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Iron sulfide (FeS) anodes are plagued by severe irreversibility and volume changes that limit cycle performances. Here, a synergistically coupled hybrid composite, nanoengineered iron sulfide/S-doped graphene aerogel, was developed as high-capacity anode material for Li/Na-ion half/full batteries. The rational coupling of in situ generated FeS nanocrystals and the S-doped rGO aerogel matrix boosted the electronic conductivity, Li + /Na + diffusion kinetics, and accommodated the volume changes in FeS. This anode system exhibited excellent long-term cyclability retaining high reversible capacities of 422 (1100 cycles) and 382 mAh g -1 (1600 cycles), respectively, for Li + and Na + storage at 5 A g -1 . Full batteries designed with this anode system exhibited 435 (FeS/srGOA||LiCoO 2 ) and 455 mAh g -1 (FeS/srGOA||Na 0.64 Co 0.1 Mn 0.9 O 2 ). The proposed low-cost anode system is competent with the current Li-ion battery technology and extends its utility for Na + storage., (© 2021 Wiley-VCH GmbH.)

FeS 2 /C core-shell nanofiber webs were synthesized for the first time by a unique synthesis strategy that couples electrospinning and carbon coating of the nanofibers with sucrose. The design of the one-dimensional core-shell morphology was found to be greatly beneficial for accommodating the volume changes encountered during cycling, to induce shorter lithium ion diffusion pathways in the electrode, and to prevent sulfur dissolution during cycling. A high discharge capacity of 545 mAh g -1 was retained after 500 cycles at 1 C, exhibiting excellent stable cycling performance with 98.8 % capacity retention at the last cycle. High specific capacities of 854 mAh g -1 , 518 mAh g -1 , and 208 mAh g -1 were obtained at 0.1 C, 1 C, and 10 C rates, respectively, demonstrating the exceptional rate capability of this nanofiber web cathode., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)