Robust Solid‐Electrolyte Interphase Enables Near‐Theoretical Capacity of Graphite Battery Anode at 0.2 C in Propylene Carbonate‐Based Electrolyte
Jisoo Han, Gyeong Jun Chung, Seung‐Wan Song
Abstract
Abstract The formation of a robust solid‐electrolyte interphase (SEI) layer at the surface of a graphite anode by electrolyte control is a key technology for high‐performance lithium‐ion batteries. Although propylene carbonate (PC) offers a lower melting point than ethylene carbonate, its combination with the graphite anode without additive is a worse choice, owing to co‐intercalation of PC and Li + ion into graphite, exfoliation of graphene sheets, and death of the battery. This study reports a graphite anode with an unprecedentedly high initial coulombic efficiency of 94 %, close to theoretical capacity, and excellent capacity retention of 99 % after 100 cycles in a PC‐based electrolyte system, even at an unusually high rate of 0.2 C, which is generally attainable only at a very low rate of below 0.05 C in commercial electrolyte. The SEI stabilization for a graphite anode in PC‐based electrolyte provides a new avenue for high‐energy and high‐performance batteries in widened range of working temperatures. A strong correlation between anode‐electrolyte interfacial stabilization and highly reversible cycling performance is clearly demonstrated.