A new methodology for the synthesis of carbon quantum dots (CQDs) for large production is proposed. The as-obtained CQDs can be transformed into 3D porous carbon frameworks exhibiting superb sodium storage properties with ultralong cycle life and ultrahigh rate capability, comparable to state-of-the-art carbon anode materials for sodium-ion batteries.

Ion occupation and migration pathways are investigated to explore the ion-migration mechanism of Na 3 V 2 (PO 4 ) 3 with the help of first principles calculations. Na 3 V 2 (PO 4 ) 3 with a NASICON framework generates high performances as a cathode material in sodium-ion batteries.

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Due to the high theoretical capacity of 946 mAh g(-1), Sb2S3 can be employed as promising electrode material for sodium-ion batteries (SIBs). Herein, the sodium storage behaviors of one-dimensional (1D) Sb2S3-based materials (Sb2S3 and Sb2S3@C rods) are successfully studied for the first time, displaying good cyclability and rate capability owing to their unique morphology and structure. Specifically, the Sb2S3@C rods electrode presents greatly enhanced electrochemical properties, resulting from the introduction of thin carbon layers which can effectively alleviate the strain caused by the large volume change and simultaneously improve the conductivity of electrode during cycling. At a current density of 100 mA g(-1), it delivers a high capacity of 699.1 mAh g(-1) after 100 cycles, which corresponds to 95.7% of the initial reversible capacity. Even at a high current density of 3200 mA g(-1), the capacity can still reach 429 mAh g(-1). This achievement may be a significant exploration for develpoing novel 1D Sb-based materials or metal sulfide SIBs anodes.

Sodium-ion batteries (SIBs) have come up as an alternative to lithium-ion batteries (LIBs) for large-scale applications because of abundant Na storage in the earth's crust. Antimony (Sb) hollow nanospheres (HNSs) obtained by galvanic replacement were first applied as anode materials for sodium-ion batteries and exhibited superior electrochemical performances with high reversible capacity of 622.2 mAh g(-1) at a current density of 50 mA g(-1) after 50 cycles, close to the theoretical capacity (660 mAh g(-1)); even at high current density of 1600 mA g(-1), the reversible capacities can also reach 315 mAh g(-1). The benefits of this unique structure can also be extended to LIBs, resulting in reversible capacity of 627.3 mAh g(-1) at a current density of 100 mAh g(-1) after 50 cycles, and at high current density of 1600 mA g(-1), the reversible capacity is 435.6 mAhg(-1). Thus, these benefits from the Sb HNSs are able to provide a robust architecture for SIBs and LIBs anodes.

N-doped TiO2 decorated with C-dots shows superior rate capability and extended battery life when utilized in Li-ion and Na-ion batteries.

Dark‐colored rutile TiO2 nanorods doped by electroconducting Ti3+ have been obtained uniformly with an average diameter of ≈7 nm, and have been first utilized as anodes in lithium‐ion batteries. They deliver a high reversible specific capacity of 185.7 mAh g−1 at 0.2 C (33.6 mA g−1) and maintain 92.1 mAh g−1 after 1000 cycles at an extremely high rate 50 C with an outstanding retention of 98.4%. Notably, the coulombic efficiency of Ti3+–TiO2 has been improved by approximately 10% compared with that of pristine rutile TiO2, which can be mainly attributed to its prompt electron transfer because of the introduction of Ti3+. Again the synergetic merits are noticed when the promoted electronic conductivity is combined with a shortened Li+ diffusion length resulting from the ultrafine nanorod structure, giving rise to the remarkable rate capabilities and extraordinary cycling stabilities for applications in fast and durable charge/discharge batteries. It is of great significance to incorporate Ti3+ into rutile TiO2 to exhibit particular electrochemical characteristics triggering an effective way to improve the energy storage properties.

couple high-capacity sulfur positive electrodes with earth-abundant sodium negative electrodes are unsurprisingly considered as a promising candidate. [8][9][10][11] In the process of cycle, the elemental sulfur of the cathode is dissolvated, reduced to form various soluble polysulfides, that is, S x 2− ions and radicals (1 ≤ x ≤ 8), and eventually the insoluble Na 2 S 2 and Na 2 S. [8,10,12] However, the practical applications are seriously hindered by several obstacles, in which the fundamental challenges are originated from the insulating properties of elemental sulfur and sodium sulfides, the volume changes at the cathode on cycling and the dissolution of sodium poly sulfides in the electrolyte. [9,[13][14][15] To date, extensive efforts have been made toward the enhancement of RT-Na/S batteries, including Na 2 S cathodes, [16,17] carbonaceous buffer matrixes, [12,18,19] a class of sodium polysulfides, [20,21] and the functional carbon-coated Nafion separator. [22] These approaches, while are validated to improve the cyclability of the RT Na-S batteries, tend to result in complicated synthetic processes and decreased theoretical capacity. In addition, it was suggested that the polar-polar interaction is a strong chemical interaction between polar sodium polysulfides and polar host materials. [23,24] Although there is no universal conclusion on the exact configuration of the interactions due to the complexity of carbon matrix, their similar effect in suppressing the polysulfide shuttle has also been reported in Li-S battery systems. [25][26][27] Instead of relying on polar-polar interactions, the suitably tailored hosts can bind sodium polysulfides through metal-sulfur bonding. Examples of such materials are sub-stoichiometric metal chalcogenides, MXene phases and metal-organic frameworks (MOFs). [28][29][30][31] In practice, these oxide and sulfide materials are able to bridge sodium polysulfides through both polar-polar Na-S(O) interaction and Lewis acid-base bonding, depending on the exposed facets to some extent. [25,32] However, to simply increase metal and/or binder content only neutralizes the advantageous energy density of the overall cell. Moreover, most of the sulfur-carbon electrode materials are directly prepared using elemental S and various carbon matrixes as started materials through vapor-infiltration or meltinfusion method. [8,10] As a result, the aggregated particles are Room temperature sodium-sulfur batteries have emerged as promising candidate for application in energy storage. However, the electrodes are usually obtained through infusing elemental sulfur into various carbon sources, and the precipitation of insoluble and irreversible sulfide species on the surface of carbon and sodium readily leads to continuous capacity degradation. Here, a novel strategy is demonstrated to prepare a covalent sulfur-carbon complex (SC-BDSA) with high covalent-sulfur concentration (40.1%) that relies on SO 3 H (Benzenedisulfonic acid, BDSA) and SO 4 2− as the sulfur source rather than elemental sulfur. M...