Bio-Synthesis of LiFePO4/C composites for lithium ion battery

According to the biomineralization assembly concept, high-performance LiFePO4/C composites are successfully obtained via an effective and controllable biomimetic sol-gel method. The key step of this method is using the Baker's yeast cells as structural templates and biocarbon sources. The phase identification of four different LiFePO4/C composites are tested by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which are used to research the morphology, size and structure of LiFePO4/C composites. And the electrochemical performance tests demonstrate when the amount of Baker's yeast cells are 20g L-1, LiFePO4/C composites exhibit the best discharge specific capacity, 151.6mAh g(-1) at 0.1C, which is higher than the pristine LiFePO4 electrode (116.8mAh g(-1) at 0.1C) without Baker's yeast cells. After 50 cycles at 0.1C, the discharge capacity maintains 147.8mAh g(-1) (97.5% of its initial value). Also, the sample LiFePO4/C with 20 g L-1 yeast cells shows a couple of redox peaks between 3.34V to 3.53V which is narrower and incisive, and the resistance is much smaller than other samples. Therefore the LiFePO4/C composites synthesized by yeast cells are an ideal type of cathode-active material for lithium ion batteries.