A Lithium Dendrite Inhibitor in Graphite Anodes Enabling Fast-Charging and Low-Temperature Lithium-Ion Pouch Cells.

Abstract

Under harsh conditions, such as high-rate and low-temperature charging, part of Li ions cannot intercalate into the graphite (Gr) particles and will form dendrite-like Li plating, causing capacity fading and serious safety hazards in commercial lithium-ion batteries (LIBs). Herein, instead of eliminating the Li plating, a Li plating regulation strategy that transforms dead Li plating into reversible active Li plating is proposed by using a lithium dendrite inhibitor to realize safe and long-lifespan LIBs. Remarkably, only 1 wt.% single-atom manganese (SAMn) in the Gr anode (Gr-SAMn) is sufficient to achieve a significant improvement, thus both the volumetric and mass-energy density remain roughly unaffected. The amount of dead Li on the Gr anode can be reduced by 90%, thereby enabling much-improved pouch cell performance at high rates and low temperatures. The capacity retention of the Gr-SAMn||NCM811 pouch cell is 86.2% (23.0% higher than that of the pristine Gr||NCM811 pouch) for 1500 cycles at 2 C, and the cell can even be cycled at 5C charge. Even cycling at -20 °C, the average coulombic efficiency (CE) can be improved from 97.95% to 99.94% by using SAMn additive. Hence, this promising strategy provides a novel alternative to solve the Li plating issue.