Self‐Assembly of Antisite Defectless nano‐LiFePO₄@C/Reduced Graphene Oxide Microspheres for High‐Performance Lithium‐Ion Batteries

Abstract

LiFePO @C/reduced graphene oxide (rGO) hierarchical microspheres with superior electrochemical activity and a high tap density were first synthesized by using a Fe -based single inorganic precursor (LiFePO OH@RF/GO; RF=resorcinol-formaldehyde, GO=graphene oxide) obtained from a template-free self-assembly synthesis followed by direct calcination. The synthetic process requires no physical mixing step. The phase transformation pathway from tavorite LiFePO OH to olivine LiFePO upon calcination was determined by means of the in situ high-temperature XRD technique. Benefitting from the unique structure of the material, these microspheres can be densely packed together, giving a high tap density of 1.3 g cm , and simultaneously, defectless LiFePO primary nanocrystals modified with a highly conductive surface carbon layer and ultrathin rGO provide good electronic and ionic kinetics for fast electron/Li ion transport.

Coral-shaped porous LiFePO4/graphene hybrids for high rate and all-climate battery applications

“…Compared to the control group (LiFePO4-C), the ID/IG of the PHLG is lower and the band attributed to the symmetric PO 4 -3 (948 cm _ 1 ) is weak, indicating that LiFePO4 particles are well covered by the graphene sheets and carbon coating layers [39,45]. The low value of ID/IG (0.872) of the PHLG hybrids indicate a highly ordered graphene structure and suggests that GO was successfully converted to thermally reduced graphene-sheets, which can lead to the increased electronic conductivity of the composites.…”

“…However, the effect of graphene additives to the electrochemical properties of simple designed LiFePO4-graphene hybrids is limited as it can only partially improve the electronic conductivity of the cathode. On the other side, there is rarely any work addressing the low temperature performance of the LiFePO4-graphene cathode as so far [38][39][40][41][42]. Thus, the feasibility of using more complex LiFePO4-graphene structure to improve Li + and etransport at low temperature still needs elaboration.…”

Application of H4P2O7 as leaching acid in one-step selective recovery for metals from spent LiFePO4 batteries

“…The four peaks attributed to Fe 2+ are observed at 709.8, 713.5, 724.3, and 727.3 eV. The peak located at 715.2 eV is assigned to Fe 3+ [37][38][39][40]. However, the intensity of this peak is detected to be weakened in the spectra of the residual cathode power after heat treatment, as shown in Fig.…”

Structural tuneability and electrochemical energy storage applications of resorcinol‐formaldehyde ‐based carbon aerogels

“…Introduction of conductive skeleton of RF/GO assisted in enhancing reaction kinetics by improving ionic and electronic conductivities results in retaining a high reversible capacity of 112 mAg À1 at current density of 1700mAg À1 , which is fifty times higher than the applied initial current density of 34 mAg À1. 137 In another study by Ning and co-workers where they successfully produced three dimensional interconnected highly porous conductive structured MoS 2 -NPC-NCNTs (molybdenum disulphide, N-doped polymeric carbon and N-doped carbon nanotubes) using facile two-step method with extraordinary physical, chemical and electrochemical properties as shown in Figure 14. Figure 13A shows the SEM image of the highly porous cross-linked structure of MoS 2 -NPC-NCNTs whereas Figure 13B shows the successful doping of nitrogen in both polymeric carbon and CNTs.…”