Surface Phosphatization for a Sawdust‐Derived Carbon Catalyst as Kinetics Promoter and Corrosion Preventer in Lithium–Oxygen Batteries. (15th January 2022)

• Record Type: Journal Article
• Authors: Huang, Huancheng; Cheng, Changjing; Zhang, Guoliang; Guo, Liang; Li, Gaoyang; Pan, Min; Dang, Feng; Mai, Xianmin
• Is Part Of: Advanced functional materials. Volume 32:Number 17(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-15
• Subjects: cathode catalysts -- corrosion preventer -- DFT calculations -- lithium–oxygen batteries -- P‐doped; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202111546
• Languages: English
• ISSNs: 1616-301X

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 PN sites, instead of the graphitic PC sites. Experimental and density functional theory calculations reveal that the graphitic PN sites can function as a reaction kinetics promoter for the formation/decomposition of discharge products. Moreover, the graphitic PN sites can also prevent the formation of byproduct Li2 CO3 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. Abstract : Surface phosphatization can not only serve as kinetics promoters that induce the initial nucleation and growth of the discharge product (Li2− x O2 ) but also suppress the corrosive issue between carbon active site and electrolyte/products to avoid side products formation from parasitic reactions in lithium–oxygen batteries.