Insight into the Effect of LiNO3 Additive in High‐Voltage NCA Cathode with a Cylindrical 18650 Lithium-Metal Battery

Abstract

Lithium metal is an attractive anode material for rechargeable batteries due to its extremely high theoretical specific capacity (3860 mA h g−1) and low density (0.59 g cm−3). Unfortunately, lithium metal itself faces huge problems including inhomogeneous lithium deposition, infinite volume expansion, increased polarization, and dendrite formation. To overcome these drawbacks, many researchers have employed LiNO3 additive in the ether-based electrolyte to modify the properties of the solid electrolyte interface (SEI) film formed on the lithium metal surface. The LiNO3 can improve an ionically conductive, dense, and stable SEI formation through Li stripping and plating. However, LiNO3 has low solubility in carbonate based. Thus, LiNO3 was applied as an additive in carbonate electrolyte using CuF2 as a dissolution promoter. Herein, we demonstrate carbonate electrolyte system using LiNO3 and CuF2 with different ratios in high‐voltage Ni‐rich cathode with a cylindrical shape (18650). To achieve fundamental understanding of the effect of electrolyte additive molecules on the SEI formation at the lithium anode, reactive molecular dynamic simulation (Reaxff) has been used to investigate the mechanism and property of the SEI layer on the lithium anode.