Re-considering the LiMn1-xFexPO4/C cathodes utilized in electric vehicles

Abstract

Olivine-phosphate cathodes re-attract enormous attentions due to their excellent thermal stability when the electric vehicles encountered the various combusting accidents. In contrast to LiFePO4, lithium manganese iron phosphate is more promising cathode due to advantages of good safety and high-energy. Here, we reinvestigate the energy-output of LiMn1-xFexPO4/C (x = 0.05, 0.1, 0.15, 0.2, and 0.3) which is synthesized via the developed DMSO-assisted co-precipitation method. Among the synthesized samples, the energy density reaches the highest value using LiMn0.8Fe0.2PO4/C and then diminishes as Mn ratio further augmenting. Beside working as the individual cathode, the addition of 2% LiMn0.8Fe0.2PO4/C improves the cyclic stability of LiNi0.88Co0.09Al0.03O2 electrodes from 77 to 88% after 100 cycles without sacrificing energy density. Obviously LiMn0.8Fe0.2PO4/C could be directly utilized as the individual cathode to replace LiFePO4 and as the additive to improve the cyclic stability of Ni-rich cathodes.