Improving Polysulfides Adsorption and Redox Kinetics by the Co₄N Nanoparticle/N‐Doped Carbon Composites for Lithium‐Sulfur Batteries

Abstract

Improved conductivity and suppressed dissolution of lithium polysulfides is highly desirable for high‐performance lithium‐sulfur (Li‐S) batteries. Herein, by a facile solvent method followed by nitridation with NH3, a 2D nitrogen‐doped carbon structure is designed with homogeneously embedded Co4N nanoparticles derived from metal organic framework (MOF), grown on the carbon cloth (MOF‐Co4N). Experimental results and theoretical simulations reveal that Co4N nanoparticles act as strong chemical adsorption hosts and catalysts that not only improve the cycling performance of Li‐S batteries via chemical bonding to trap polysulfides but also improve the rate performance through accelerating the conversion reactions by decreasing the polarization of the electrode. In addition, the high conductive nitrogen‐doped carbon matrix ensures fast charge transfer, while the 2D structure offers increased pathways to facilitate ion diffusion. Under the current density of 0.1C, 0.5C, and 3C, MOF‐Co4N delivers reversible specific capacities of 1425, 1049, and 729 mAh g−1, respectively, and retains 82.5% capacity after 400 cycles at 1C, as compared to the sample without Co4N (MOF‐C) values of 61.3% (200 cycles). The improved cell performance corroborates the validity of the multifunctional design of MOF‐Co4N, which is expected to be a potentially promising cathode host for Li‐S batteries.

Free-standing N-doped hollow carbon fibers as high-performance anode for potassium ion batteries

“…Third, the amorphous structure of carbon contains many two-dimensional (2D) graphite layer or 3D graphitic micro-crystallites. There are many irregular bonds or functional groups on the edges of the crystallites, which will provide more active sits for potassium ion adsorption [18,[50][51][52]. So, the amorphous structure of NHCF@NCC is beneficial to the potassium ion adsorption.…”

“…There is a large cathodic peak at 0.425 V at the first cycle, which can be attributed to the formation of the solid electrolyte interface (SEI) layer and the decomposition of electrolyte (including salts and solvents). In the next CV curves, there are cathodic peak at 0.69 V and anodic peak at 1.49 V, in which the small redox peaks at 0.69/1.49 V show a sign of pseudocapacitance [49,50,57]. From the third cycle, the shape of the CV curve does not change significantly.…”

Catalyzing the polysulfide conversion for promoting lithium sulfur battery performances: A review

“…NbN@N-Graphene hybrids [105] show excellent catalytic behaviors and enhanced redox reaction kinetics due to interrelationship of Nb cation with LiPSs via Nb-S chemical bonding and promoting conversion of LiPSs into insoluble Li 2 S. Besides, the highly conductive NbN and N-Graphene provide rapid electron transport pathway, which feeds the nearly-insulating S or Li 2 S during battery operation. Co 4 N nanoparticles also shows the strong chemical adsorption ability and catalytic activity via chemical bonding to trap polysulfides and accelerate the conversion reactions by decreasing the polarization of the electrode [106].…”

Metal‐Organic Framework‐Derived Fe‐Doped Co1.11Te2 Embedded in Nitrogen‐Doped Carbon Nanotube for Water Splitting

“…All calculations were conducted by Vienna ab initio simulation package (VASP) [37][38] with Perdew-Burke-Ernzerhof (PBE) [41] generalized gradient approximation (GGA) density functional theory (DFT). A 500 eV cut-off for the plane-wave basis set was adopted in all calculations, and a (2 × 3 × 1) k-point grid was applied.…”