Tailoring electrode-electrolyte interphases to enable the cycling stability of lithium metal batteries with LiNi0.8Co0.1Mn0.1O2 cathode

Abstract

Rechargeable lithium metal batteries (LMBs) coupling with Ni-rich cathodes are promising high-energy-density electrochemical energy storage devices. However, the growth of Li dendrites and structural degradation of Ni-rich materials, associated with the erratic electrode-electrolyte interphase (EEI) and corrosion of harmful acidic species from the hydrolysis of LiPF6, seriously deteriorate the cycling performance of LMBs with Ni-rich cathodes. Herein, glutaric anhydride (GA) as a multifunctional electrolyte additive is proposed to achieve satisfactory lifespan of LMBs by in situ constructing LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode/Li anode-electrolyte interphases (CEI/AEI), and scavenging corrosive acidic species. The GA-derived CEI/AEI layers are rich in CO species, which can strongly coordinate with the Li anode and delithiated Ni-rich cathode surface. Thus, parasitic reactions of the electrolyte on the aggressive surface of the Ni-rich cathode and Li anode are notably reduced. Furthermore, the problems such as the inner microcrack evolution of NCM811 particles, the growth of Li dendrites and the corrosion of acidic species are well addressed. Consequently, the capacity retention of Li/NCM811 cell is increased from 59.4% to 90.7% after 300 cycles at 1C in the presence of GA, and the Li/Li symmetrical cell with GA exhibits the super-stable cyclic performance of 1400 h at 0.2 mA cm−2.