LiFePO₄ battery cathodes with combined polyaniline/carbon nanober additive.

Polyaniline (PANI), a conducting polymer, and carbon nanofibers (CNFs) were introduced as a combined additive to lithium ion battery cathodes. The PANI polymer is electrochemically active in the range of 2.0- 3.8 V, which overlaps the operative redox couple of LiFePO4. The combined properties of PANI and CNF show that the composite material can act not only as a host material for improving Li- ions intercalation but. also, as an agent for increasing overall battery conductivity. Electrochemical measurements showed that batteries fabricated with the combined LiFePO₄/PANI/CNF cathode material had superior high-rate performance at >5C capability rates when compared against batteries made using PANI or CNF as individual additives. The improvement can be attributed to an increase of, both, short-range and long-range conductivity.