Building nanoparticle-stacking MoO2-CDs via in-situ carbon dots reduction as high-performance anode material for lithium ion and sodium ion batteries

In this work, we report a new type anode material, MoO2 combined carbon dots (CDs) with nanoparticle-stacking structure via a facile hydrothermal route. Herein, CDs is introduced as the reductant which in-situ reduces Mo-VI to Mo-IV. It is further confirmed that the particles of MoO2 with evenly distributed beset of carbon dots form a nanoparticle-stacking structure. Thanks to this specific structure, the as-made MoO2-CDs manifest high performance in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The capacities maintain 854 and 236 mAh g(-1) at 0.50 A g(-1) after 300 cycles for LIBs and 600 cycles for SIBs, respectively. Furthermore, we explored the structure-stability relationship by the electrochemical measurement and morphology, found the mechanisms of charge/discharge composed of dominant redox reaction and auxiliary intercalation reaction, and explained the characteristics of a high rate performance through kinetic issues and extrinsic pseudocapacitance contributions. This green synthetic method of anode material could make it possible to obtain high-performance alkali-ion batteries and other energy storage devices. (C) 2019 Elsevier Ltd. All rights reserved.