On the gassing behavior of lithium-ion batteries with NCM523 cathodes

Gas evolution has a profound effect on the functioning of state-of-the-art lithium-ion batteries. On one hand, it is the natural concomitant of solid electrolyte interphase (SEI) formation on the anode (reduction of electrolyte components). On the other hand, because of the demand for high terminal voltages, it is also the consequence of electrolyte and/or cathode material oxidation. Overall, gassing happens on the expense of Coulombic efficiency and additionally raises safety issues. Herein, the gassing behavior of one of the most important commercialized cathode materials, namely Ni-rich Li 1 + x Ni 0.5 Co 0.2 Mn 0.3 O 2 (NCM523 with 0.01