Abstract

In order to pursue high-performance lithium and sodium ion batteries (LIB, SIB) with both high energy and power densities, in this work, we design and construct light bind-free integrated positive electrodes by combing VO₂@(GQD, graphene quantum dots) nanoarrays and self-supported ultralight graphene foam (GF). This multivariate integrated electrode combines the strategies of nanoporous design and conductive composite design. Such an integrated electrode not only possesses merits of nanostructures with short ion/electron diffusion path, but also shows improved structural stability and omni-bearing charge transfer modification for VO₂ by the GQDs and GF. As positive electrodes for LIBs and SIBs, the as-prepared GF-VO₂@GQD nanoarray exhibits superior Li and Na ion storage properties with high specific capacity, high-rate capability and high-rate cycling stability. Impressively, it delivers a noticeable Na storage capacity of ~300 mAh g^-1 at 0.5 C as well as a capacity of ~110 mAh g^-1 at 60 C after 1500 cycles. It is prospected that such integrated electrode design strategy can also be extended to fabricate other advanced electrode materials for applications in supercapacitors, full cells and catalysis.

© 2015 Optical Society of America