Phosphorus Particles Embedded in Reduced Graphene Oxide Matrix to Enhance Capacity and Rate Capability for Capacitive Potassium‐Ion Storage

Abstract

Early studies indicate that graphite is feasible as the negative electrode of a potassium-ion battery, but its electrochemical performance still cannot meet the demands of applications. More efforts should be focused on increasing the specific capacity and improving the rate capability in the meantime. Thus, stainless-steel autoclave technology has been utilized to prepare phosphorus nanoparticles encapsulated in reduced graphene oxide matrix as the electrode materials for a potassium-ion battery. As a result, the composite matrix affords high reversible capacities of 354 and 253 mA h g at 100 and 500 mA g , respectively. The superior electrochemical performance is mainly because the composite matrix possesses better electronic conductivity and a robust structure, which can promote the electron-transfer performance of the electrode. Furthermore, phosphorus particles can contribute to the high capacity through an alloying mechanism. In addition, the silklike, ultrathin, film composite with a high surface area is conducive to capacitive potassium-ion storage, which plays a more important role in rate performance and a high current density capability.

Mosaic Red Phosphorus/MoS2 Hybrid as an Anode to Boost Potassium‐Ion Storage

“…Figure 3b shows the high-resolution P 2p spectrum, the fitted peaks located at 134.9 and 130.4 eV are assigned to P 2p 3/2 and P 2p 1/ 2 , respectively. [4] Two characteristic peaks located at 229.5 and 232.6 eV in the high-resolution Mo 3d spectrum ( Figure 3c) could be attributed to Mo 3d 5/2 and Mo 3d 3/2 , respectively, confirming the presence of Mo 4 + in the RP/MoS 2 (2 : 1) hybrid. [21] Meanwhile, the lower-energy peak at 226.6 eV corresponds to S 2 s. [22] According to the high-resolution S 2p spectrum (Figure 3d), the S 2p 3/2 and S 2p 1/2 peaks located at 162.4 and 163.5 eV indicated the presence of S 2À in the RP/MoS 2 (2 : 1) hybrid.…”

“…obtained a phosphorus/carbon composite by a simple ball‐milling method which showed a much higher capacity with 323.5 mAh g −1 after 50 cycles at a current density of 50 mA g −1 in KIBs. Wang et al . also gained a P@RGO composite with a capacity of 354 mAh g −1 after 50 cycles at 100 mA g −1 .…”

“…Unfortunately, some demerits such as the inferior electrical conductivity, large polarization, and drastic volume expansion still impede the commercial application of KIBs. Hence, a diversity of innovations are being attempted to boost the K + storage capability of RP, such as fabricating black phosphorus, [3] making RP particles embed in graphite matrix, [4] confining phosphorus in mesoporous carbon skeleton, [5] forming various metallic phosphides (Sn 4 P 3 /C, [6] GeP 5 , [7] and CoP [8] et al), combining RP with diverse carbonaceous materials (graphite, [4] CNTs, [5] mesoporous carbon [9] and activated carbon [10] et al) and constructing various architectures (such as core-shell, [8] tubular [11] and layered [12] structure). For example, Wu et al [13] obtained a phosphorus/carbon composite by a simple ballmilling method which showed a much higher capacity with 323.5 mAh g À 1 after 50 cycles at a current density of 50 mA g À 1 in KIBs.…”

“…For example, Wu et al [13] obtained a phosphorus/carbon composite by a simple ballmilling method which showed a much higher capacity with 323.5 mAh g À 1 after 50 cycles at a current density of 50 mA g À 1 in KIBs. Wang et al [4] also gained a P@RGO composite with a capacity of 354 mAh g À 1 after 50 cycles at 100 mA g À 1 . However, some pending technical dilemmas remain to be solved, including cycling durability and application compatibility during long-term cycles.…”

Highly Concentrated KTFSI : Glyme Electrolytes for K/Bilayered‐V2O5 Batteries

“…[8,14] So far, the investigation has focused on negative electrode materials. [19,20] In fact, numerous anode materials with high stability, capacity, and rate performance have been developed, such as carbonaceous materials, [21,22] transitional-metal dichalcogenides, [23][24][25] alloy materials, [26,27] phosphides, [11,28] and organic compounds. [10,29] On the other hand, the choice of positive electrode materials for PBs is very limited due to, among other reasons, the sluggish insertion kinetics resulting from the large K + ionic radius.…”