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A novel and facile strategy for fabricating red phosphorus@nitrogen doped graphene/carbon nanotube aerogel (P@NGCA) is proposed as a free-standing anode for high energy sodium-ion batteries. Owing to an optimized structure of red P uniformly confined in porous NGCA with high conductivity and mechanical stability, the free-standing P@NGCA anode exhibits outstanding sodium storage performance with a high areal capacity of 3.3 mA h cm−2 and superior initial Coulombic efficiency of 80%. [ABSTRACT FROM AUTHOR]

A paper-based membrane coated by graphitic carbon nitride (g-C3N4) is prepared via a dip-coating method and used as a separator for sodium metal batteries with merits of low cost and environment-friendliness. Introduction of g-C3N4 effectively improves the ionic conductivity and the structural stability of the separator. Compared with traditional polyethylene separators and Al2O3-coated separators, the g-C3N4-coated separators show better electrolyte wettability, thermal stability, and electrochemical stability. Therefore, Na||Na3V2(PO4)3 battery using the g-C3N4-coated separator exhibits better cycling stability and higher rate capability. These results prove that the g-C3N4-coated paper-based separator is expected to become the next generation of low-cost and high-safety separator in sodium metal batteries. [ABSTRACT FROM AUTHOR]

We prepare a totally nonflammable phosphate-based electrolyte composed of 5 mol L−1 (M) Li bis(fluorosulfonyl) imide (LiFSI) in a trimethyl phosphate (TMP) solvent. The concentrated 5 M LiFSI/TMP electrolyte shows good compatibility with graphite and no Al corrosion. More attractively, such a concentrated electrolyte can effectively suppress the growth of Li dendrites in Li metal batteries because of a stable LiF-rich SEI layer. Therefore, this highly concentrated electrolyte is promising for safe Li batteries. [ABSTRACT FROM AUTHOR]

Abstract: Sodium‐ion batteries (SIBs) have a promising application prospect for energy storage systems due to the abundant resource. Amorphous carbon with high electronic conductivity and high surface area is likely to be the most promising anode material for SIBs. However, the rate capability of amorphous carbon in SIBs is still a big challenge because of the sluggish kinetics of Na+ ions. Herein, a three‐dimensional amorphous carbon (3DAC) with controlled porous and disordered structures is synthesized via a facile NaCl template‐assisted method. Combination of open porous structures of 3DAC, the increased disordered structures can not only facilitate the diffusion of Na+ ions but also enhance the reversible capacity of Na storage. When applied as anode materials for SIBs, 3DAC exhibits excellent rate capability (66 mA h g−1 at 9.6 A g−1) and high reversible capacity (280 mA h g−1 at a low current density of 0.03 A g−1). Moreover, the controlled porous structures by the NaCl template method provide an appropriate specific surface area, which contributes to a relatively high initial Coulombic efficiency of 75%. Additionally, the high‐rate 3DAC material is prepared via a green approach originating from low‐cost pitch and NaCl template, demonstrating an appealing development of carbon anode materials for SIBs. [ABSTRACT FROM AUTHOR]

Lithium iron phosphate battery recycling is enhanced by an eco-friendly N 2 H 4 ·H 2 O method, restoring Li+ ions and reducing defects. Regenerated LiFePO 4 matches commercial quality, a cost-effective and eco-friendly solution. [Display omitted] • Low-temperature liquid-phase direct regeneration of LiFePO 4 with high efficiency. • Li+ ions anti-site defects being repaired Using N 2 H 4 ·H 2 O. • Regenerated LiFePO 4 showing good electrochemical performance. Lithium iron phosphate batteries, known for their durability, safety, and cost-efficiency, have become essential in new energy applications. However, their widespread use has highlighted the urgency of battery recycling. Inadequate management could lead to resource waste and environmental harm. Traditional recycling methods, like hydrometallurgy and pyrometallurgy, are complex and energy-intensive, resulting in high costs. To address these challenges, this study introduces a novel low-temperature liquid-phase method for regenerating lithium iron phosphate positive electrode materials. By using N 2 H 4 ·H 2 O as a reducing agent, missing Li+ ions are replenished, and anti-site defects are reduced through annealing. This process restores nearly all missing Li+ ions at 80 °C/6h. After high-temperature sintering at 700 °C/2h, the regenerated LiFePO 4 matches commercial LiFePO 4 in terms of anti-site defects and exhibits excellent performance with a 97 % capacity retention rate after 100 cycles at 1C. Compared to high-temperature techniques, this low-temperature liquid-phase method is simpler, safer, and more energy-efficient, offering a blueprint for reclaiming discarded LiFePO 4 and similar materials. [ABSTRACT FROM AUTHOR]

Along with the cathode, anode, and liquid electrolyte in lithium-based secondary batteries, the separator is a crucial element for guaranteeing battery safety. However, conventional polyolefin separators suffer from inherent drawbacks such as inadequate compatibility with electrolytes and limited thermal stability. These limitations can lead to issues like high-temperature shrinkage, melting, and even combustion. Moreover, the vulnerability of separators toward lithium dendrite penetration exacerbates safety concerns associated with lithium-ion batteries. Hence, the design of high safety separators is currently a focus and challenge. In this study, we develop a multifunctional polymer-coupled nanofiber membrane by an electrospinning method that addresses the above issue as a separator of lithium metal battery. The nanofiber coating contains carbonyl oxygen, pyrrole nitrogen, and cross-linked networks with tertiary amine groups. These components effectively neutralize acidic compounds generated during the liquid electrolyte side reaction. X-ray micro-computed tomography analysis verifies the exceptional structural stability of the new separator, maintaining its 3D skeleton even after 2000 h of cycling. The nanofiber separator in a full Li||NCM811 cell achieves a high specific capacity of 136.6 mA h g−1 at 0.9 A g−1 and displays outstanding long-cycle stability over 500 cycles with a capacity retention of 88.5%. [Display omitted] • The membrane contains cross-linked networks featuring tertiary amine groups. • Highly porous and stable separator morphology is quantified via CT tomography. • The battery using the separator has a high capacity retention (88.5%) after 500 cycles. [ABSTRACT FROM AUTHOR]

The Co 9 S 8 -C-Li 2 S synthesized via synchronous carbothermal reduction process can not only reduce the cost, decline the activation voltage, but also significantly inhibit the shuttle effect of Li 2 S-based Li-ion-S battery. [Display omitted] • Co 9 S 8 -C-Li 2 S composite is synthesized in-situ by synchronous carbothermal reduction of cheap sulfate. • The as-prepared Co 9 S 8 -C-Li 2 S composite has lower price and smaller particle size compared to the commercial Li 2 S. • The introduction of the Co 9 S 8 significantly reduces the activation voltage and effectively inhibits the "shuttle effect". An economic and convenient synchronous carbothermal reduction is introduced to prepare Co 9 S 8 -C-Li 2 S composite as cathode material for Li-ion-S battery. The synthesized Co 9 S 8 -C-Li 2 S composite greatly reduces the cost of Li 2 S cathode. Furthermore, small particles of Li 2 S and Co 9 S 8 are formed in-situ at the same time and distribute uniformly in carbon matrix. Meanwhile, the formation of the polar material Co 9 S 8 effectively inhibits the "shuttle effect", regulates the electrochemical reaction between Li 2 S and S, and significantly reduces the activation voltage of Li 2 S. As a result, Li-ion-S battery with Co 9 S 8 -C-Li 2 S cathode exhibits a lower active voltage of 2.5 V and a higher initial charge specific capacity of 1166 mA h g−1. [ABSTRACT FROM AUTHOR]