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

LiFePO 4 @C/reduced graphene oxide (rGO) hierarchical microspheres with superior electrochemical activity and a high tap density were first synthesized by using a Fe 3+ ‐based single inorganic precursor (LiFePO 4 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 4 OH to olivine LiFePO 4 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 −3 , and simultaneously, defectless LiFePO 4 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.