Surface Phosphatization for a Sawdust‐Derived Carbon Catalyst as Kinetics Promoter and Corrosion Preventer in Lithium–Oxygen Batteries
Huancheng Huang, Changjing Cheng, Guoliang Zhang, Liang Guo, Gaoyang Li, Min Pan, Feng Dang, Xianmin Mai
Abstract
Abstract Strong oxidant intermediates and the formation of byproducts during the discharge/charge process are the main challenges in the degradation of lithium–oxygen batteries (LOBs). A facile approach to maintain the stability of the cathode catalyst and avoid the formation of byproducts is essential for the development of LOBs. Here, a sawdust‐derived carbon catalyst is fabricated and subjected to surface phosphatization to suppress corrosion between carbon and electrolyte/products. This prevents the formation of byproducts from parasitic reactions and boosts the reaction kinetics of the carbon catalyst in LOBs. The doped P atoms will prior to substitute an N atom in pyrrolic‐N sites to form graphitic PN sites, instead of the graphitic PC sites. Experimental and density functional theory calculations reveal that the graphitic PN sites can function as a reaction kinetics promoter for the formation/decomposition of discharge products. Moreover, the graphitic PN sites can also prevent the formation of byproduct Li 2 CO 3 from the corrosion of the carbon catalyst, despite its poor catalytic capability in LOBs. As a result, the sawdust‐derived P‐doped catalyst exhibits an enhanced specific capacity of ≈20 000 mAh g –1 and long cycle stability of 226 and 160 cycles at 200 and 500 mA g –1 , respectively.