Factor affecting rate performance of undoped LiFePO4

Nanoparticle shapes of LiMnPO4, Li+ diffusion orientation and diffusion coefficients for high volumetric energy Li+ ion cathodes

“…S3). We assume that this is similar to the reported micron-sized secondary composite agglomeration which improves the tap density of LiFe 0.6 Mn 0.4 PO 4 /C and LiFePO 4 /C, resulting in higher volumetric capacities of LiFe 0.6 Mn 0.4 PO 4 and LiFePO 4 [26,40,45].…”

Synthesis, electrochemical properties, and characterization of LiFePO4/C composite by a two-source method

“…The main problem with this material is poor rate capability, which is attributed to its low electronic conductivity and slow kinetics of lithium ion diffusion through the LiFePO 4 /FePO 4 interfaces [15,16]. Three main methods that have been adopted to improve the conductivities of LiFePO 4 are listed below: (i) coating with high conductivity materials like carbon or metal; (ii) doping with supervalent ions such as Mg 2+ , Al 3+ , Zr 4+ , Nb 5+ or W 6+ [17][18][19][20]; and (iii) adding carbon into LiFePO 4 by carbothermal reduction [21,22]. Recently the impurity Fe 2 P in LiFePO 4 was suggested to have a more important role in increasing electronic conductivity than did the doping ions [23,24].…”

Effect of sintering time on the physical and electrochemical properties of LiFePO4/C composite cathodes

“…The smaller particle sizes shorten the path of Li + diffusion and improve the diffusion velocity of Li + . It should be noted, however, that faster diffusion of lithium ions across the LiFePO 4 /FePO 4 two-phase boundary is only one factor improving the electrochemical kinetics of this material [8][9][10][11]. Other factors such as electronic conductivity, carbon distribution, particle homogeneity, etc., also affect its electrochemical kinetics directly or indirectly.…”

“…Moreover, divalent iron compounds, such as iron(II) oxalate, FeC 2 O 4 ·H 2 O, iron(II) acetate, Fe(OOCCH 3 ) 2 , were used as the starting material to synthesize LiFePO 4 . Apart from being expensive and involving the evolution of unfavorable gases, the several recalcinations and subsequent regrindings required to improve the homogeneity of the final products are not considered commercially favorable [10][11][12]. Therefore, a proper synthesis method developed to prepare pure, homogeneous carbon-coated LiFePO 4 powders with smaller particle size is an urgent research project.…”