Molecule/Ion Anchoring Interphase Achieving 4.8 V Fast-Cycling Lithium Metal Batteries

Abstract

Lithium (Li) metal batteries with high-voltage nickel-rich layered cathodes are some of the most promising candidates for next-generation high-energy-density batteries. However, their practical application is hindered by the structural degradation and uncontrollable dendrite growth at high cutoff voltage. Here, we present a precise molecule/ion anchoring strategy to achieve stable cycling performance of a Li metal battery under an ultrahigh cutoff voltage of 4.8 V at 5 C by exploring an electrolyte additive. The additive facilitates the formation of a thin interphase layer composed of B_xO_y, LiF, and Li_xPO_yF_z species on both cathodes and anodes. The cathode interphase could inhibit the gas release and transition metal ion dissolution through chelation reaction and Lewis base-acid interaction. Additionally, the anode interphase enables uniform Li deposition, resulting in a high Coulombic efficiency (CE) of 99.34%. Therefore, the Li||NCM622 cell can maintain an 80% capacity retention after 300 cycles at 4.8 V.