Molybdenum (Mo)-based compounds with properly engineered nanostructures usually possess improved reversible lithium storage capabilities, which offer great promise to boost the performance of lithium-ion batteries (LIBs). Nevertheless, a lack of efficient and high-yield methods for constructing rational nanostructures has largely restricted the application of these potentially important materials. Herein we demonstrate a metal-organic frameworks (MOFs) mediated strategy to successfully synthesize a series of one-dimensional Mo-based/carbon composites with distinct nanostructures. In this process, starting from well-designed MoO nanorods, the crystal control growth is first proposed that a layer of MOFs is achieved to be controllably grown on surfaces of MoO, forming an obvious core-shell structure, and then the adopted precursor can be in situ transformed into MoO or MoC which are both well confined in conductive porous carbons through direct carbonization at different temperatures, where the MOFs shell serve as both carbon sources and the reactant to react with MoO simultaneously. Benefiting from this design, all optimized products exhibit enhanced electrochemical performances when evaluated as anode materials for LIBs, especially the hollow MoO/C and core-shell MoC/C electrodes, show best reversible capacities up to 810 and 530 mAh g even after 600 cycles at a current density of 1 A g, respectively. So this work may broaden the application of MOFs as a kind of coating materials and elucidates the attractive lithium storage performances of molybdenum-based compounds.

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Revealing how formation protocols influence the properties of the solid-electrolyte interphase (SEI) on Si electrodes is key to developing the next generation of Li-ion batteries. SEI understanding is, however, limited by the low-throughput nature of conventional characterisation techniques. Herein, correlative scanning electrochemical cell microscopy (SECCM) and shellisolated nanoparticles for enhanced Raman spectroscopy (SHINERS) are used for combinatorial screening of the SEI formation under a broad experimental space (20 sets of different conditions with several repeats). This novel approach reveals the heterogeneous nature and dynamics of the SEI electrochemical properties and chemical composition on Si electrodes, which evolve in a characteristic manner as a function of cycle number. Correlative SECCM/SHINERS has the potential to screen thousands of candidate experiments on a variety of battery materials to accelerate the optimization of SEI formation methods, a key bottleneck in battery manufacturing.

Sodium-ion batteries (SIBs) attract more attention because of sodium’s abundant availability, affordable price, and potential to be an effective anode material. Meanwhile, carbon-based materials provide the most promising anode materials. Because of the large radius of sodium ions, SIBs do not exhibit favorable electrochemical performance. Introducing heteroatoms into the carbon-lattice is an effective strategy to enlarge the interlayer space of carbon-based materials which can improve carbon’s electrochemical performance. In addition, anode materials with a surface-induced capacitive process can enhance the SIB’s electrochemical performance because its capacitive process increases the kinetics of ion diffusion. Here, we describe an SIB’s anode material containing nitrogen and sulfur co-doped graphene sheets [denoted as poly­(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT)/reduced graphene oxide (RGO)] which are synthesized via carbonization of PDMcT polymerized on the surface of GO. PDMcT/RGO exhibited high capacities (240 mA h g–1 at 500 mA g–1), improved rate performance (144 mA h g–1 at 10 A g–1), and good cycling stability (153 mA h g–1 after 5000 cycles at 5000 mA g–1). These unique results are attributed to the enlarged interlayer spacing and electronic conductivity from the heteroatoms which facilitate the sodium ion’s insertion and electron transport. These results represent that PDMcT/RGO is a great potential anode material for SIBs.