Abstract
This paper discusses the critical importance of reducing the electrolyte wetting, formation, and aging times associated with lithium-ion battery (LIB) manufacturing. These steps are essential for ensuring high quality LIBs with uniform capacity, safety, and long cycle life, but they add great expense to the manufacturing cost, as wetting and formation may take 3-7 days and aging may take up to additional two weeks. These steps account for a considerable portion of production plant capital expenses and can take up to 25% of the floor space. Wetting and formation are also necessary for building the anode solid electrolyte interface (SEI) and cathode electrolyte interface (CEI). Aging is necessary for determining whether leakage currents are too high before the rated capacity is assigned to a LIB. The SEI and CEI formation process, the effect of formation protocols themselves, and the importance of electrolyte imbibition into the electrode and electrolyte pores are considered in the context of the overall industrial challenges associated with these three “end of cell production” steps. The original data presented here is discussed in a broader context of lowering the production and capital costs of manufacturing LIBs, and an outlook is given on the implementation of these technologies by U.S. battery manufacturers. Other technologies, such as addition of surface coatings of the active material powders, are considered as possible solutions to further reduce or even eliminate wetting, formation, and aging altogether.
