چكيده به لاتين
Lithium-ion batteries are one of the most used batteries and cathodes are an important part of them. Nickel-rich Layered cathodes, due to their high capacity, are of interest today. Methods of synthesis these materials include sol-gel method, combustion synthesis, solid state methods and co-precipitation. Due to the high volume production of the material and the industriality of the co-precipitation method as well as the good control of the synthesis conditions in this method, the co-precipitation method was used in this study to produce cathode material. Conditions governing the synthesis process, as well as the calcination temperature of the synthesized metal hydroxides, are among those that will have a significant impact on the performance of the cathode material produced. Therefore, in this study, factors such as concentration of metal salt solution in the range of 0.5 to 2 M, pH of reaction in the range of 9 to 10.4, stirring speed of reactants in the reactor in the range of t200 to 800 rpm, rate of injection of metal salt solution The inside of the reactor was tested in the range of 35 to 210 ml / h, Concentration of ammonia solution in the range of 2.5 to 10 M . The calcination temperature was also studied in the range of 650 to 850 ° C. Also in this project The two sources of aluminum used for synthesis of the NCA cathode (Sodium aluminate and aluminum sulfate) were compared. The influence of these factors on the morphology of primary and secondary particles was investigated by FESEM microscopic images. Dijimizer software was used to measure the primary and secondary particles. ICP and EDS were used to evaluate the stoichiometry of the synthesized cathode materials. XRD was used to investigate the phases and crystalline structure of the synthesized material. TGA was used to determine the temperature change phase of metal hydroxides during the calcination process. Among the synthesized samples, according to the powder density and the resulting particle morphology, the injection rate of 35 ml / h, salt concentration of 2 molar , stirring speed of 500 rpm, pH of reaction of 9.7 and Concentration of ammonia solution of 5 M were declared as the appropriate conditions. Also, according to the X-ray diffraction pattern and lattice parameters, calcination temperatur of 750 was declared as suitable temperatur. Also Sodium aluminate As optimal aluminum source for synthesis of the NCA cathode was identified. Finally, the effect of parameters of synthesis on the electrochemical performance of lithium ion batteries by impedance test, discharge-charge capacity were evaluated. and cycles
