Rock-Salt MnSSe Nanocubes Assembled on N-Doped Graphene Forming van der Waals Heterostructured Hybrids as High-Performance Anode for Lithium- and Sodium-Ion Batteries.

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 MnSSe 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 MnSSe nanocubes have been assembled with N-doped graphene to form a new kind of heterostructured nanohybrids (shortened as MnSSe/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 MnSSe nanocubes with segregation and defects achieved in the low-temperature solution synthetic route. Meanwhile, the introduction of N-doped graphene forming heterojunction interfaces between MnSSe and N-doped graphene would efficiently enhance their electroconductivity and avoid agglomeration of the active MnSSe nanocubes with considerably improved electrochemical properties. As a result, the MnSSe/N-G hybrids delivered superior Li/Na storage capacities with outstanding rate performance as well as satisfactorily lasting stability (1039/457 mA h g at 0.1 A g for LIBs/SIBs). Additionally, full-cell LIBs of the anodic MnSSe/N-G constructed with cathodic LiFePO (LFP) further confirmed the promising future for their practical application.