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Manganese-based chalcogenides would be of latent capacity in serving as anodes for assembling lithium- and/or sodium-ion batteries (LIBs/SIBs) due to their large theoretical capacity, low price, and low-toxicity functionality, while the low electroconductivity and easy agglomeration behavior may impede their technical applications. Here, a solid-state solution of MnS 0.5 Se 0.5 nanocubes in rock-salt phase has been synthesized for the first time at a relatively low temperature from the precursors of Mn(II) acetylacetonate with dibenzyl dichalcogens in oleylamine with octadecene, and the MnS 0.5 Se 0.5 nanocubes have been assembled with N-doped graphene to form a new kind of heterostructured nanohybrids (shortened as MnS 0.5 Se 0.5 /N-G hybrids), which are very potential for the fabrication of metal-ion batteries including LIBs and/or SIBs. Investigations revealed that there have been dense vacancies generated and active sites increased via nonequilibrium alloying of MnS and MnSe into the solid-solution MnS 0.5 Se 0.5 nanocubes with segregation and defects achieved in the low-temperature solution synthetic route. Meanwhile, the introduction of N-doped graphene forming heterojunction interfaces between MnS 0.5 Se 0.5 and N-doped graphene would efficiently enhance their electroconductivity and avoid agglomeration of the active MnS 0.5 Se 0.5 nanocubes with considerably improved electrochemical properties. As a result, the MnS 0.5 Se 0.5 /N-G hybrids delivered superior Li/Na storage capacities with outstanding rate performance as well as satisfactorily lasting stability (1039/457 mA h g -1 at 0.1 A g -1 for LIBs/SIBs). Additionally, full-cell LIBs of the anodic MnS 0.5 Se 0.5 /N-G constructed with cathodic LiFePO 4 (LFP) further confirmed the promising future for their practical application.

Iron phosphorus triselenide (FePSe 3 ) is attractive for energy applications owing to its interesting layered geometry, electronic structure, and physiochemical property, while it is limited in actual application because of a very long fabrication time of over 7 days. Herein, we report a new synthetic route to a high-quality sheetlike hybrid of iron phosphorus triselenide nanocrystals coated with graphitic carbon (FePSe 3 /C) as an alternative kind of van der Waals heterostructures for the first time via a pyrolytic process at 600 °C from the precursors of ferrocene, red phosphorus, and selenium in a quartz tube with a significantly shortened reaction time of 24 h and even down to 30 min. Investigations demonstrated that the component phase of FePSe 3 in the layered FePSe 3 /C hybrid nanosheets is the rhombohedral phase, and the hybrid nanosheets other than bulk crystals are about 15 nm in thickness. Acting as a cathode in fabricating half-cell sodium-ion batteries, the layered FePSe 3 /C hybrid nanosheets exhibited remarkable performance. Typically, when current density was set as 50 mA g -1 , the hybrid nanosheet-assembled battery exhibited a capacity of 182.7 mA h g -1 after performing over 50 cycles, and the nanosheet battery exhibited a capacity of 142 mA h g -1 after performing for 200 cycling trials at 1 A g -1 in the 0.8-2.2 V voltage window. Meanwhile, the layered FePSe 3 /C hybrid nanosheets also exhibited very high rate capabilities at a relatively large current density in the present study, that is, 172 and 95 mA h g -1 under typical performing conditions at 0.5 and 5 A g -1 , respectively.