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

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 BxOy, LiF, and LixPOyFz 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.