Nano-structured red phosphorus/porous carbon as a superior anode for lithium and sodium-ion batteries

Abstract

To enhance electrochemical performance of lithium or sodium-ion batteries (LIBs or NIBs), active materials are usually filled in porous conductive particles to produce anode composites. However, it is still challenging to achieve high performance anode composites with high specific capacity, excellent rate performance, high initial Coulombic efficiency (ICE) and long cycle life. Based on these requirements, we design and fabricate activated carbon-coated carbon nanotubes (AC@CNT) with hierarchical structures containing micro-and meso-pores. A new structure of phosphorus/carbon composite (P@AC@CNT) is prepared by confining red P in porous carbon through a vaporization-condensation-conversion method. The micro-pores are filled with P, while the meso-pores remain unoccupied, and the pore openings on the particle surface are sealed by P. Due to the unique structure of P@AC@CNT, it displays a high specific capacity of 1674 mA h g −1 at 0.2 C, ultrahigh ICE of 92.2%, excellent rate performance of 1116 mA h g −1 at 6 C, and significantly enhanced cycle stability for LIBs. The application of P@AC@CNT in NIBs is further explored. This method for the fabrication of the special composites with improved electrochemical performance can be extended to other energy storage applications.

Mild‐Temperature Solution‐Assisted Encapsulation of Phosphorus into ZIF‐8 Derived Porous Carbon as Lithium‐Ion Battery Anode

“…A general strategy is to physically deposit RP in the carbon hosts via an evaporation/condensation process. [ 5–19 ] Note that a necessary high temperature of 500–900 °C is commonly applied in order to ensure the conversion of the bulk RP into the gas phase. In this process, RP sublimates and diffuses in the carbon hosts and finally form a carbon/RP composite.…”

“…[ 5 ] Moreover, the unstable, toxic, and flammable white phosphorus will also generate accompanied with the evaporation/condensation process, generally requiring further annealing thereafter washing with toxic CS 2 . [ 5–19 ] Recently, a solution‐processed encapsulation method has been developed to facilitate the formation of RP nanoparticles inside MWCNTs and meanwhile allow the easy removal of the external phosphorus anchored on the outer wall of MWCNTs because this solution‐based process avoids the formation of crystalline RP, and finally the phosphorus@MWCNTs hybrids exhibited a significantly improved cycling stability. [ 20 ]…”

“…Ideally, porous carbon hosts not only provide enough vacant space to confine RP, but also ameliorate electrical conductivity. So far, CNTs/MWCNTs, [ 5–9 ] graphene, [ 9–13 ] carbon nanofibers, [ 14,15 ] and some carbonaceous materials derived from biomass and organic precursors have been reported as porous carbon hosts for loading RP. [ 14–19 ] Among them, metal–organic frameworks (MOFs) derived porous carbons have attracted much interest due to their outstanding advantages such as controllable and high porosity, good thermal/chemical stability, high electrical conductivity, as well as easy modification with other elements and materials, etc.…”

“…Since the P 5 − anion is the main form of PP in ZIF‐8‐C@PP, the delithiation peak is unimodal rather than multiple, for example, three or more peaks can usually be detected during the traditional conversion of the Li x P phase to Li y P intermediates (1 ≤ y ≤ x ≤ 3) and finally to P. The polarization curve (Figure 4c) of ZIF‐8‐C @ PP anode is also not typical for phosphorus anode materials because PP was obtained by chemical etching instead of physical evaporation‐deposition. [ 7,17,20 ] Figure 4b shows the electrochemical impedance spectroscopy (EIS) of RP, ZIF‐8‐C, and ZIF‐8‐C@PP at an open circuit potential. All their Nyquist plot curves consist of a semicircle and a line from high frequency to low frequency, indicating that their electrochemical kinetics are subject to the control of both charge and mass transfer.…”

A facile grinding approach to embed red phosphorus in N,P-codoped hierarchical porous carbon for superior lithium storage

“…As shown in Fig. 2b, the three peaks in Raman spectrum of red P in the range of 300-500 cm −1 can be assigned to B1 fundamental mode, A1 symmetric stretch motion and E1 degenerate mode [14,26]. While in P@NPHPC composite, these typical peaks of red P disappeared, and only the D band (~1330 cm −1 ) and G band (~1590 cm −1 ) of carbon were detected, which was assignable to the generation of smaller-particle size and amorphous red P after grinding [17,23].…”