Synthesis of lithium mangan dioxide (LiMn2O4) for lithium-ion battery cathode from various lithium sources

Abstract

LiMn2O4 as a cathode material has been synthesized via solid state reaction. The synthesis has been done by varying lithium sources such as LiOH.H2O and Li2CO3 while MnO2 was used as Mn sources. All raw materials were mixed stoichiometrically to be the precursors of LiMn2O4. The precursors were sintered using high temperature furnace at 800 °C for 4 hours in atmospheric condition to form final product. The final products were sieved to separate the finer and smoother particles from the coarse ones. The products were characterized by X-Ray Diffractometer (XRD) to identify phases and crystal structure. The peak wave number was also determined using Fourier Transform Infra Red (FTIR) to find functional group. LiMn2O4 sheets were prepared by mixing active material with polyvinylidene fluoride (PVdF) and acetylene black (AB) in mass ratio of 85:10:5 wt.% in N,N-Dimethylacetamide (DMAc) solvents to form slurry. The slurry was then coated onto Al foil with thickness of about 0.15 mm and dried in an oven. LiMn2O4 sheet was cut into circular discs and arranged with separator, metallic lithium, and electrolyte in a coin cell. Automatic battery cycler was used to measure electrochemical performance and specific capacity of the cell. XRD analysis showed that sample synthesized with Li2CO3 has higher crystallinity and more pristine than sample synthesized with LiOH.H2O. FTIR analysis revealed that both of samples have identical functional group but sample with Li2CO3 source tend to degrade. Cyclic voltammetry data gave information that sample with LiOH.H2O source has better electrochemical performance. It showed double oxidation/reduction peaks more clearly but sample with Li2CO3 source has higher specific capacity (64.78 mAh/g) than sample with LiOH.H2O (50 mAh/g).