Glossary
Initial capacity loss
Capacity that is not available for reversible cycling after the first charge and discharge steps.
During the first charge and discharge of a lithium-ion cell, part of the available lithium is consumed, for example in the formation of interface layers on the anode. The capacity linked to that consumed lithium is no longer available for reversible cycling, which is commonly described as initial capacity loss or first-cycle loss.
The size of this effect depends on the active material, the electrode design, the binder and electrolyte system and the formation conditions. Materials with a high specific capacity and large volume change, such as silicon-containing anodes, are often discussed in this context, but the effect is not limited to them.
Prelithiation is one of the approaches evaluated to address initial capacity loss. How much can be addressed in a specific system is a development question and depends on materials and process conditions.