Synthesis and optimization of three-dimensional lamellar LiFePO 4 and nanocarbon composite cathode materials by polyol process

Enhanced electrochemical performances of LiFePO4-C synthesized with PEG as the grain growth inhibitor for Li-ion capacitors in LiNO3 aqueous electrolyte

“…With the further increase of the calcination temperature, undesirable particle growth is seen, leading to heterogeneous larger particles. These results suggest that the crystallinity and particle size of LFP could be improved by adjusting the calcination temperature, which may have effects on the electrochemical performance of the composites (Lu et al , 2016; Kim et al , 2007).…”

A novel “holey-LFP / graphene / holey-LFP” sandwich nanostructure with significantly improved rate capability for lithium storage

“…where R, T, A, n, F, C respectively represent the gas constant, absolute temperature, surface area of the cathode, charge transfer number of, Faraday constant, Li + concentration, and σ is the Warburg factor related to the angular frequency ω and the imaginary impedance (-Zim/Ω) based on the formula (2) [15,18]:…”

“…In general, the electrochemical performance/cost of LIBs depend mainly on the utilized component materials and especially that on the positive electrode [1]. LiFePO4 (LFP) is a competitive candidate for the positive electrode, primarily due to the advantages of high specific capacity, long cycle life, high safety, low price and no poison [13][14][15][16].…”

“…To solve the transport limitations of ion and electron, numerous works have been reported, including heteroatom doping [18][19], particle size optimizing [20][21] and micro-sturcture design [22][23][24], and coating with conductive layers (conductive polymer, metal oxide or carbonaceous nanomaterials) [15,[22][23][24][25][26]. These strategies can enhance the Li storage performance of LFP, for instance, when the nanoscale LFP particle is used, an effectively enhanced specific capacity has been demonstrated.…”

“…Graphene demonstrates a lot of outstanding chemical/physical attributes and possesses intriguing advantages as a conductive reagent for electrode materials, mainly because of the tremendous specific surface area and high conductivity [7,[31][32][33]. The performances of electrode materials usually enhanced significantly when formed composites with graphene, and it has been reported that LFP/graphene composites displayed even better performance compared to the LFP/carbon black or nanotube composites [15,[23][24]. However, the Hummers method is commonly employed to prepare graphene oxide, and the subquent reduction process usually cause the re-stack of graphene oxide, resulting in substantial decrease of the surface area and deterioration of the utilization efficiency [34].…”