Octagonal prism shaped lithium iron phosphate composite particles as positive electrode materials for rechargeable lithium-ion battery

For the first time, octagonal prism shaped lithium iron phosphate (LiFePO4) composite particles supported on the multi-walled carbon nanotubes (MWNTs) (denoted as OP-LiFePO4/MWNTs) are prepared by using a boiling reflux assisted calcination method. Interestingly, spherical LiFePO4 composite particles (indexed as S-LiFePO4/C) are produced by the same procedure in the presence of activated carbon. It is observed that the edge length of OP-LiFePO4 particles is about 400 nm as compared to the particle size of S-LiFePO4 (∼150 nm) sample. Cyclic voltammetry (CV) tests demonstrate that at the scan rate of 0.5 mVs−1 the potential separation of the OP-LiFePO4 sample (about 250 mV) is much smaller than that of S-LiFePO4 (about 443 mV). More importantly, the initial discharge capacities at 0.1 and 1.0 C for the OP-LiFePO4/MWNTs are 160.58 and 116.71 mAhg−1, higher than that of S-LiFePO4/C (151.29 and 95.69 mAhg−1 at 0.1 and 1.0 C).