A low external temperature method for synthesis of active electrode materials for Li batteries – Part B: Synthesis of lithium iron oxides Li x Fe y O z

Abstract

Anode materials for lithium-ion batteries based on iron oxides were synthesized using two different methods: a Low External Temperature Method (LETM) and a conventional Solid State Reaction Method (SSRM). Both methods lead to the formation of final products representing a mixture of two phases: approximately 75% LiFeO2 and 25% Li−xFe5O8 (0 < x ≤ 0.1). When compared with the ordinary solid state synthesis, LETM creates conditions for carrying out the synthesis at a lower external calcination temperature (200 °C) over a shorter period. The properties of the LixFeyOz obtained by the LETM were compared with those of the same compound obtained by SSR at 700 °C. Higher initial discharge capacity was displayed by the sample synthesized by the SSR method, while a superior cycling stability was shown by the sample synthesized by the LETM. The latter shows approximately double capacity at the 30th cycle as compared with the sample synthesized by SSRM.