Robust Solid-Electrolyte Interphase Enables Near-Theoretical Capacity of Graphite Battery Anode at 0.2 C in Propylene Carbonate-Based Electrolyte.

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.