How does external pressure affect battery life?

Studies have shown that the introduction of external pressure can effectively reduce the “solid-solid” contact resistance and prolong the cycle life of the battery. At the same time, the application of external pressure on the electrode materials has dramatic multiple interdisciplinary consequences.

Why is initial pressure important in a battery?

Owing to the physical constraints of their external casings and the fact that they continuously undergo volume changes during charge-discharge cycling, batteries are subjected to changes in pressure. Setting the optimal initial pressure is important because it could affect the performance and cycle life of batteries [9-13].

Why is external pressure important for lithium-ion batteries?

The expansion and contraction of the anode and the irreversible growth of the SEI film during charge-discharge cycling result in pressure changes on fixed batteries. External pressure could improve the contact efficiency of the electrode material, and proper external pressure is beneficial for the cycle life of lithium-ion batteries.

Does pressure increase affect battery life?

SEM and ICA results show that this is caused by the damage of the active material inside the battery, indicating that a relatively large external pressure is detrimental to battery life. In order to reduce the negative effects of pressure increase on constrained battery, the comparative experiment was set.

How does compression affect a battery's mechanical pressure?

However, the constraint became rigid when the compression exceeded 0.2 mm. Compared to the k values of the batteries in groups (a) and (b), that of the batteries in group (c) was smaller, and the expansion and contraction of the springs during the charge-discharge process stabilized the mechanical pressure on the batteries.

Why does battery pressure increase during later charge-discharge cycles?

Although the initial pressure on the battery was relatively low, the battery was subjected to relatively high pressure during later charge-discharge cycles owing to battery expansion, which resulted from the irreversible accumulation of stress, and the pressure more than doubled during later charge-discharge cycles compared to the initial pressure.