Design and synthesis of multiroom-structured metal compounds-carbon hybrid microspheres as anode materials for rechargeable batteries

A novel structure denoted as a "multiroom carbon hybrid", which comprises empty voids dispersed in metal oxide-, sulfide-, and selenide-carbon composites is introduced. Multiroom-structured carbon hybrid microspheres of single component Co3O4 and NiO and multicomponent (Ni0.5Co0.5)O-x were successfully prepared using a one-pot spray pyrolysis process. Liquid-liquid phase segregation during the spray pyrolysis process is a key requirement for generating multiroom-structured metal oxide-carbon hybrid microspheres. Multiroom-structured CoSe2-graphitic carbon (GC) and CoS2-CoS-GC hybrid microspheres were also prepared using a simple post-treatment process. Multiroom-structured CoSe2-GC hybrid microspheres have superior sodium-ion storage properties to bare CoSe2 microspheres. The reversible discharge capacities of the CoSe2-GC and CoS2-CoS-GC hybrid microspheres for the 100th cycles at a current density of 0.2 A g(-1) are 393 and 334 mA h g(-1), respectively. The discharge capacity of the multiroom-structured Co3O4-C hybrid microspheres for lithium-ion storage at a high current density of 3 A g(-1) for the 150th cycle is 1243 mA h g(-1). (C) 2016 Elsevier Ltd. All rights reserved.