Search

Designing Sb/carbon composite is an effective strategy to enhance the cycle stability and rate capability of Sb anodes for sodium ion batteries. However, the introduction of carbon often leads to a loss in specific capacity and initial Coulombic efficiency (ICE). In this work, a new perspective is adopted by focusing on improving the "sloping capacity" contribution of carbon (C) in Sb/C composites, rather than solely increasing the platform capacity of Sb as traditionally done. Theoretical predictions indicate that constructing Sb/C composites with high Sb and carbon interfacial areas can provide more Na adsorption sites, thus enhancing the "sloping capacity" of amorphous carbon. Guided by DFT, a rational Sb/C/NSCDs‐2(N) is successfully developed by self‐embedding Sb nanodots into 2D‐amorphous carbon sheets doped with N/S. Sb/C/NSCDs‐2(N) exhibits abundant Sb/carbon interfacial areas and excellent nanoscale effects, demonstrating ideal electrochemical sodium storage performances. Impressively, the Sb/C/NSCDs‐2(N) provides a "sloping capacity" close to 160 mAh g−1. Significantly, owing to the fact that these interfaces and defects are not in direct contact with the electrolyte, the side reaction of electrolyte is effectively inhibited, leading to no decrease of ICE. [ABSTRACT FROM AUTHOR]

Bi-doped carbon dots (Bi-CDs) with rich polar groups and good compatibility were employed as co-deposition electrolyte additives to homogenize Li+ flux for dendrite-free Li deposition. High coulombic efficiency (99.0%) and long-term stability (800 h) with reduced overpotential (∼15 mV) were achieved after introducing Bi-CDs in conventional electrolyte for high-performance Li–S batteries. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) are considered as excellent structural regulator for metal oxides (MOs) due to their abundant functional groups, superior dispersibility, and ultrasmall size (<10 nm). Herein, a new approach is proposed to construct porous pomegranate‐like MOs/CDs composite based on the CDs‐induced in situ growth mechanism of ion adsorption–multipoint surface nucleation–crosslinking agglomeration. The proposed methodology is successfully applied to prepare SnO2/CDs, Cu2O/CDs, and Fe2O3/CDs composites, respectively, demonstrating its universality to metal oxides. Taking SnO2/CDs composite as a case study for anode material in lithium‐ion batteries, it exhibits high lithium storage capacity, excellent cycling stability, and a special feature of capacity increase upon cycling. This study provides a new idea for the design of metal oxides materials tuned by CDs and broadens the application of CDs in the field of material synthesis. [ABSTRACT FROM AUTHOR]

Ringent hollow carbons synthesised by CDs through controllable reaction temperatures show great absorbing values and absorbing bands as well as relative compression ratios of radar cross section. Finite element simulation demonstrats that unique structure of ringent hollow carbons can lower normal reflected wave and promote energy attenuation which provides a new direction for the structural design of absorbers. [Display omitted] • A high-yield of carbon quantum dots derived ringent hollow carbon spheres (RHCs) for efficient microwave absorber has been proposed. • Outstanding microwave absorbing performance with optimal reflection loss of −67 dB as well as superior absorbing bandwidth (covering C, X and Ku band) could be achieved. • A relative compression ratio of 56.7 % of of RHCs loaded coating could be achieved due to ringent hollow structure and intrinsic nanosheets attenuation. Carbon nanomaterials have steadily grown into a class of composite absorbers with remarkable properties due to their unique structure, low density, high specific surface area, strong electrical conductivity, and substantial dielectric losses. In this paper, a facile strategy with low-cost, high-efficiency, and scalable strategy for carbon dots-derived ringent hollow carbon (RHC) for superior microwave absorption is proposed. Controllable structures ranging from amorphous carbon to ringent hollow carbon are well performed through simple heat-treated temperature. In addition, an optimal absorption value of −67 dB and a superior absorption band width covering the C, X, and Ku bands, as well as a relative compression ratio of 56.7 percent in the case of perpendicular incidence, have been achieved. Further, finite element simulations have demonstrated that the unique structure of partially ringent hollow carbon is considered as an effective way to lower normal reflected wave and promote energy attenuation. New applications of carbon dots-derived RHC as superior microwave absorbers are opening up, and the scalable strategy may pave a solid foundation for rapid applications. [ABSTRACT FROM AUTHOR]