Full gradient compensation of LiNO3 in the suspension electrolyte for lithium metal batteries

Abstract

Uncontrolled side reactions between lithium metal and organic electrolytes seriously deteriorates the stability of corresponding battery due to the non-uniform Li⁺ deposition. Using lithium nitrate (LiNO₃) as an additive can adjust the components in solid-electrolyte-interphase (SEI) for optimizing of lithium metal interface. However, the low solubility and rapid consumption of LiNO₃ in ester-based electrolytes limit its further application. Herein, a kind of suspension electrolyte containing micron-sized LiNO₃ particles is reported to realize a full gradient compensation against the consumption of NO₃⁻. Benefiting from the uniformly dispersion of LiNO₃ particles, a SEI layer containing even-distributed Li₃N and LiN_xO_y with high content is constructed that promotes the rapid and uniform plating of Li⁺. Consequently, the Li/Cu batteries present a polarization of only 15–20 mV, and exhibit a consistent performance for 230 cycles with the CE of 98.1%, which is 4 times than that of conventional carbonate electrolytes. In addition, the cycling life of the assembled Li/NCM811 batteries can be extended to 260 cycles with a high capacity retention of 82.4 %.