Effect of Pre-Compression Force on Performance of NMC Prismatic Battery

The battery industry is heavily growing and the number of batteries being produced has risen since the growth of electric vehicle (EV) sector.A key challenge faced is prolonging a battery's life while having it perform at its max.Compressing cells can help a battery perform better by reducing the direct current internal resistance (DCIR).But so far testing has mainly been performed on coin and pouch cells, with very little research on prismatic cells.Focusing on this, two high Nickel content NMC prismatic cells were tested to see if and how their performance depends on compression forces.First, forces from 1 kN to max 5.5 kN were applied in increasing order.Then they were applied in decreasing order, ending the test with the cells in free-standing.The results had DCIR values increasing with increasing levels of force, mainly at extreme SOC values.While decreasing the force applied, the DCIR values did not increase or drop but rather stayed at the same level.At the lower extreme SOC, discharge DCIR values grew by 3.2% and 3.5% normalised units between 1 kN and 5.5 kN.The plausible reasons for rising DCIR values have been discussed.