Facile Synthesis of Ultra‐Small Few‐Layer Nanostructured MoSe₂ Embedded on N, P Co‐Doped Bio‐Carbon for High‐Performance Half/Full Sodium‐Ion and Potassium‐Ion Batteries

Abstract

Sodium/potassium-ion batteries (SIBs/PIBs) arouse intensive interest on account of the natural abundance of sodium/potassium resources, the competitive cost and appropriate redox potential. Nevertheless, the huge challenge for SIBs/PIBs lies in the scarcity of an anode material with high capacity and stable structure, which are capable of accommodating large-size ions during cycling. Furthermore, using sustainable natural biomass to fabricate electrodes for energy storage applications is a hot topic. Herein, an ultra-small few-layer nanostructured MoSe₂ embedded on N, P co-doped bio-carbon is reported, which is synthesized by using chlorella as the adsorbent and precursor. As a consequence, the MoSe₂ /NP-C-2 composite represents exceedingly impressive electrochemical performance for both sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). It displays a promising reversible capacity (523 mAh g^-1 at 100 mA g^-1 after 100 cycles) and impressive long-term cycling performance (192 mAh g^-1 at 5 A g^-1 even after 1000 cycles) in SIBs, which are some of the best properties of MoSe₂ -based anode materials for SIBs to date. To further probe the great potential applications, full SIBs pairing the MoSe₂ /NP-C-2 composite anode with a Na₃ V₂ (PO₄ )₃ cathode also exhibits a satisfactory capacity of 215 mAh g^-1 at 500 mA g^-1 after 100 cycles. Moreover, it also delivers a decent reversible capacity of 131 mAh g^-1 at 1 A g^-1 even after 250 cycles for PIBs.