Study On The Effects Of Lithium Manganese And Electrolyte In LMO/LTO Battery

Li4Ti5O12(LTO) battery has excellent the advantages of long cycle life, high rate discharge and fast charging ability. It shows a good application prospect in electric vehicles and large-scale energy storage. At present, many researcher ’s work are mostly focused on the modification of Li4Ti5O12, rather than the research and development of Li4Ti5O12 battery system. Therefore, in order to achieve the industrialization application of Li4Ti5O12 battery as soon as possible, it must be develop the excellent performance and high security of Li4Ti5O12 battery, this needs to find battery materials that match with Li4Ti5O12 materials and the optimization production technology of Li4Ti5O12 battery. In this thesis, we first characterized and test electrochemical performance of the lithium manganese(LMO)cathode materials, and then studied the effects of different lithium manganese and electrolyte to flexible package and laminated LMO/LTO battery performance.Three kinds of lithium manganese materials are investigated by X-ray diffraction(XRD) and Scanning electron microscope (SEM). The material LMO-1 and LMO-2 particle size are small, but there is agglomeration, LMO-3 particle size is larger, but the distribution is uniform. With lithium manganese and lithium assembled into half cell,to explore the electrochemical properties of various materials of lithium manganese. Comparison of three half-cell rate performance data and found that LMO-2/Li shows the best rate charge-discharge performance. Charge with 0.5 C, it shows capacity performance with rate capacity of 94.8 mAh·g-1、85.1 mAh·g-1、61.1 mAh·g-1 at 0.5 C、1C、2C,respectively;Discharge with 0.5 C, it shows capacity performance with rate capacity of 98.9 mAh·g-1、88.8 mAh·g-1、64.5 mAh·g-1 at 0.5 C、1C、2C,respectively. When charge-discharge cycle,LMO-3/Li delivered a highest initial discharge specific capacity of 110.8mAh/g at o.5 C,but the cycle stability is worse than LMO-1/Li and LMO-2/Li, LMO-2/Li showed capacity retention of 77.1 % after 100 cycles at 0.5 C, higher than 73.5% of LMO-3/Li.LMO/LTO flexible package battery as carrier, to research the impact of the materials used in battery on its performance. In the aspect of lithium manganese cathode materials, it was found that LMO-2/LTO exhibited best rate discharge performance, while LMO-3/LTO showed the most stable of cycle performance. In the aspect of electrolytes, select LMO-3/LTO battery as test object, three kinds of electrolyte have the same effect on battery polarization’s change, and E2 is better than E1 and E3 for the performance of rate diacharge and rate charge. When the cycle under room temperature conditions,three kinds of electrolyte have the same effect on battery cycling stability, but E2 have the maximum discharge capacity. However, at -25 ℃, the E2 electrolyte of battery discharge capacity is only 71.3% of the room temperature.The E2 electrolyte of battery cycling process at high temperature has been accompanied by gas production, and the gas play a direct impact on battery performance.After exhaust, battery discharge platform rose, discharge capacity increased, and the more frequently the exhaust, the higher the overall capacity of battery.