Influences of the surfactant on the performance of nano-LiMn2O4 cathode material for lithium-ion battery.

This study synthesized spinel LiMn 2 O 4 materials using a solid-state reaction processing technology. Neutral surfactants and the tri-block copolymer P123 (template) formed an organic self-assembly in alcohol (solvent), with LiCH 3 COO·2H 2 O and Mn(CH 3 COO) 2 ·4H 2 O as precursors of the inorganic skeleton. Changes in the structure, particle size, and surface area of LiMn 2 O 4 powder in relation to different surfactant contents were investigated. The changes in surface area should affect the wetting effect of the electrolyte on the cathode material, thereby further influencing the actual reaction area and charge–discharge efficiency. The results were analyzed to assess the effect of surface area on electrochemical performance of LiMn 2 O 4 cathode materials. X-ray diffraction (XRD) analysis data showed that LiMn 2 O 4 materials synthesized through the solid-phase reaction method are single-phase spinel, whose original structure is unaffected by the addition of surfactants. Scanning electron microscopic (SEM) observation revealed that LiMn 2 O 4 forms different spherical particles after the addition of different concentrations of surfactants. Furthermore, Brunauer–Emmett–Teller (BET) analysis showed that specific surface areas of 0.4–1.2 m 2 /g are relatively effective in enhancing the capacitance, similarly the formation of spherical particles is beneficial in enhancing the capacitance, and the high-current discharge efficiency is similar to the low-current discharge efficiency. As for the different concentrations of P123, the experiments added with 1.42 M P123 achieved optimum results. [ABSTRACT FROM AUTHOR]