MOFs-derived integrated flower shaped porous carbon anchored with core-shell Ni-NiO nanoparticles as efficient multifunctional electrode for Li–S batteries

Designing electrodes with structures suitable for storing and fixing sulfur to overcome the inherent shortcomings of lithium-sulfur (Li–S) batteries is an effective approach to achieving commercial application. Indeed, multifunctional electrodes constructed with sulfur immobilization substrate and efficient catalyst has dramatically improved the utilization of sulfur. However, structurally designing the substrate and achieving uniform dispersion of catalytic remain huge challenges. In this paper, a metal-organic frameworks derived flower shaped nitrogen doped carbon (NC) materials anchored with core-shell Ni-NiO nanoparticles loaded on carbon paper (CP) was fabricated, which equipped with 3D conductive network and hierarchical porous structure physically restrict polysulfide shuttling. Furthermore, well-proportioned Ni-NiO nanoparticles were induced into host to bond with polysulfides further catalyzed the electrochemical reaction. Notably, the S@Ni-NiO@NC/CP exhibited high specific capacity with 1332.9 mAh/g initial specific capacity at 0.5 C and maintained at 896.3 mAh/g after 200 cycles. And S@Ni-NiO@NC/CP can achieves an initial capacity of 1095.7 mA h g−1 even with high sulfur loading of 4.6 mg/cm2. Electrochemical test results indicated that the introduction of Ni-NiO catalyst can improve the kinetics and reduce the reaction overpotential (ηE), and further affects the value of concentration overpotential (ηC) ultimately leads to the increase of battery capacity.