Engineering graphene with red phosphorus quantum dots for superior hybrid anodes of sodium-ion batteries

Abstract

Red phosphorus (P) has been considered to be one of the most promising anode materials for sodium-ion batteries (SIBs) because of its highest theoretical capacity (∼2600 mA h g). For the first time, we report a reliable hydrothermal method for the preparation of red phosphorus quantum dots (RPQDs) with commercial red P as a source. Moreover, an effective strategy was designed to fabricate RPQDs/rGO nanohybrids for addressing the intrinsic issues of red P as anode materials for SIBs. Benefiting from the nanostructuring of red P and the coupling of RPQDs with rGO, the obtained nanohybrids not only promote electron and ion transfer, but also effectively enhance the electronic conductivity, restrain the aggregation of RPQDs and buffer the large volume changes of red phosphorus during the charge-discharge process. The nanohybrids deliver an initial specific capacity of 1161 mA h g and a low capacity deterioration rate of less than 0.12% per cycle even after 250 cycles at a current density of 200 mA g. The feasibility of large-scale production of the RPQDs/rGO nanohybrid, associated with its outstanding Na-ion storage properties and low cost, demonstrates that the RPQDs/rGO hybrid is a very promising anode material for SIBs.

Micro/Nanostructured Materials for Sodium Ion Batteries and Capacitors

“…Phosphorus (P) has a high theoretical capacity of ≈2600 mA h g −1 , corresponding to the formation of Na 3 P . Unfortunately, phosphorous also undergoes an enormous volume expansion similar to that of other alloying‐type anodes.…”

“…As a result, TiO 2 -Sn@CNFs delivered a high capacity of 413 mA h g −1 at 100 mA g −1 after 400 cycles. Phosphorus (P) has a high theoretical capacity of ≈2600 mA h g −1 , corresponding to the formation of Na 3 P. [111] Unfortunately, phosphorous also undergoes an enormous volume expansion similar to that of other alloying-type anodes. In addition, red P exhibits a natural insulating property with a low electrical conductivity of 1 × 10 −14 S cm −1 .…”

Bottom‐Up Construction of Conjugated Microporous Polyporphyrin‐Coated Graphene Hydrogel Composites with Hierarchical Pores for High‐Performance Capacitors

“…Meanwhile, a weak and broad diffraction peak located at 26.1° could also be detected, revealing the restacking of the conjugated graphene sheets for both the prepared materials. As delivered in Figure b, clear D band (1350 cm −1 ) and G band (1580 cm −1 ) together with two weak signals assigning to 2D bands at about 2700 and 2890 cm −1 , could be observed from the Roman spectrum of GH and GH‐CMP composites . The ratio of integral area (I D /I G ) is changed from 0.82 to 0.89 for the GH and GH‐CMP composites respectively, indicating the minor increasing defect level by the introduction of CMP.…”

“…As delivered in Figure 3b, clear D band (1350 cm À 1 ) and G band (1580 cm À 1 ) together with two weak signals assigning to 2D bands at about 2700 and 2890 cm À 1 , could be observed from the Roman spectrum of GH and GH-CMP composites. [15] The ratio of integral area (I D /I G ) is changed from 0.82 to 0.89 for the GH and GH-CMP composites respectively, indicating the minor increasing defect level by the introduction of CMP. However, the electrical conductivity could be maintained very well.…”

Carbon‐Based Alloy‐Type Composite Anode Materials toward Sodium‐Ion Batteries

“…The pioneering research on RP/G was conducted by Song et al, which delivers a high specific capacity of 2077 mAh g −1 with excellent cycling stability during 60 cycles . In addition to improving the conductivity, the graphene also favorites the uniform distribution of nanosized RP particles, significantly minimizing the sodium ion diffusion length and restraining the aggregation . Based on this advantage, Zeng et al decorated the RP quantum dots (QDs) with an average size of 4.0 nm on the graphene, which remained ≈900 mA h g −1 at 200 mA g −1 accompanying with a low capacity deterioration rate of less than 0.12% per cycle even after 250 cycles.…”