摘要
Lithium-sulfur batteries(LSBs)are considered as the promising solution to replace conventional lithium-ion batteries due to satisfactory energy density.In recent times,the LSBs field has been found to face some difficulties in exploring practical applications in which cycling stability and cycle life are awful owing to the shuttling effect of lithium polysulfides(LiPSs)and low sulfur utilization.In this work,by synthesizing Co_(3)Se_(4) nanoparticles onto N-doped carbon(NC)polyhedra interconnected with carbon nanotubes(CNTs),NC@Co_(3)Se_(4)/CNTs is proposed as a multifunctional sulfur carrier.The Co_(3)Se_(4) nanoparticles fleetly catalyze the conversion of LiPSs and availably immobilize LiPSs.Meanwhile,the NC polyhedral skeleton enhances the electronic conductivity of active sulfur,while the CNTs facilitate Li+diffusion and supply a mass of conductive channels.Density-functional theory(DFT)calculations demonstrate the relevant mechanisms.That is to say,the NC@Co_(3)Se_(4)/CNTs benefit from the synergistic effect of Co_(3)Se_(4) nanoparticles(highly catalytic ability and strong adsorbability for LiPSs)and the special carbonaceous structure,rapidly converting LiPSs and inhibiting the shuttle of LiPSs.Therefore,lithium-sulfur battery assembled with S/NC@Co_(3)Se_(4)/CNTs cathode as well as nitrogen and sulfur co-doped carbon-coated polypropylene(N,S-C/PP)separator possesses a high initial discharge capacity of 1413 mAh·g-1 at 0.12C and persistently circulates for 1000 cycles at 1C with a capacity attenuation rate per cycle of 0.034%.This work provides a realistic idea for the use of transition metal selenide in the field of high-performance LSBs.
基金
supported by the National Natural Science Foundation of China(Nos.52130101 and 52271217)
the Project of Science and Technology Development Plan of Jilin Province in China(Nos.20210402058GH,20220201114GX).
