A combination of optimization methods has been developed to help compensate for the weak points of molybdenum disulfide (MoS2), including poor electronic conductivity and large volume expansion, for better exhibiting its advantages such as high capacity and stability in the fields of lithium/sodium-ion batteries (LIBs/SIBs). In the study, nitrogen-doped three-dimensional graphene supporting MoS2 hydrangea nanoflowers with a nitrogen-doped carbon intercalation (MoS2/NC@N3DG) hierarchical composite has been designed and prepared in a simple one-step hydrothermal and annealing way. The distinctly expanded spacing between MoS2 interlayers can facilitate the ion diffusion and the doped nitrogen atoms can markedly improve the electronic conductivity. Therefore, the MoS2/NC@N3DG composite electrode shows outstanding rate capability and excellent cycling performance for both LIBs (1497/1300 mA h g–1 at 0.2/1 A g–1 after 200/500 cycles) and SIBs (513/364 mA h g–1 at 0.2/1 A g–1 after 200/500 cycles). This work provides a promising scheme for designing advanced two-dimensional layered metal dichalcogenide materials for high-performance LIBs and SIBs.

Developing hybrid metal−organic frameworks (MOFs) with ordered structure is significant to obtain promising electrode materials for supercapacitors. Herein, the special electrodes of CuCo 2 O 4 /NiCo-MOF nanoflake vertical arrays are constructed on Ni foam by using the CuCo 2 O 4 nanorods as a selfsacrifice template. Because of the multidirectional interconnected channels of spinel CuCo 2 O 4 , great electrochemical activity of NiCo-MOF, well-arranged morphology, and synergy effect at the interface, the resulting CuCo 2 O 4 /NiCo-MOF nanoflakes exhibit remarkable specific capacity (12.81 F/cm 2 or 1423 F/g at 2 mA/ cm 2 ) and excellent rate performance (remaining 79.2% at 30 mA/ cm 2 ). The asymmetric supercapacitor assembled by CuCo 2 O 4 / NiCo-MOF and an activated carbon electrode shows excellent energy density of 0.48 mWh/cm 2 at a power density of 1.50 mW/cm 2 . This work inspires insight into exploiting hybrid MOFs with highly aligned arrays for energy storage.

The two-dimensional layered material tin disulfide (SnS 2 ) has a high theoretical capacity for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its combination of conversion and alloying reactions during the charge-storage process. However, the intrinsic poor conductivity and huge volume changes impede its practical applications. In this work, a design of in situ growth and polymerization is developed to synthesize polypyrrole wrapped SnS 2 vertical nanosheet arrays grown on nitrogen-doped three-dimensional graphene (PPy@SnS 2 @N3DG). The PPy@SnS 2 @ N3DG composite, with the unique free-standing hierarchical structure and the synergy of three components, exhibits excellent rate capability and superior cycling stability. Based on the features of high capacity, lightweight, and facile preparation, the PPy@SnS 2 @ N3DG composite can be considered as a promising electrode for energy storage devices.

The hierarchically porous iron phosphide nanospindles with nitrogen–phosphorus-codoped carbon coatings (FeP@NPC) are fabricated via a combination of hydrothermal synthesis and subsequent phosphating treatment, which is extensively researched for elevating the outstanding performance of lithium-ion batteries (LIBs). The as-prepared FeP@NPC nanocomposite manifests a distinguished specific capacity of 1100 mA h g–1 after 200 cycles at 0.2 A g–1, a ranking rate performance with a high capacity of ∼600 mA h g–1 at 5 A g–1, and a reversible long cycling capacity of 951.7 mA h g–1 after 800 cycles at 1 A g–1. The superior properties can be ascribed to the joint contribution of the well-designed porous nanostructure and conductive N, P-codoped carbon coating, which simultaneously facilitates efficient transmission of lithium ions and electrons, contributes to mild volume expansion, and elevates structural stability during the reversible charge–discharge process.

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