The need for pre-lithiation has become more important due to the commercialization of anodes containing silicon for high energy density batteries. When Si/Graphite mixtures are used, there can be 10-20% or higher active lithium loss on the first charge depending on the amount of Si used. Pre-lithiation can introduce sacrificial lithium into a lithium ion cell which will off-set the irreversible lithium loss. There are many proposed pre-lithiation techniques such as roll-to-roll electrochemical baths, sacrificial salts, vacuum deposition and lithium sputtering. None of these pre-lithiation methods have been scaled beyond the laboratory or pilot scale due to safety, cost, manufacturing inefficiencies or cell performance issues. Currently, the pre-lithiation method that has shown the most promise is the addition of lithium metal to the prefabricated anode. Because of its high capacity, lithium metal causes a negligible increase in cell mass and volume. In comparison, when sacrificial salts are used, the energy density can decrease due inactive phases remaining after lithium extraction.
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