Enhanced electrochemical performance of the LiMn_0.6Fe_0.4PO₄/C modified by secondary particle morphology control combined with primary particle size control

Bowl-shaped LiMn_0.6Fe_0.4PO₄/C composites were created in this search with the use of hexadecyl trimethyl ammonium bromide (CTAB) as the organic carbon source, dispersion, and reductive agent in a carbothermal reduction process. The homogeneous coating of amorphous carbon on the primary particles made possible by the use of CTAB inhibits the overgrowth of primary particles throughout the synthesis process. Moreover, the difficulty of the droplet to maintain a spherical shape causes deformation when droplet size, density, and surface tension are reduced, and the deformation of the droplets’ original spherical shape can be attributed to the bowl-shaped morphology. The bowl-shaped secondary particles could further increase the specific surface area of LiMn_0.6Fe_0.4PO₄/C composites. The smaller primary particles and bowl-shaped secondary particles shorten the Li⁺ transport channel and increase the number of Li⁺ transport sites. All these factors contribute to the outstanding specific capacity (159.2 mAh g⁻¹ at 0.1 C and 108.8 mAh g⁻¹ at 15 C) and considerable cycling stability (95.1% of capacity retention after 1000 cycles at 1 C).