Development of composites based on lithium manganese nickel oxide and electroactive polymers

A new composite cathode-active material based on lithium manganese nickel oxide (LiMn2−xNixO4), poly(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT) and polyaniline (PAni) was synthesized. The formation of the uniform and well-connected polymer film on the surface of LiMn2−xNixO4 particles was confirmed by Fourier-transform infrared spectra (FT-IR) and scanning electronic micrographs (SEM). The amounts of each constituent cannot be separately determined by thermogravimetric analysis (TGA). By galvanostatic charge–discharge tests, the PAni/PDMcT/LiMn2−xNixO4 composite showed a better electrochemical performance than each single component (PAni, PDMcT and LiMn2−xNixO4) and binary composites (PAni/LiMn2−xNixO4 and PDMcT/LiMn2−xNixO4). The electrical conductivity of the ternary composite reached 11.9 S cm−1 and an initial discharge capacity of 305 mAh g−1 was obtained. After 10 cycles, the coulombic efficiency and retention capacity was 99% and 90%, respectively. All results indicate a synergic effect among the materials in the composite.