Synthesis of LiCoO2 via sol-gel method for aqueous rechargeable lithium batteries

Abstract

A crystalline structure of LiCoO2 sample was synthesized at different stirring times via sol-gel method. This was followed by the electrochemical characterization of LiCoO2 in 5 M LiNO3 aqueous electrolyte. The hexagonal LiCoO2 was stirred for 30 h produced the highest peak intensity and smallest particle size. A morphological analysis showed the particle size distribution within the range of 0.32–0.47 μm. At lower scan rates of cyclic voltammetry, three pairs of redox peaks at ESCE = 0.81/0.65, 0.89/0.83 and 1.01/0.95 V were observed. The peak separation was proportionally consistent with Li+ diffusion coefficients of 7.42 × 10−8 cm2 s−1 (anodic) and 3.59 × 10−8 cm2 s−1 (cathodic). For specific capacity, the LiCoO2 demonstrated a higher initial specific capacity (115.49 mA h g−1). A small difference (1.92 Ω) in the charge transfer resistance before and after a charge discharge analysis indicated that the Li+ ions had been well-diffused during the intercalation/de-intercalation process.