In this paper we evaluate what is the impact of the temperature, pressure and C-rate on the performance of a pouch Li-ion cell. With state of the art system it is not possible to evaluate the impact of each of the mentioned parameters. As example, in a climatic chamber it is not possible to keep the Li-ion cell in an isothermal condition, hence, the impact of the temperature on the electrical performance cannot be fully evaluated. This is why we developed a novel testbench to achieve better control of mechanical, thermal and electrical parameters of the Li-ion cell. With our novel testbench we could evalute the impact of each single parameter on the electrical performance: pressure, temperature and C-rate.

The results of the study confirm what has been found in the literature: an increase in pressure leads to a decrease in performance, while an increase in temperature leads to an increase in performance. However, the extent to which the pressure impacts performance is determined by the temperature and the applied electrical discharge rate. At 5 °C and 0.5 C, an increase in pressure from 0.2 MPa to 1.2 MPa results in a 5.84% decrease in discharged capacity. At 45 °C the discharge capacity decreases by 2.17%. Regarding the impact of the temperature, at discharge rate of 0.5 C, with an applied pressure of 0.2 MPa, an increase in temperature from 25 °C to 45 °C results in an increase of 4.27% in discharged capacity. The impact on performance varies significantly at different C-rates. Under the same pressure (0.2 MPa) and temperature variation (from 25 °C to 45 °C), increasing the electrical discharge rate to 1.5 C results in a 43.04% increase in discharged capacity. The interplay between temperature, pressure and C-rate has a significant, non-linear impact on performance.