Phosphorus‐Mediated Local Charge Distribution of N‐Configuration Adsorption Sites with Enhanced Zincophilicity and Hydrophilicity for High‐Energy‐Density Zn‐Ion Hybrid Supercapacitors
Wen Lu, Bin‐Bin Xie, Chen Yang, Cong Tian, Lei Yan, Jiqiang Ning, Sha Li, Yijun Zhong, Yong Hu
Abstract
Abstract Tailor‐made carbonaceous‐based cathodes with zincophilicity and hydrophilicity are highly desirable for Zn‐ion storage applications, but it remains a great challenge to achieve both advantages in the synthesis. In this work, a template electrospinning strategy is developed to synthesize nitrogen and phosphorous co‐doped hollow porous carbon nanofibers (N, P‐HPCNFs), which deliver a high capacity of 230.7 mAh g −1 at 0.2 A g −1 , superior rate capability of 131.0 mAh g −1 at 20 A g −1 , and a maximum energy density of 196.10 Wh kg −1 at the power density of 155.53 W kg −1 . Density functional theory calculations (DFT) reveal that the introduced P dopants regulate the distribution of local charge density of carbon materials and therefore facilitate the adsorption of Zn ions due to the increased electronegativity of pyridinic‐N. Ab initio molecular dynamics (AIMD) simulations indicate that the doped P species induce a series of polar sites and create a hydrophilic microenvironment, which decreases the impedance between the electrode and the electrolyte and therefore accelerates the reaction kinetics. The marriage of ex situ/in situ experimental analyses and theoretical simulations uncovers the origin of the enhanced zincophilicity and hydrophilicity of N, P‐HPCNFs for energy storage, which accounts for the faster ion migration and electrochemical processes.