Measurements of ageing and thermal conductivity in a secondary NMC-hard carbon Li-ion battery and the impact on internal temperature profiles

摘要: Abstract The ageing of 75 commercial Li-ion secondary batteries with LiNiMnCoO 2 | hard carbon chemistry was studied up to 4 years. nominal capacity 17.5 Ah. were cycled at different current rates and between states charge. Shelf studies carried out temperatures temperature varied from 18-55 °C. specific ohmic resistance obtained as a function state health, temperature, time. We found that the cell tolerated less cycles higher temperatures. loss also increased for storage temperatures, in predictable manner. observed charge moment very important discharge capacity. Thermal conductivities pristine aged electrodes measured presence absence electrolyte solvent under compaction pressures. thermal conductivity range 0.14–0.41 WK −1 m dry electrode active material 0.52–0.73 WK solvent-soaked material. materials did not change significantly ageing, but strong correlation seen remaining battery increasing resistance. To assess impact these changes, results used one-dimensional model compute internal temperature. Temperature profiles computed discharging rate (2C - 10C) time (0 years). showed can raise by factor about 2.5 during health 100 % 58