Designing Sandwiched and Crystallized NiMn2O4/C Arrays for Enhanced Sustainable Electrochemical Energy Storage

In this report, novel three-dimensional sandwiched NiMn2O4/C arrays on Ni foam are first synthesized through a general and simple synthetic approach. In this process, the glucose and ultrathin NiMn layered double hydroxide arrays are used as green carbon source and sacrificial templates, respectively. This advanced nanoarchitecture obtained here can not only improve the electronic conductivity due to carbon coating and conductive substrates but can also prevent NiMn2O4 nanoparticles from agglomeration and falling off. The as-prepared sandwiched NiMn2O4/C arrays are more desirable for application in energy storage. When evaluated as supercapacitors, they exhibit ultrahigh specific capacitance (2679 F/g at 1 A/g) and superior stability (2% decay after 6000 cycles). On the other hand, because of the unique structure design, they demonstrate excellent capacity (1346 mAh/g at 500 mA/g), remarkable rate performance, and cyclability for lithium-ion batteries.