Hydrothermal synthesis of corn cob-like LiFePO4/C as high performance cathode material for lithium ion batteries

Abstract

Corn cob-like LiFePO₄ (LFP) cathode material was simply synthesized through hydrothermal method using block copolymer (PEG-PPG-PEG) as the surfactant. The influence of pH value and reaction time on the morphology of LFP has been briefly investigated. The presence of copolymer plays an important role in the construction of the hierarchically microstructures. By adjusting the pH value and reaction time, platelet-like, hexagram-like, porous spindle-like and corn cob-like LFP microstructures were obtained. To gain the cell performance of the synthesized LFP, galvanostatic charging-discharging measurement on the as-prepared samples were performed. The porous spindle-like LFP/C shows unexpected electrochemical performance since the spindle-like LFP have large structure which prevents access for the liquid electrolyte. Corn cob-like LFP/C exhibits the best electrochemical performance, discharge specific capacities of 120 mAh g^-1 after 100 cycles with capacity retention ratios of 80% at 0.1 C. This work also provides the possibility for further investigation into the shape-dependent electrochemical performance of other materials by optimizing the experimental parameters during hydrothermal synthesis.