Carbon nanoflakes as a promising anode for sodium-ion batteries

Abstract

The sharp increase in the cost of lithium resource has driven the research on sodium-ion batteries (SIBs) as sodium shares a similar electrochemical property as lithium. Carbonaceous materials are important anodes for rechargeable batteries, but the prevailing graphite only shows a limited activity towards sodium storage. Herein, we demonstrate that carbon nanoflakes serve as an efficient anode material for SIBs, exhibiting a stable capacity of 148[Formula: see text]mAh[Formula: see text]g[Formula: see text] over 600 continuous cycles at 150[Formula: see text]mA[Formula: see text]g[Formula: see text] and an excellent rate capability of 120[Formula: see text]mAh[Formula: see text]g[Formula: see text] at 1500[Formula: see text]mA[Formula: see text]g[Formula: see text]. More importantly, sodium storage in carbon nanoflakes exhibits a pseudocapacitive behavior, possibly due to their larger interlayer spacing and less-ordered structure vs. crystallized carbon.