Construction of sandwich-type hybrid structures by anchoring mesoporous ZnMn2O4 nanofoams on reduced graphene oxide with highly enhanced capability

We have developed a sandwich-type hybrid nanostructure by anchoring foam-like zinc manganate (ZnMn2O4) on reduced graphene oxide (rGO) (rGO/ZnMn2O4 NFs) via a trisodium citrate (TSC) assisted solution reaction followed by a post-calcination treatment. The interconnected sheet-like ZnMn2O4 subunits have assembled into mesoporous nanofoams on rGO sheets with the beneficial help of TSC. When cycled at a current density of 180 mA g(-1), the hybrid rGO/ZnMn2O4 NF anodes present a high discharge capacity of 945 mA h g(-1) even after 150 cycles with long cycle durability and good rate capability. Such highly enhanced electrochemical performance is ascribed to the sandwich-type hierarchical foam structure effectively promoting the ion/charge transport whilst buffering volume variations upon continuous discharge/charge cycling. These results indicate that a porous anode scaffold with conductive connections is a promising structural design for rechargeable batteries with superior reversible lithium storage capability.