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The volume-change and poor conductivity issues of sulfur severely restrict the performance of lithium-sulfur (Li–S) batteries. Herein, we present a novel spring-shaped composite in which the sulfur is coated on helix-structured SiO 2 @hydrogel nanowires. The helix composite provides a buffer space for the volume-change of sulfur during charge and discharge; and the hydrogel polyaniline (PANI) coating improves the conductivity of the electrode and enables interaction with sulfides which is demonstrated by first-principle modelling. The prepared SiO 2 @C@PANI/S nanowires exhibit a stable capacity of 940 mAh g−1 after 120 cycles at a rate of 0.1C, along with a good Coulombic efficiency of 99.8%. The nanowires-based cathode also shows a high rate-performance even after three rounds of repeated measurements. The high performance and the general preparation method would enable the composite to be able to find significant applications for electrochemical energy-storage. Image 1 • A novel helix-structured nanowire is presented. • Composite cathodes exhibit a high electrochemical performance. • Helix structure enables stable energy-storage. • Ultra-stable rate-performance is achievable. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel magnetic nanoparticles-assembled composite is presented for Li-S battery. • One-dimensional chain-like structure accommodates volumetric change. • Magnetic composite suppresses the shuttle effect of polysulfides. • Repeatable rate-performance is achieved. Lithium-sulfur battery is of great interest because of high theoretical energy–density and low cost. While the large volumetric change of sulfur and shuttle effect restrict its development. Here, we develop a one-dimensional chain-like Fe 3 O 4 prepared through the self-assembly of magnetic particles as sulfur host. The Fe 3 O 4 @S cathode shows a capacity 457 mAh g−1 after 150 cycles, and a 99% Coulombic efficiency. In addition, rate-performance after three rounds delivers stable capacities after repeated measurements. The electrochemical performance is ascribed to the one-dimensional nano-chain structure provides fast pathways for electron transportation, and accommodates volumetric change of sulfur in charge–discharge. Those findings provide a potential strategy to develop high-performance nanocomposite for secondary batteries. [ABSTRACT FROM AUTHOR]