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.
The development of durable and highly efficient visible-light-driven photocatalysts is essential for the photocatalytic ozonation process towards degrading organic pollutants. This study presents CN-MA, a novel photocatalyst synthesized by grafting carbon nitride (CN) with single-atom Mn and 2-hydroxy-4,6-dimethylpyrimidine (HDMP) via one-step thermal polymerization. Experimental characterization and theoretical calculation results reveal that incorporating single-atom Mn and HDMP into CN alters the charge density distribution on the heptazine rings. This modification enhances the absorption of visible light and reduces exciton binding energy, leading to improved separation and migration of photogenerated charge carriers. Moreover, the single-atom Mn provides abundant active sites for O 3 adsorption and activation, which increases the utilization of photogenerated electrons to produce highly reactive oxidative species. Consequently, CN-MA exhibits superior photocatalytic ozonation activity, achieving 94% mineralization of phenol within 60 min and maintaining excellent stability over multiple cycles. The research also proposes a plausible reaction mechanism based on free-radical trapping experiments and steady-state concentration experiments using molecular probes. This strategy advances the development of molecular-engineered catalysts co-modified with single metal atoms, thereby enhancing the photocatalytic ozonation process for the degradation of organic pollutants.
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