Preparation And Modiffication Of LiFePO₄/C By Hydrothermal Method

As a new type secondary battery, lithium battery has been paid much attention.As a new type cathode materia l of secondary battery, LiFePO4 has been paid muchattention for its lower price, environmentally friend ly, high energy density, stabilityand safety. And LiFePO4 has been considered as the most promising materia l.Olivine LiFePO4/C cathode materia l was synthesized by hydrotherma l method inN2 atmosphere. The crysta l structure was characterized by XRD, SEM and TEM. Thecycling performa nce was characterized by electrochemica l performa nce testing. Inthis paper, gelatin and glucose were introduced as carbon sources, and the coatedeffect of different carbon sources were compared. The results demonstrated that thesample with gelatin shows more perfect micro-morp hology and more excellent carboncoating effect. The LiFePO4 carbon-doped by both gelatin and glucose displa ys themos t satisfying electrochemica l performa nce. The initia l discharge capacity of thesample was achieved to 80mAh·g-1 at 0.1C.In this paper,studies on doping modification of LiFePO4 were carried out. Bothanion (Ni2+, Ti4+) and cation (F-) were introduced into the LiFePO4. LiFePO4 solidsolution were obtained in hydrotherma l process. The results demonstrated that ionshad little influence on the micro-morphology. However, the doping modificationimproved the electrochemica l performa nce, especia lly discharge behaviors aftermultiple cycles.