Pseudocapacitance dominated Li3VO4 encapsulated in N-doped graphene via 2D nanospace confined synthesis for superior lithium ion capacitors

A pseudocapacitance dominated anode material assembled from Li3VO4 nanocrystals encapsulated in the interlayers of N-doped graphene has been developed via a facile 2D nanospace confined strategy for lithium ion capacitors (LICs). In this contribution, the N-doped graphene synthesized by a faicle solid state reaction using C3N4 nanosheets as template and glucose as carbon source provides sufficient 2D nanospace for the confined and homogeneous growth of Li3VO4 at the nanoscale, and simultaneously efficiently anchors each nanobuilding block inside the interlayers, thus realizing the utilizaiton of full potential of active components. The so-formed 3D hybrids not only ensure intimate electronic coupling between active materials and N-doped graphene, but also realize robust structure integrity. Owing to these unique advantages, the resulting hybrids show pseudocapacitance dominated lithium storage behaviors with capacitive contributions of over 90% at both low and high current rates. The LVO@C@NG delivers reversible capacities of 206 mAh/g at 10 A/g, capacity retention of 92.7% after 1000 cycles at 2 A/g, and a high energy density of 113.6 Wh/kg at 231.8 W/kg for LICs.