National Research Council of Canada. Energy, Mining and Environment
Carbon; Cathodes; Characterization; Electric batteries; Electrodes; Ethylene; Glucose; Liquids; Lithium; Nanoparticles; Nanorods; Particle size; Scanning electron microscopy; Secondary batteries; Transmission electron microscopy; X ray diffraction; Cath-ode materials; Crystalline structure; Electrochemical test; High crystallinity; Initial discharge capacities; Liquid-phase method; Lithium manganese phosphates; TEM characterization; Lithium-ion batteries
The cathode material of the LiMnPO4/C composite for lithium-ion batteries is successfully synthesized via a one-step glucose-assisted liquid-phase method in ethylene glycol (EG). The crystalline structure, morphology, micro-structure and particle size are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). XRD results show that the pure phase of LiMnPO4 with high crystallinity can directly be prepared in the liquid-phase assisted by glucose. SEM measurements confirm the uniform-sized nanorods of the LiMnPO4 morphology with a width of 20-50 nm and a length of 50-80 nm. TEM characterization reveals that the surface of the obtained LiMnPO4 nanorods is coated with a homogeneous carbon layer after a short heat treatment at a high temperature in the presence of glucose. This can be explained by the fact that the glycol glucoside generated during the refluxing of EG with glucose can effectively inhibit the growth and agglomeration of particles. Results of electrochemical tests show that the prepared LiMnPO4/C nanorods exhibit not only a high initial discharge capacity of 155.3 mAh g-1 but also a good cycling stability, which retains 94% of the initial capacity over 100 cycles at 0.05 C.
Electrochimica Acta189 (18 December 2015): 205–214.