Dual-Functional Atomic Zinc Decorated Hollow Carbon Nanoreactors for Kinetically Accelerated Polysulfides Conversion and Dendrite Free Lithium Sulfur Batteries

摘要

The lithium sulfur (Li-S) battery is a preferential option for next-generation energy storage technologies, but the lithium polysulfide shuttling, sluggish redox kinetics, and uncontrollable lithium dendrite growth hamper its commercial viability. Herein, well-dispersed single atom Zn-decorated hollow carbon spheres (Zn-1-HNC) are developed as dual-functional nanoreactors for polysulfides-suppressed sulfur cathodes (Zn-1-HNC-S) and dendrite-free lithium anodes (Zn-1-HNC-Li) simultaneously for high-capacity, high-rate, and long-cycling Li-S batteries with fast redox kinetics. Benefiting from its excellent electronic conductivity, high surface area (370 m(2)g(-1)), highly-effective active sites and protective carbon shell, the resultant nanoreactor possesses strong physical confinement, chemical anchoring, and exceptional electrocatalysis for polysulfides. Meanwhile, the nanoreactor with excellent lithiophilic ability realizes uniform and dendrite-free lithium deposition. Integrating all these advantages, the assembled full battery (Zn-1-HNC-S||Zn-1-HNC-Li) delivers remarkable electrochemical properties including long cycle stability with an ultralow capacity fading rate of 0.015% per cycle over 700 cycles and superb rate performance of 989 mAh g(-1)at 10 C. Moreover, a high areal capacity of 8.7 mAh cm(-2)with high S loading of 7.8 mg cm(-2)at low E/S ratio (6.4 mu L mg(-1)) is achieved. This work provides significant insight of structure and surface catalytic chemistry regulation for promoting the actual application of Li-S batteries.