Recently, transition-metal chalcogenides (TMCs) have widely been studied as anode materials for sodium-ion batteries (SIBs) because of their structural characteristics and unusual chemical, physical, and electronic properties. [1-3] However, their practical energy-storage performance is far below the Golden bristlegrass-like unique nanostructures comprising reduced graphene oxide (rGO) matrixed nanofibers entangled with bamboo-like N-doped carbon nanotubes (CNTs) containing CoSe 2 nanocrystals at each node (denoted as N-CNT/rGO/CoSe 2 NF) are designed as anodes for high-rate sodium-ion batteries (SIBs). Bamboo-like N-doped CNTs (N-CNTs) are successfully generated on the rGO matrixed nanofiber surface, between rGO sheets and mesopores, and interconnected chemically with homogeneously distributed rGO sheets. The defects in the N-CNTs formed by a simple etching process allow the complete phase conversion of Co into CoSe 2 through the efficient penetration of H 2 Se gas inside the CNT walls. The N-CNTs bridge the vertical defects for electron transfer in the rGO sheet layers and increase the distance between the rGO sheets during cycles. The discharge capacity of N-CNT/ rGO/CoSe 2 NF after the 10 000th cycle at an extremely high current density of 10 A g −1 is 264 mA h g −1 , and the capacity retention measured at the 100th cycle is 89%. N-CNT/rGO/CoSe 2 NF has final discharge capacities of

Hierarchically well‐developed porous graphene nanofibers comprising N‐doped graphitic C (NGC)‐coated cobalt oxide hollow nanospheres are introduced as anodes for high‐rate Li‐ion batteries. For this, three strategies, comprising the Kirkendall effect, metal–organic frameworks, and compositing with highly conductive C, are applied to the 1D architecture. In particular, NGC layers are coated on cobalt oxide hollow nanospheres as a primary transport path of electrons followed by graphene‐nanonetwork‐constituting nanofibers as a continuous and secondary electron transport path. Superior cycling performance is achieved, as the unique nanostructure delivers a discharge capacity of 823 mAh g−1 after 500 cycles at 3.0 A g−1 with a low decay rate of 0.092% per cycle. The rate capability is also noteworthy as the structure exhibits high discharge capacities of 1035, 929, 847, 787, 747, 703, 672, 650, 625, 610, 570, 537, 475, 422, 294, and 222 mAh g−1 at current densities of 0.5, 1.5, 3, 5, 7, 10, 12, 15, 18, 20, 25, 30, 40, 50, 80, and 100 A g−1, respectively. In view of the highly efficient Li+ ion/electron diffusion and high structural stability, the present nanostructuring strategy has a huge potential in opening new frontiers for high‐rate and long‐lived stable energy storage systems.

Metal–organic framework-templated nitrogen-doped graphitic carbon (NGC) and polydopamine-derived carbon (PDA-derived C)-double coated one-dimensional CoSe2 nanorods supported highly porous three-dimensional microspheres are introduced as anodes for excellent Na-ion batteries, particularly with long-lived cycle under carbonate-based electrolyte system. The microspheres uniformly composed of ZIF-67 polyhedrons and polystyrene nanobeads (ϕ = 40 nm) are synthesized using the facile spray pyrolysis technique, followed by the selenization process (P-CoSe2@NGC NR). Further, the PDA-derived C-coated microspheres are obtained using a solution-based coating approach and the subsequent carbonization process (P-CoSe2@PDA-C NR). The rational synthesis approach benefited from the synergistic effects of dual carbon coating, resulting in a highly conductive and porous nanostructure that could facilitate rapid diffusion of charge species along with efficient electrolyte infiltration and effectively channelize the volume stress. Consequently, the prepared nanostructure exhibits extraordinary electrochemical performance, particularly the ultra-long cycle life stability. For instance, the advanced anode has a discharge capacity of 291 (1000th cycle, average capacity decay of 0.017%) and 142 mAh g−1 (5000th cycle, average capacity decay of 0.011%) at a current density of 0.5 and 2.0 A g−1, respectively.

The introduction of functional interlayers between the cathode and anode in lithium–sulfur battery (LSB) technology results in significant improvements in electrochemical performance. Here, we developed hierarchically structured porous, conductive, and...

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