Phase‐inversion constructed MoC@NC microreactor with optimized pyridinic N p‐band center for high‐performance Li–S batteries
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
Abstract Nitrogen‐doped carbon (NC) is widely employed as a conductive matrix in Li‐S batteries, yet its intrinsic catalytic contribution is often overlooked when combined with metal compounds. Herein, we propose a hierarchical microreactor architecture that integrates conductive and catalytic functions through an intimately coupled MoC@NC interface. Density functional theory calculations demonstrate that coupling NC with MoC induces pronounced electron redistribution of N atoms, with pyridinic N exhibiting the strongest charge transfer from MoC, making the p‐band center closest to the Fermi level, thereby endowing superior LiPSs adsorption activity. Guided by this insight, a phase‐inversion strategy is employed using pyridinic‐N‐rich polyacrylonitrile (PAN) and MoOprecursors to construct a cross‐linked MoO@PAN network, which is subsequently transformed into MoC@NC microreactors after carbonization. In this structure, MoC nanowires are uniformly confined within pyridinic‐N‐rich carbon shells, forming a zero‐distance conductive–catalytic interface that enables efficient electron transfer from MoC to NC. This integrated microreactor provides continuous electron pathways, abundant catalytic sites, and unobstructed ion transport, effectively avoiding pore blockage commonly encountered in conventional composite cathodes. Consequently, the MoC@NC cathode exhibits high cycling stability over 1000 cycles at 2.0 C with a low decay rate of 0.052% per cycle. Even at 4.0 C, it retains 79
Abstract
Abstract Nitrogen‐doped carbon (NC) is widely employed as a conductive matrix in Li‐S batteries, yet its intrinsic catalytic contribution is often overlooked when combined with metal compounds. Herein, we propose a hierarchical microreactor architecture that integrates conductive and catalytic functions through an intimately coupled MoC@NC interface. Density functional theory calculations demonstrate that coupling NC with MoC induces pronounced electron redistribution of N atoms, with pyridinic N exhibiting the strongest charge transfer from MoC, making the p‐band center closest to the Fermi level, thereby endowing superior LiPSs adsorption activity. Guided by this insight, a phase‐inversion strategy is employed using pyridinic‐N‐rich polyacrylonitrile (PAN) and MoOprecursors to construct a cross‐linked MoO@PAN network, which is subsequently transformed into MoC@NC microreactors after carbonization. In this structure, MoC nanowires are uniformly confined within pyridinic‐N‐rich carbon shells, forming a zero‐distance conductive–catalytic interface that enables efficient electron transfer from MoC to NC. This integrated microreactor provides continuous electron pathways, abundant catalytic sites, and unobstructed ion transport, effectively avoiding pore blockage commonly encountered in conventional composite cathodes. Consequently, the MoC@NC cathode exhibits high cycling stability over 1000 cycles at 2.0 C with a low decay rate of 0.052% per cycle. Even at 4.0 C, it retains 790.6 mAh gfor over 400 cycles with only 0.027% fading per cycle. A phase‐inversion constructed MoC@NC microreactor activates the intrinsic catalysis of nitrogen‐doped carbon via interfacial electron redistribution. Strong charge transfer to pyridinic N optimizes the p‐band center, enabling efficient lithium polysulfide adsorption, fast redox kinetics, and long‐term stable, high‐rate Li–S battery performance. graphical