Part of Cell capacity.

When cell is rested after non-stop cycling, its capacity can recover for multiple reasons:

The authors of [1] suggest that Frequent rest recovers capacity and prolongs a cell's life because Lithium plating is a self-reinforcing process, therefore, preventing it early leads to compounding benefits.

The reverse process is Cell capacity fade.

References

[1] Investigation of capacity recovery effects due to rest periods during high current cyclic ageing tests in Li-ion cells and their influence on lifetime

[2] Evaluation of cyclic aging tests of prismatic automotive LiNiMnCoO2-Graphite cells considering influence of homogeneity and anode overhang