic advantages and eco-sustainable approach. Their distinctive microstructural characteristics resulting in higher specific capacitance. The present review explores hard carbon and a few emerging sustainable materials derived from various biomass sources. It also covers their production, focusing on micro-structures, morphological defects, and heteroatom doping-related aspects. However, the sodium storage mechanism within carbon anodes, particularly hard carbon, is a subject of debate due to its diverse microstructural states in contrast to the specific layered structure of graphite. It also integrates strengths, weaknesses, and opportunities with threat evaluation by highlighting detailed insights about recent developments in hard carbon. This review also highlights bibliographic analysis through network visualization map of international research collaboration in the field of biomass based anode material for sodium ion battery. It also offers a cohesive framework for advancing biomass-derived hard carbon and other carbon materials as an independent or complementary anode material for next-generation sodium-ion batteries.

Covalent Organic Nanosheets with a Tunable Electronic Structure to Achieve Unprecedented Stability and High-Performance in Sodium-Ion Batteries

This study develops a new type of fluorinated covalent organic nanosheets (CONs) as anode materials for sodium-ion batteries by incorporating an electron-withdrawing benzothiadiazole (BT) unit and F atom into the framework. These modifications lead to a reduced bandgap and electron density, generating strong permanent dipoles that increased Na+ accessible sites within the self-assembled solid-state structure. To elucidate the effect of these electronic changes, the Na+ storage performance of fluorinated D/A-CON-10-F is compared to that of nonfluorinated D/A-CON-10. The reduced electron density in D/A-CON-10-F weakens its interaction with Na+, yet enhances ion and charge carrier conductivities, leading to improved electrochemical performance. Notably, D/A-CON-10-F exhibits a reversible discharge capacity of ≈637 mA h g-1 at 100 mA g-1, maintaining structural stability over 5000 cycles with excellent rate capability. These results demonstrate that dipole engineering in CONs effectively enhances charge transport and long-term stability, offering a promising strategy for next-generation sodium-ion battery anodes.

B, N Co-Doped Hard Carbon Nano-Sponge Enhancing Half and Full Cell Performance in Na-Ion Batteries

Hard carbon is a promising anode material for next-generation sodium-ion batteries (NIBs) due to its high specific capacity, low working potential, and excellent structural stability. This research focuses on synthesizing boron- and nitrogen-co-doped hard carbon (BNHC), which shows enhanced sodium storage properties in half and full-cell configurations. The BNHC is prepared using a simple, scalable sol-gel method followed by pyrolysis for carbonization. Its 3D nano-sponge structure provides abundant active sites for sodium storage, while the low surface area and optimal interlayer distance minimize volume expansion during high-rate charge/discharge cycles, ensuring exceptional cycling stability. Compared to undoped hard carbon, BNHC demonstrates significantly improved sodium storage performance. The BNHC electrode achieves a reversible capacity of ≈310 mAh g⁻¹ with ultra-long cycling stability at high current rates and robust rate capability. It delivers ≈115 mAh g⁻¹ at an exceptionally high current density of 10 A g⁻¹. Further, BNHC//NaFePO4 full cell demonstrates excellent cycling stability with ≈206 mAh g⁻¹ at a 150 mA g⁻¹ current rate. This study paves the way to commercializing hard carbon as an anode material for sodium-ion batteries.

Multitrack Boosted Hard Carbon Anodes: Innovative Paths and Advanced Performances in Sodium-Ion Batteries

Sodium-ion batteries (SIBs) are emerging as a potential alternative to traditional lithium-ion batteries due to the abundant sodium resources. Carbon anodes, with their stable structure, wide availability, low cost, excellent conductivity, and tunable morphology and pore structure, exhibit outstanding performance in SIBs. This review summarizes the research progress of hard carbon anodes in SIBs, emphasizing the innovative paths and advanced performances achieved through multitrack optimization, including dimensional engineering, heteroatom doping, and microstructural tailoring. Each dimension of carbon material-0D, 1D, 2D, and 3D-offers unique advantages: 0D materials ensure uniform dispersion, 1D materials have short Na+ diffusion paths, 2D materials possess large specific surface areas, and 3D materials provide e-/Na+ conductive networks. Heteroatom doping with elements such as N, S, and P can tune electronic distribution, expand interlayer spacing of carbon, and induce Fermi level shifts, thereby enhancing sodium storage capability. In addition, defect engineering improves electrochemical performance by modifying graphitic crystal structure. Furthermore, suitable pore structure design, particularly closed pore structures, can increase capacity, minimizes side reactions, and suppress degradation. In future studies, optimizing morphology design, exploring heteroatom co-doping, and developing environmentally friendly, low-cost carbon anode methods will drive the application of high-performance and long cycle life SIBs.

Optimizing Hard Carbon Anodes from Agricultural Biomass for Superior Lithium and Sodium Ion Battery Performance

Biomass-derived carbon materials are gaining attention for their environmental and economic advantages in waste resource recovery, particularly for their potential as high-energy materials for alkali metal ion storage. However, ensuring the reliability of secondary battery anodes remains a significant hurdle. Here, we report Areca Catechu sheath-inner part derived carbon (referred to as ASIC) as a high-performance anode for both rechargeable Li-ion (LIBs) and Na-ion batteries (SIBs). We explore the microstructure and electrochemical performance of ASIC materials synthesized at various pyrolysis temperatures ranging from 700 to 1400 °C. ASIC-9, pyrolyzed at 900 °C, exhibits multilayer stacked sheets with the highest specific surface area, and the least lateral size and stacking height. ASIC-14, pyrolyzed at 1400 °C, demonstrates the most ordered carbon structure with the least defect concentration and the highest stacking height and an increased lateral size. ASIC-9 achieves the highest capacities (676 mAh/g at 0.134 C) and rate performance (94 mAh/g at 13.4 C) for hosting Li+ ions, while ASIC-14 exhibits superior electrochemical performance for hosting Na+ ions, maintaining a high specific capacity after 300 cycles with over 99.5 % Coulombic efficiency. This comprehensive understanding of structure-property relationships paves the way for the practical utilization of biomass-derived carbon in various battery applications.

Doping Engineering in Electrode Material for Boosting the Performance of Sodium Ion Batteries

In recent years, sodium ion batteries (SIBs) emerged as promising alternative candidates for lithium ion batteries (LIBs) due to the high abundance and low cost of sodium resources. However, their commercialization has been hindered by inherent limitations, such as low energy density and poor cycling stability. To address these issues, doping methodology is one of the most promising approaches to boosting the structural and electrochemical properties of SIB electrodes. This review provides a comprehensive overview of recent advancements in doping strategies, focusing on the improvement of the performance of SIBs. Various dopants including s- and p-block elements, transition metals, oxides, carbonaceous materials, and many more dopants are discussed in terms of their effects on enhancing the electrochemical properties of SIBs. Furthermore, the mechanisms responsible for the improvement in the performance of doped SIBs materials are also discussed. It also highlights the importance of doping sites in the crystal lattice, which also play a crucial role in doping in optimizing electrode structure, enhancing ion diffusion kinetics, and stabilizing electrode/electrolyte interfaces. The review ends by looking at the recent studies in simultaneous multiple heteroatom doping, offering valuable perspectives for a high performance SIB. This study provides valuable insight into the researchers and battery industries striving for advancements in energy storage technologies.

Preparation of nitrogen doped hyper-crosslinked polymer-based hard carbon for high performance Li+/Na+ battery anode

Hyper cross-linked polymers (HCPs), as a key precursor of hard carbon (HC) anode materials, stand out because of their capacity for molecular-scale structural design and comparatively straightforward preparation techniques, which are not seen in other porous materials synthesized procedure. A novel synthesis method of HCPs is developed in this paper, which is through the incorporation of functional macromolecules, the structural control and heteroatom doping of the product has been achieved, thus augmenting its electrochemical performance in batteries. In this work, carbonized tetraphenylporphyrin zinc (TPP-Zn) doped HCP-based hard carbon (CTHCP) with stable structure was prepared by Friedel-Crafts reaction and carbonization by using naphthalene and trace TPP-Zn as monomers, dimethoxybenzene (DMB) as crosslinking agent and FeCl3 as catalyst. The introduction of TPP-Zn, a functional macromolecule with unique two-dimensional structure, realized the pore structure regulation and N doping of the raw carbonized HCP-based hard carbon (CHCP). The results showed that CTHCP had higher mesoporous volume, N content and wider layer spacing than CHCP. In addition, CTHCP anode exhibited excellent Li+/Na+ storage performance, initial reversible capacity, rate performance and long cycle life. More amount of N-containing (N-5) active sites and mesoporous content in CTHCP anode was the main reason for the improvement of Na+ storage effect. While the increased interlayer spacing had a greater effect on the lithium storage capacity. This study uncovered the design rules of HC anode materials suitable for Li+/Na+ batteries and provided a new idea for the preparation of high-performance HC anode materials.

High-Efficiency Electroreduction of Nitrite to Ammonia on Ni Nanoparticles Strutted 3D Honeycomb-Like Porous Carbon Framework

Electroreduction of nitrite (NO2 - ) to ammonia (NH3 ) provides a sustainable approach to yield NH3 , whilst eliminating NO2 - contaminants. In this study, Ni nanoparticles strutted 3D honeycomb-like porous carbon framework (Ni@HPCF) is fabricated as a high-efficiency electrocatalyst for selective reduction of NO2 - to NH3 . In 0.1 M NaOH with NO2 - , such Ni@HPCF electrode obtains a significant NH3 yield of 12.04 mg h-1  mgcat. -1 and a Faradaic efficiency of 95.1 %. Furthermore, it exhibits good long-term electrolysis stability.

Effective reinforcement of plasticized starch by the incorporation of graphene, graphene oxide and reduced graphene oxide

Plasticized starch (PLS) nanocomposite films using glycerol and reinforced with graphene (G) and graphene oxide (GO) were prepared by solvent casting procedure. On one hand, the influence of adding different G contents into the PLS matrix was analyzed. In order to improve the stability of G nanoflakes in water, Salvia extracts were added as surfactants. The resulting nanocomposites presented improved mechanical properties. A maximum increase of 287 % in Young's modulus and 57 % in tensile strength was achieved for nanocomposites with 5 wt% of G. However, it seemed that Salvia acted as co-plasticizer for the PLS. Moreover, the addition of the highest G content led to an improvement of the electrical conductivity close to 5 × 10-6 S/m compared to the matrix. On the other hand, GO was also incorporated as nanofiller to prepare nanocomposites. Thus, the effect of increasing the GO content in the final behavior of the PLS nanocomposites was evaluated. The characterization of GO containing PLS nanocomposites showed that strong starch/GO interactions and a good dispersion of the nanofiller were achieved. Moreover, the acidic treatment applied for the reduction of the GO was found to be effective, since the electrical conductivity was 150 times bigger than its G containing counterpart.

First-principle computation of some physical properties of half-Heusler compounds for possible thermoelectric applications

Using the density functional theory (DFT) method, we investigate the properties of LaXSi (X = Pt, Pd) half-Heusler compounds. To ensure the stability of both compounds, we employed two criteria: the Birch-Murnaghan equation of state and the negative formation energy. The evaluation of elastic constants (ECs) plays a crucial role in determining the mechanical stability of both compounds. Specifically, we ensure that the conditions C11 - C12 > 0, C11 > 0, C11 + 2C12 > 0, and B > 0 are satisfied and exhibit mechanical anisotropy and ductility. The analysis of electronic properties clearly indicates that LaPtSi displays metallic behavior in both the spin-up and spin-down states. In the spin-up state of LaPdSi, a band gap is observed, which indicates its characteristic of being a half-metal. A comprehensive investigation of optical properties revealed that these compounds display notable absorption and optical conductivity at higher energy levels. Conversely, they exhibit transparency to incident photons at lower energy levels. Based on the findings, it can be concluded that these compounds are highly suitable for application in high-frequency UV devices. The thermoelectric properties clearly indicate that both materials exhibit high power factors, electrical conductivity, and figures of merit (ZT), suggesting their potential as exceptional thermoelectric materials. The simulations conducted in this study consider the effect of on-site Coulomb interactions by incorporating the Hubbard U term within the GGA + U. Our findings contribute valuable insights that can facilitate further experimental investigations and provide comprehensive validation.

The ability of twisted nanographene for removal of Pb2+, Hg2+ and Cd2+ ions from wastewater: Computational study

CONTEXT

Heavy metal ion removal from wastewater has become a global concern due to its extensive negative effects on human health and the environment. The density functional theory is employed to investigate the possibility of removing Pb2+, Hg2+, and Cd2+ ions from wastewater using nano-graphene. Researchers have shown that NG can efficiently remove heavy metals from media. Additionally, it was shown that the adsorption of Pb2+, Hg2+, and Cd2+ ions might reduce the large pristine NG (HOMO-LUMO) gap.

METHODS

HSE06 may accurately represent NG electrical characteristics. The DFT-D3 method was also used to account for Van der Waals interactions in the present study. The results demonstrated that charge transfer and binding energy remained greater in cation-NG systems with greater electron transfer rates. Pb2+, Hg2+, and Cd2+ adsorption results indicated that Egap was significantly reduced by 68%, 15%, and 21%, respectively. The Pb2+@NG complex exhibited the strongest oscillator strength. This may be explained by the enormous occupation number difference between the 2px orbital of the C atoms and the 6 s orbital of the Pb2+ cations. The greater Ebin value of Pb2+@NG is consistent with the increased predicted redshifts (199 nm). DFT (hybrid functional HSE06) studies that rely on time showed that the relevant complexes have "ligand-to-metal charge transfer" excitations. In general, it was found that Pb2+@NG had the greatest k value, binding energy, redshifts, and charge transfer rate among the complexes. The theoretical insights of this study may influence experimental efforts to identify NG-based compounds that are effective and efficient at removing pollutants from wastewater.