Sodium‐ion batteries (SIBs) are emerging as promising alternatives to lithium‐ion batteries owing to the abundance of sodium resources and the limited supply of lithium raw materials. However, the development of high‐performance anode materials remains a critical challenge owing to the relatively low initial coulombic efficiencies (ICEs) and limited reversible capacities of conventional carbon‐based anodes. Herein, hard carbon (HC) from mangrove wood was synthesized via controlled carbonization, and its electrochemical performance was systematically investigated. HC prepared by carbonization at 1200 °C (MWHC‐1200) exhibited the best performance, delivering a high reversible capacity of 266.6 mAh g −1 and an ICE of 75%. Pitch‐derived soft carbon coatings (containing 5, 10, or 15 wt% pitch) were applied to HC synthesized at the optimal carbonization temperature to further enhance Na + ‐storage performance. Notably, the composite containing 10 wt% pitch (PC‐10) exhibited the best electrochemical performance, delivering a high reversible capacity of 291.5 mAh g −1 , an ICE of 82%, a capacity retention of 90.4% after 200 cycles, and an excellent rate capability. These improvements were associated with the suppression of irreversible reactions and improvement in interfacial stability. This study offers a simple yet effective approach for improving the electrochemical properties of biomass‐derived HC and provides insights into the design of practical SIB anodes.

Coal emerges as an exceptional candidate for hard carbon precursors, attributed to its three-dimensional (3D) structure and high carbon yield. Nevertheless, abundant aromatic rings in coal tend to form a highly ordered graphitic structure after high-temperature carbonization, which hinders sodium-ion (Na+) storage. Herein, glow discharge plasma is employed to effectively introduce oxygen-containing groups into coal effectively, facilitating the formation of a cross-linked structure, which is subsequently subjected to high-temperature carbonization to obtain structurally optimized coal-based hard carbon (HC). Compared with the traditional pre-oxidation method, the surface chemical composition and microstructure of coal-based HC (OCHC20) obtained after carbonized are effectively modified by oxygen plasma treatment. The OCHC20 exhibits a remarkable initial Coulombic efficiency (ICE) of 89.3% and a reversible capacity of 302mAhg- 1 at 0.05Ag-1, which is higher than the 263mAhg-1 reversible capacity of hard carbon (OCHC) prepared by traditional pre-oxidation. Particularly, OCHC20 displays superior rate performance with a capacity of 238mAhg-1 at 5Ag-1, representing a 22.7% increase over OCHC (194mAhg-1). This study demonstrates the potential of plasma technology in the rational design of carbon-based anodes for high-performance sodium-ion batteries (SIBs).

Inorganics from kraft black liquor enable rapid oxidative crosslinking and morphology control in lignin derived hard carbons.

Sodium-ion batteries (SIBs) are promising for large-scale energy storage, owing to their resource abundance and low cost. However, long-term stability is constrained by complex interfacial interactions and microstructural degradation. This study investigates the mechanistic coupling between anode composition, electrolyte chemistry, and solid electrolyte interphase (SEI) evolution in full-cell SIBs employing sodium vanadium phosphate (NVP) cathodes. Pure tin (Sn), hard carbon (HC), and Sn-HC composite anodes were systematically evaluated with carbonate ester- and ether-based electrolytes. Microscopic and spectroscopic analyses reveal that Sn-rich electrodes undergo significant pulverization and unstable SEI formation, whereas HC maintains structural integrity and forms kinetically stable SEI. On the other hand, the Sn-HC composite mitigates Sn's mechanical degradation while enhancing capacity retention. Electrochemical analysis highlights the critical role of electrolyte choice in modulating redox reversibility and interfacial integrity. Accelerating rate calorimetry (ARC) links interphase behavior to distinct thermal decomposition pathways and self-heating rate. These findings provide mechanistic insights into the electro-chemo-mechanical degradation processes dictating the long-term stability and thermal safety of SIBs.

Abstract To date, sodium hexafluorophosphate (NaPF₆) in carbonate solvents is the state-of-the-art electrolyte in sodium-ion capacitors (SIC). However, it possesses serious safety issues owing to its high fluorine content, and poor chemical and thermal stability, resulting in the formation of corrosive and hazardous byproducts. For this reason, its replacement with less fluorinated salt is considered of great importance for the development of sustainable SICs. In this work, we investigate the use of sodium bis(trifluoromethylsulfonyl)imide (NaTFSI) and sodium bis(fluorosulfonyl)imide (NaFSI), which are more sustainable and contain less mass percentage of fluorine compared to NaPF6 . The chemical-physical properties of electrolytes containing these salts dissolved in a mixture of ethylene carbonate and propylene carbonate was studied and compared to that of the state-of-art electrolyte. The use of these electrolytes in combination with hard carbon and activated carbons electrodes, in lab-scale SIC was thoroughly analysed. SICs containing these imide-based electrolytes exhibit far superior long-term stability compared to the state-of-the-art system. Furthermore, the degradation processes occurring in these innovative devices were investigated by X-ray photoelectron spectroscopy. The result of this study indicates that it is possible to realise high-performance SICs containing low fluorinated salts.

Abstract This study investigates two decades of surface biogeochemical change in the Mediterranean Sea (2001–2020) using the high-resolution Mediterranean biogeochemical reanalysis. This study focuses on monthly to decadal variations in the carbonate system, nutrients, and phytoplankton indicators, and includes a detailed assessment of coastal processes near the Po River mouth as one region with the highest variability in biogeochemical parameters. Basin-wide, surface dissolved inorganic carbon (DIC) and total alkalinity (TAlk) increased between 2001 and 2010 and 2011–2020 (DIC: 2277.78 to 2292.32 µmol/kg; TAlk: 2610.52 to 2623.47 µmol/kg), while surface partial pressure of CO₂ (spCO₂) rose from 41.23 to 42.72 Pa (+ 3.6%). These changes reflect enhanced CO₂ uptake and ongoing shifts in water-mass properties under a warming and stratifying climate. From 2011 to 2020 compared to 2001–2010, nutrient concentrations showed moderate declines (NO₃ −0.72%, NH₄ −1.16%, PO₄ −4.7%), accompanied by small decreases in chlorophyll-a (− 2.7%) and phytoplankton carbon (− 4.5%), consistent with basin-scale oligotrophication. The Po mouth analysis highlights the river’s regulatory role: discharge correlates positively with chlorophyll, NO₃, NH₄, PO₄, and phytoplankton carbon, but negatively with spCO₂, revealing nutrient-driven productivity pulses that locally enhance CO₂ drawdown. Overall, the Mediterranean surface layer suggests a possible dual behavior of carbon enrichment and nutrient depletion, reflecting a shift toward warmer, more stratified, and increasingly oligotrophic conditions. Graphical Abstract

Growing concerns over lithium cost and supply limitations have led to increasing interest in sodium-ion batteries (SIBs). However, hard carbon (HC) anodes suffer from low initial Coulombic efficiency due to irreversible sodium loss during the formation of the solid electrolyte interphase and ion trapping, which reduces the useable capacity in full-cell systems. Various sacrificial sodium sources have been investigated, but many generate gas, react with moisture, or degrade the cathode when they are mixed directly with it. In this study, we present a presodiation strategy based on a MnO@NaF composite (MNC) coated onto the cathode-facing side of the separator (MNCS). They are inexpensive, stable in air, and compatible with standard electrode fabrication processes. The MNC releases additional sodium through NaF decomposition catalyzed by MnO with negligible gaseous byproducts. By placing the MNC on the separator rather than on the cathode, the design avoids unwanted reactions while improving sodium availability and ion transport. When applied to a full cell with an O3-type Na[Li0.05(Ni0.25Fe0.25Mn0.5)0.95]O2 cathode and HC anode, the MNCS increased the initial discharge capacity to 169.5 mAh g-1 and maintained 69.5% of its capacity after 200 cycles. These results demonstrate the effectiveness of this approach in improving the available energy density and long-term stability in SIBs.

CO2 activation-induced closed pores in hard carbon derived from bamboo for enhanced sodium-ion storage.

Regulating local defect energy states of O3 type layered cathode materials for better sodium ion batteries.

Triple-engineered wood carbon for aqueous symmetrical supercapacitors: integrating fungal lignin removal, mild alkaline activation and carbon nanotube modification

Coupling of graphitic microcrystalline and available functional groups in hard carbon unlocking deep and fast potassium-ion storage

Influence of pyrolysis temperature on morphological features and electrochemical properties of cotton stalk-derived hard carbon materials

Hard carbon composites as high performance anode materials for alkali metal ion batteries: Advances and perspectives

Regulating lignin aggregation structure to construct high-performance hard carbon anodes for Sodium-Ion batteries

Synergistic integration of phosphorus doping and closed-pore architecture in starch-derived hard carbon for advanced sodium-ion storage

Achieving both large plateau capacity and high ICE of hard carbon via multi-steps of micropores tuning for high performance sodium ion batteries

Graphitic seeding strategy enables superior ICE, high capacity and rate capability in hard carbon anodes for sodium-ion batteries

Sorption behavior of 17α-Ethynylestradiol at the soil colloid/solution interface from different sources: Influence of organic/inorganic components and hydrochemical conditions.

Synergistic structural engineering and fluorine doping strategy in hard carbon for fast and stable potassium-ion storage

Regulating ultramicropores and closed-pores in starch-derived hard carbons for efficient sodium ion storage